Background information · Ernst has perfected the cloning method of avocado to produce the final...

Background information: In early July I received a draft of a white paper entitled “Avocado Plant Breeding Strategy 2013-2033” authored by Jonathan Dixon. I carefully reviewed this document and had several concerns over its contents. In order to insure that my concerns were substantiated I wrote to several scientists asking their opinion of the draft breeding strategy especially regarding the concepts, assumptions and goals brought forth by the author. I am providing you with their responses which could serve as material for thought from different perspectives. The comments from the individuals that I queried came primarily in email format. A few wrote lengthy letters and 2 made comments directly through “track changes” onto the word document. These latter three as well as my comments are presented in table format at the end of these responses. Reuben Hofshi

Dr. Jose Chaparro is a member of the University of Florida, Dept. of Horticultural Sciences. Dr. Chaparro

has a long history in fruit tree breeding. He was a citrus fruit breeder for several years for USDA‐ARS in

Ft. Pierce, FL before accepting his current position at the University of Florida. Dr. Chaparro currently

oversees the stone fruit breeding program at the university plus continuing his work with breeding for

cold tolerant citrus. He has recently started a small program looking for cold hardy avocado.

Dr. Chaparro wrote the email below. Additionally he made comments directly into the draft document.

These further comments are included in a table summarizing direct comments into the draft document.

Hello Reuben I have read the attached document and made some comments that you are free to use in your response. In summary it looks like the CA avocado industry is on course to repeat the mistakes of the apple growers with red delicious and the citrus growers with sunburst mandarin. The growers were happy with those varieties until someone overseas bred a better variety and theirs was obsolete. Jose Dr. Jose X. Chaparro Associate Professor Horticultural Sciences Department University of Florida

Dr. Andre Ernst is the owner of Allesbeste Nursery in Tzaneen, South Africa. Dr. Ernst has a PhD in

horticultural sciences from the University of Pretoria. His nursery grows and markets avocado trees

worldwide. Dr. Ernst has perfected the cloning method of avocado to produce the final clonal avocado

tree without the nurse seed. Dr. Ernst also is the patent holder for the Maluma Hass and the developer

of the Bounty avocado rootstock.

Hi Reuben

Please find attached my remarks to the attached draft Avocado Plant Breeding strategy. I agree this document is flawed and missing the point. Hope my contribution will assist you in your efforts to convince them to the contrary.

Kind regards

Andre

Dr. A.A Ernst • Mr. E.D Ernst • Mrs. Liezel Ernst • Mr Z.R Ernst

REMARKS ON: AVOCADO PLANT BREEDING STRATEGY 2013-2033

A DRAFT DOCUMENT TO BE PRESENTED TO THE CALIFORNIA AVOCADO COMMISSION BOARD DURING MID AUGUST

BACKGROUND According to the draft document (Appendix 2) Dr Bob Berg in 1976 listed 35 traits for scion breeding and 13 traits for rootstock breeding. It has been concluded that such lists of traits are quite extensive and detailed and it would appear to be unrealistic to create a new cultivar with all desirable traits within a reasonable timeframe. To guide plant breeders it is necessary to put priorities on the most desirable traits by selecting a smaller number. Relevant goals and traits were identified through industry consultation. Current Plant Breeding research projects funded by the CAC includes the following: Root rot resistant rootstocks

Primary Investigator: None (Temporary: Dr Akif Eskalen, Former: Dr Greg Douhan) Objectives: To breed a rootstock resistant to Phytophthora cinnamomi and for salinity resistance. Activity: Evaluation of seedlings exposed to Phytophthora cinnamomi and planned salinity to select for root rot tolerance, planting of selections at UCR or South Coast Research and Extension Center in Irvine (SCRES) and propagation of selections for planting on growers properties. Some analysis of the population genetics of Phytophthora cinnamomi strains in California. CAC funding in 2012-2013 CAC fiscal year: $150,000.

New varieties

Primary Investigator: Dr Mary Lu Arpaia Objectives:

o To breed new varieties with higher productivity, lower alternate bearing, large sized fruit, consistent ripening during the season and are comparable with Hass for eating quality and postharvest storage quality.

o To assess rootstock scion interactions. o To evaluate and exchange promising new varieties from around the world. o To maintain an avocado germplasm collection.

Activity: o Evaluation of seedlings selected from crosses between different varieties, increased numbers

of selections at SCRES and then on growers properties. o Evaluation of new fruit varieties grafted onto rootstocks planted in field trials, some on growers

properties. Taste testing of new fruit varieties. o Evaluation of avocado cultivars sourced from other avocado plant breeding and evaluation

programs. o Germplasm maintenance of avocado varieties at SCRES.


CAC funding in 2012-2013 CAC fiscal year: $211,354. Genetics

Primary Investigator: Dr Mary Lu Arpaia Objectives: To utilize the UC, Riverside mapping population to resequence the population to identify more markers associated with desirable traits to use in marker assisted selection of seedlings. Activity: Map phenological traits using genetic technology to use as markers for selecting seedlings using a small population of Gwen crosses. Collaboration with USDA NGR (National Germplasm Repository) Miami-Dade, Florida.

CAC funding in 2012-2013 CAC fiscal year: $19,126. The total funding of Plant Breeding by CAC in 2012-2013 CAC fiscal year is therefore $380,480. The funding is likely to be increased to allow for the intended increased effort in genetics research and commercialization. The suggested level of funding annually is $500,000, a 30% increase over current spending. According to the draft document: “this investment will only work if the plant breeding program is rationalized and a comprehensive project plan is developed by a program leader, preferably a plant breeder, that integrates traditional plant breeding and new technology along with generating the information needed for market development and cultural management.” It has been emphasized that, for any research program, good oversight is essential to ensure the program maintains its focus on the desired outcomes SUMMARY / PROPOSAL / STRATEGY According to the draft document the “current program has partial alignment with the conclusions of the CAC Board and do not adequately address that the emphasis of the plant breeding program should be on rootstocks for salt tolerance and root rot resistance. The genetics effort at UC Riverside is limited compared to the significantly greater genetics research being conducted by the USDA at Miami-Dade, Florida. For example the mapping population of trees used at UCR is 200 trees at two sites of Gwen crosses compared to two populations of 750 trees each of West Indian, Guatemalan and Mexican crosses.” As a present relationship exists between UCR and the USDA, as expressed under Genetics Actvity above, one would assume that the present breeding program at UCR will have access to genetic material as mapped by the USDA if needed, for the same reason that “the USDA is sharing their much more detailed genetic maps with the Mexican researcher to help complete the avocado genome.” The above-mentioned reasons as presented in the draft document do not clarify why and how “the plant breeding projects could be more (should be) integrated and focused into a single project.” Proposed plant breeding activity (as per draft document)

1. “Place rootstock breeding, breeding of new fruit types and genetics under one project and request a proposal for a plant breeding program where the goals and traits are defined.”

2. “The strategy to pursue is to solve long term problems.” 3. “Proposed goal: To create an avocado root stock that is resistant to root rot caused by Phytophthora

cinnamomi and is tolerant to salts … and chlorides … that is easy to propagate and compatible with a wide range of fruit types.”

4. “Traits desired: Phytophthora cinnamomi resistant Salt tolerant to xxx TDS – value to be determined Chloride tolerant to xxxx ppm – value to be determined Easy to propagate Compatible with all scion varieties.”

5. “Engage a trained plant breeder as program leader for a team of specialists that includes plant pathologists, entomologists, soil scientists, plant physiologists and horticulturalists.”

6. “Develop a formal partnership with UC, Riverside and USDA ARS to manage intellectual property rights.“

7. “Preserve the existing germplasm as a resource for genetic studies.”


8. “Create three sites within the south, mid and north avocado growing regions where the horticultural performance of varieties can be measured.”

9. “Ramp down the scion breeding program by stopping all new propagation, seed collecting and planting of advanced selections. Complete the evaluation of advanced material in tier 3 plantings and stop advancing material from tier 1 to tier 2 to tier 3.”

10. “`Seek CAC Board approval for the release of new varieties and include a request for funding of the commercial development.”

From the above mentioned proposal there is a clear intension to find approval from the CAC Board to move away from the current Breeding program as elaborated on in the Background section above. This entails the “ramping down” of the long standing and internationally renowned scion breeding program (9 above) conducted by the UCR and moving towards the “proposed goal” namely to create an avocado root stock resistant to root rot (Phytophthora cinnamomi) and tolerant to salts and chlorides (3 and 4 above). Presently the rootstock program only has a temporary primary investigator. From the proposal above as well as the tone of the 2 appendixes to the document one can assume that the intention is to scale down the scion breeding program in favor of the rootstock breeding program. The only reference to the breeding of new fruit types (scion) is by placing it under one project together with rootstock breeding and genetics. A plant (assumedly scion??) breeding program where the goals and traits are to be defined awaiting a proposal. Other than the reference to the intended partnership with UCR and USDA ARS to manage intellectual property rights (6 above) no reference is made to the intended future relationship with UCR and in particular Dr Mary Lu Arpaia, primary investigator for New varieties and Genetics. The ramping down of the scion breeding program mentioned under 9 above clearly does not include the other responsible research fields (current program) as indicated in the background above. It needs to be mentioned that of the $380,480 CAC current funding (2012-2013 fiscal year) for plant breeding, $211,354 (55,6%) was allocated to New varieties under the auspices of Dr Arpaia. Preserving the existing germplasm as a resource for genetic studies (7 above) does not include or imply the identifying of more markers associated with desirable traits to use in marker assisted selections as being the objective of the current Genetics project. This project, of which Dr Arpaia it also the primary investigator, received a CAC funding of $19,126 for the 2012-2013 CAC fiscal year. The total responsibility of Dr Arpaia (UCR) of the CAC funding of plant breeding is therefore $230,480 (60,6%). The proposal above is unclear about the future relationship with the UCR and/or the SCRES and/or Dr Arpaia. According to the draft document “the tools to improve the plant breeding process that show the most promise are the new genetic technologies.” Together with the intended ramping down of the scion breeding program, the question is if the preserving of the existing germplasm as a resource for genetic studies (7 and 9 above) implies the consideration of other more modern breeding techniques. The author of the draft document in his concluding paragraph actually answers this question with the following phrase: “Unfortunately, the genetic tools are still in a development phase and are likely to take many years before significant gains in efficiency are made within the plant breeding program. It will take time to identify the genes of interest associated with specific traits and how their manipulation can be utilized in the development of new cultivars. The genetic work may allow the faster development of new cultivars but there will remain an extended period of testing to be sure the traits are expressed in the field. A further unknown is the acceptability of genetically engineered or enhanced plants to the market.” After a series of strategic discussions the CAC Board, at a recent meeting held on 30 May 2013, concluded that the most support is for breeding new rootstocks to solve production issues rather than to breed new fruit types to realize marketing opportunities. Apparently the Board was convinced that the existing Californian varieties provide the necessary traits and maturity dates to achieve the diversification needs of the industry. According to the draft document “new fruit types were not considered a high priority for breeding but there was strong support for using existing non-Hass avocado varieties, e.g. Reed, GEM, Gwen and others, to diversify the California avocado industry for year round California avocado supply.” This is contrary to the remark in appendix 1 of the draft document indicating the scion cultivars GEM and Gwen, as the Thomas rootstock, to be a failure commercially. “The need for new fruit types was determined to be less urgent than the need to solve the immediate production issues such as salt management. From the Board meeting the general consensus was that the emphasis of the breeding program should be on new rootstocks and evaluation of existing non-Hass varieties.” By abandoning the present scion breeding program without putting a successful alternative in place might have a serious effect on the competitiveness of the Californian Avocado industry in its own market in future. As a consequence the Californian Avocado industry would be perceived as vacating its leading


position in plant breeding internationally. As indicated in appendix 1 of the draft document: “trees with characteristics of slow growth, dwarfing or fruit production off short branches would allow different planting and pruning systems to be used and will reduced labor costs for pruning and pest management thereby lowering costs and improving grove profitability.” This is highly unlikely if not impossible to achieve through the proposed CAC rootstock breeding program. CONCLUSION The approval by the CAC Board of the proposed plant breeding activity in its present format would have serious consequences. It is believed that, as the draft document does not provide enough detail leaving too much room for speculation, the CAC Board would not be in a position to take a responsible decision in the interest of the California Avocado industry, without putting its standing as a renowned international avocado breeder at risk. Compiled by Dr AA Ernst Allesbeste 6 July 2013

Dr. Inaki Hormaza is the lead horticulture research for the IHSM la Mayora ‐ CSIC research station in

Málaga, Spain. Dr. Hormaza is well known for his work on genetic relationships and research on

genotypic sequencing for annonas. He has also led recent research investigating the role of starch and

other factors in avocado fruit set.

Dear Reuben, I'm glad to hear from you again although I would have liked to hear better news than the ones that you are sharing with me. I went through the document and here go some thoughts that I hope can be useful for you. I'll be happy to discuss with more detail with you if you need any additional information that I could provide: • I think that the statements “The Board discussion seemed to conclude that many of our existing varieties provide the necessary traits and maturity dates to achieve the diversification needs of the industry (Page 1, Paragraph 1, Sentence 5)” and “9. Ramp down the scion breeding program by stopping all new propagation, seed collecting and planting of advanced selections. Complete the evaluation of advanced material in tier 3 plantings and stop advancing material from tier 1 to tier 2 to tier 3. (Page 4, Point 9 under “Proposed breeding program activity)” are totally wrong since this could be true maybe (I even doubt that) for the short term but when looking at breeding in fruit trees this is always a long‐term shot. The seeds you plant today will provide results in about 20 years; so from a breeding perspective this doesn't make any sense because if one day you decide to resume the breeding program you should start again from scratch. • “The net result of the strategic discussion is there is the most support for breeding new rootstocks to solve production issues and less support to breed new fruit types to realize marketing opportunities”: what is wrong with supporting both variety and rootstock breeding? Why should you choose between one of the two? Rootstock research should also continue, of course, and I think that this is adequately reflected in the document; but that doesn't mean that the variety breeding program should necessarily be discontinued. • It seems that one of the problems is the need to create a new avocado market for new varieties. I don’t think that this is the responsibility of the scientists involved in breeding new varieties but of the industry. In relation to this, what I missed in the report is an analysis of where the California avocado industry should be in 10‐20 years, especially in a document entitled strategy 2013‐2033. What will be its niche? Will it make sense to produce Hass or Hass‐like varieties to compete with other avocado producing countries in Central and South America with lower production costs or the future of the industry in California should be linked to develop a different variety focused on the local US market? In this sense, is, for example, good storage life for shipping an interesting trait for a new variety in California? • The point on the control of patent rights of the new varieties is interesting. Probably this is something that should be discussed with the university in order for CAC to have a fairer share on the revenues of new varieties that can be cultivated in other countries besides the US. • Genomic tools. Reading the document the impression that I got was that there is an interest from the CAC Board in increasing the collaboration with the USDA group in Florida who is also somehow involved in the sequencing of the avocado genome with the Mexicans, although I’m not sure to which extent. However, it should be stressed that the important factor here should be the germplasm and the plant material. Many laboratories worldwide can do genomic analyses (we do that also in my lab) but that only makes sense when you have very good phenotyping and good germplasm collections. I would think that the Clegg lab (and several other groups) could do molecular analyses similar to those performed by the group in Florida but

closer to the collections and not focused in West Indian genotypes. On the other hand, I'm not sure about how open the Mexicans will be to share their genomic sequences. Perhaps it could be of interest to establish an international consortium to sequence a genome of avocado but with the commitment of making the sequences fully available. On the other hand, a sequenced genome without proper phenotyping is useless. So from my point of view, the goal would be to have a strong genomics lab at UC working closely to the groups involved in rootstock and variety breeding. • International collaboration. Some of the concerns raised in the document (especially for rootstock breeding) are shared by different avocado producing countries so perhaps an effort to promote collaboration with other Institutions could be desirable. Best wishes, Inaki

Dr. Vered Irihimovitch is a researcher at the Volcani Research Center, Agricultural Research Organization

in Bet Dagan, Israel. Dr. Irihimovitch is the research leader for the avocado plant improvement program

currently funded by the avocado growers in Israel. This program is focused primarily on variety

development.

Hello Reuben,

I read the document you sent and here are my comments.

I do not think that it would be a good idea to combine the breeding program of cultivars, together with the rootstock breeding program. They both must exist on their own, as they require different work strategies.

The importance of a breeding program which has the aim of creating new cultivars is fundamental for the industry, especially when relying on only one main product. What would happen if a sudden disaster would occur (ambrosia beetle damage for example).

With that being said, I see similar trends of thoughts of growers, here in Isreal as compared to California. For example, in the present Israeli avocado breeding program, only the state (the Ministry of Agriculture) is funding the program. Yet, the program in Israel will be funded only for 10 years. After this period of time, it is agreed that the breeding program will continue. Its funding at that time will come from income from royalties from commercialization of the cultivars internationally.

As a matter of fact, the Israeli growers initially strongly rejected the idea of renewing the program. They did not want to contribute to it stating that this kind of program is too "heavy" for the industry. However, once the program was funded by the state, they decided to collaborate. Now the agreement is that the evaluation of new cultivars, in the semi commercial plots, will be performed by them without having to pay the extra costs. In turn, all Israeli growers will be able to grow any new cultivars without paying royalties. I know that the situation in Israel and California is different, but perhaps CAC growers might be interested to hear how the avocado breeding program is being carried out in Israel.

I hope this is helpful.

Best, Vered.

Dr. Stefan Kohne is the manager for Westfalia Technological Services in South Africa. Dr. Kohne has 30+

years experience in avocado research. His research has spanned the spectrum of plant growth

regulators, high density and canopy management, germplasm collection and plant improvement.

Greetings Reuben, I know that Zelda answered you on that same matter. Please regard Zelda’s reply as the representative reply for Westfalia in general – we discussed that matter together. Wishing you & the plant breeding program all the best Regards Stefan

Dr. Emi Lahav is a retired researcher from the Volcani Agricultural Research Organization in Israel. He

directed the renowned Akko Research Center. Dr. Lahav has a long history of avocado research

conducting work on plant nutrition, irrigation management as well as scion evaluation. He spent a 1

year sabbatical with Dr. Bob Bergh in the early 1990’s and assisted in the transition of the California

breeding program when Dr. Arpaia took over the current program. In spite of being retired, Dr. Lahav

remains active in the scion breeding program in Israel. Together with Dr. Uri Lavi he wrote the chapter on

Breeding and Genetics in Volume 2 of the Avocado edited by Schaffer, Whiley and Wolstenholme.

Hi Reuben, I don’t think the cultivar breeding program should be reduced. There is no commercial fruit type without cultivar breeding program. All the “stories” about the difficulties and long time [and money] required are true. However, look what happened to the California [and world] avocado industry when the ‘Fuerte’ was replaced by ‘Hass’. No better example is required. Therefore, I don’t think the objectives and budget for both projects should be cut. On the other hand the option for combining the two projects should be checked. I don’t have enough information to go into details, but both projects are located in UCR and I am sure there are duplications in some aspects. I know it is complicated also because of personnel involvement but it might save money. Best regards Emi

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Dr. Uri Lavi is a retired researcher from the Volcani Agricultural Research Organization in Israel. He was

stationed at the Research Center in Bet Dagan. Dr. Lavi is a plant breeder and oversaw the mango and

avocado breeding programs in Israel for many years. He is very familiar with the program in California,

having visited UCR many times. In 2006 he and Dr. Jose Chaparro served as outside reviewers on the variety

breeding program at UCR. In spite of being retired, Dr. Lavi remains active in the area of genetics. Together

with Dr. Emi Lahav he wrote the chapter on Breeding and Genetics in Volume 2 of the Avocado edited by

Schaffer, Whiley and Wolstenholme.

Dear Reuben,

Thanks for sending me the various opinions.

With your permission, I would like to broaden the discussion and I am sorry (as usual…), if I play the “devil’s advocate”… I would like to refer to both the molecular approaches and to the classical breeding of avocado. Since many people have invested lots of efforts in these two areas for a number of decades, I would like to take this opportunity for some “Heshbon Nefesh” – self criticism. It should be quite clear that first of all, I am criticizing my activities.

First, the diagnosis: In spite of the major efforts invested in the molecular projects and in spite of the many achievements, I don’t think that there has been a major breakthrough and definitely not one that affects avocado breeding. Regarding classical breeding, again, in spite of the major efforts (mainly in CA and Israel) and in spite of several interesting new cultivars, I don’t think that there has been a major breakthrough in terms of a leading cultivar.

Molecular Approaches:

All of us were enthused in 1980 with David Botstien’s development of the RFLP and soon after that, the concept of Marker Assisted Selection (MAS). Since then, new kinds of markers and new concepts have been developed. However, to the best of my knowledge only a few examples of application of MAS do exist in practice. Such beautiful examples are limited to Mendelian genes such as the DNA markers for resistance to TMV, Verticillium and Fusarium which are used routinely in tomato breeding projects. I am not familiar with MAS used routinely in breeding projects of QTLs and definitely not in breeding projects of fruit trees. (It is true that there are some DNA markers for QTLs in plants but they are rather few and quite imprecise). Please note that the traits that avocado breeders are looking for are controlled by QTLs (as in many other plants).

In order to assess the situation let’s look at humans: (Please note that most DNA markers and mapping concepts were developed by human geneticists).

While breeders look for the “good genes” human geneticists look for the “bad genes”, namely the genes which when mutated, result in various diseases. The situation is similar to the above description in the sense that there are beautiful examples of identification of

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genes that “control” single gene’s diseases (such as Tay-Sachs; CF, FX and many more) but, there is limited success in identification of the genes controlling the complex diseases (Diabetes; Blood Pressure; Obesity and many others). Most of these limited successes have been achieved by Genome Wide Association Studies – GWAS, namely the phenotyping and genotyping of tens of thousands of individuals each one by 500,000-1Million SNPs. A striking example is human height: Height is the human trait with the highest value of Heritability and its phenotyping is easy and accurate. The point is that in-spite of genotyping and phenotyping tens of thousands of human individuals, only about 15% of the phenotyping variation can be explained by the SNPs identified in these GWAS. There are several explanations for this very bothering situation and I will not go into them here.

It is true that large plant progeny populations are advantageous to the human unrelated individuals described above. But, based on all the above should we not be more cautious regarding the potential of QTL mapping (of rather small populations with a rather small number of markers) to MAS in avocado breeding?

Please note that researchers were quite disappointed with the potential of DNA markers for MAS even before the SNP era. They then realized that to get this job done, there is a need for more markers (due to the rather short segments of Linkage Disequilibrium), and more individuals. The two major advantages of SNPs are: 1. they are very abundant in all genomes (there are about 20 Million human SNPs), of which one can routinely use 500,000-1M. 2. SNPs can be genotyped in a very high throughput (tens of thousands of human individuals).

In addition to the above, MAS in avocado seems to me to be quite distant because avocado breeding has (what I call) a “general goal”. Namely, we are looking for better cultivars in various traits (as opposed to “specific goal” such as seedless grapes, thorn less prickly-pear or peel-able citrus). Thus, I find it quite difficult for the breeder to apply MAS to avocado breeding even if and when, one or two markers to specific QTLs (which control say 20% of the trait variance) are identified.

One is interested in identifying the important QTLs not only for MAS. Identification of these genes and studying their control has for example, the potential to improve management procedures as well as the potential to be used in the future for the generation of transgenic plants.

Thus, a lot of research effort has been invested in identifying the important genes in various organisms mainly in humans. There are several molecular avenues to reach this goal, for example: GWAS (mentioned above); Analysis of the transcriptoms using the modern (NGS), technologies of sequencing and knock-out and knock-down technologies (RNAi and other tools).

It seems to me that the important genes in avocado will be identified mainly by homology with genes from other plants (whenever possible). Since avocado genome, is about 4

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times smaller than the human genome, due to the better segregating population available in avocado, and providing there are several tens of thousands of SNPs (I do not know the number of SNPs on the chips mentioned in the discussion), and several thousands of individuals, then GWAS are indeed a good option. In addition, I think that major research efforts should be invested in analyses of the transcriptoms of various avocado cultivars having different phenotypes of the same trait (such as fruit size, aroma, flavor, yield storage capacity and more). Such projects could be carried out without prior preparation of populations and need only careful thinking and planning. Even the cost of such projects is reasonable.

I also think that it would be very important to invest in the development of a regeneration procedure for avocado to be used in the future for knock down experiments and for the generation of transgenic plants.

Trying to refer to your specific question, I agree that one needs large populations for QTL mapping but as mentioned above, I doubt if that would be sufficient. On the other hand, I think that there are better options (see above).

Classical breeding:

The main reason, in my mind, for the lack of success in the generation of a leading cultivar, in our avocado classical breeding projects, is the rather low level of genetic variation that we use in these programs.

Please remember that we are mainly interested in QTLs, that the major variance components of these QTLs, are non-additive and that we are interested in better cultivars, namely, in combinations of several such QTLs.

Let me say in brackets that to make this story even more complex I would like to mention that years ago, we approached about 15 top experts of the avocado industry in Israel and asked them to “draw” (on paper), the ideal avocado in terms of fruit traits (such as size, shape, color etc.). The following will explain the output of that study: As opposed to Jose’s quotation: “opinions are like noses, everyone has one”, the saying in Israel is: “two Israelis, three opinions”…

The tools available to the classical fruit tree breeder in general and especially to the avocado breeder are very limited and even primitive.

I appreciate Mary-Lu’s statement about the quality of Gwen and Gwen’s offspring as parents. However, I do not know the exact statistics and to the best of my knowledge, none of those releases is indeed a leading cultivar.

Thus, I think that it is highly important to dramatically increase the genetic variation of the parents (serving either as mother parents in Ops or parents in controlled crosses). That

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means using not only the best cultivars as parents and also using as parents even trees from the various races.

Summary:

In spite of all the above, I am highly optimistic regarding the contribution of both the molecular approaches and the classical breeding to the advancement of the avocado industry.

Dr. Neena Mitter is a Senior Research Fellow with the Queensland Alliance for Agriculture and Food

Innovation (QAAFI) at the University of Queensland in St. Lucia, QLD, Australia. Dr. Mitter is currently

conducting research on the development of RNA silencing based Phytophthora root rot resistant avocado

rootstocks, somatic embryo regeneration in avocado and the development on new methods of clonal

propagation for avocado. Her work is funded by the Australian avocado growers.

Hi Reuben, I am fully supportive of the avocado breeding program and its value to the avocado industry. It is a very valuable resource that needs nurturing if we have to make avocado the stand out wonderful fruit and meet the demands of the consumers. Kind Regards Neena Neena Mitter Senior Research Fellow Queensland Alliance for Agriculture and Food Innovation (QAAFI) Level 4, Ritchie Building (# 64 C ) The University of Queensland, St Lucia 4072

Dr. Fernando Pliego Alfaro is a researcher in the Dpto. Biología vegetal (Fisiología) at the University of

Málaga, Spain. Dr. Pliego Alfaro has 30+ years experience with avocado. He is currently overseeing the

rootstock program in Spain looking for Rosellinia resistance as well as overseeing a research program

focused on the regeneration of avocado from tissue culture.

Dear Reuben,

Attached, please find some comments and I do hope you find them useful.

It seems reasonable and well justified that rootstock breeding, mainly related with root rot tolerance and salinity should be a priority.

It is nonsense to ramp down the scion breeding programme. Stopping the scion programme in a woody plant such as avocado with such a long juvenile period will take many years for recovery, in such a way that, closing it, would leave California growers out of the path for many years. The decision taken today will have implications 20-30 years later. Avocado is an interesting crop in the sense that Hass is the dominant cultivar all around the world, however, this situation will not last forever. New cultivars, with new traits will be needed to satisfy consumers in the future. These new selections could be giving California growers (in 20-30 years) an advantage in comparison to other countries with lower production costs and which do not have and are not planning to have a scion selection programme. Along this line, the availability of the avocado genome with growing information provided by new and more powerful molecular markers could considerably speed up breeding, assuring the outcome of interesting selections.

Concerning project leadership, a person with conventional breeding background and horticultural training could be the project leader, although this person should be in close contact with a group with strong background in molecular breeding techniques. Along this line it is necessary to take into account that molecular data should go along with correct phenotyping and evaluation of germplasm collections.

Taking into account the importance of root rot, rootstock selection for pathogen tolerance should be addressed by a plant pathologist as it has been so far. Advanced selections should be given to the scion breeder who would be in charge of screening and selecting them for salt tolerance. Hence, the scion breeder should open a new research line on rootstock breeding for salinity tolerance. At this point, the group with expertise in molecular tools could help both, the pathologist and the conventional breeder, in application of these techniques to speed up the breeding programme.

Some of the problems indicated in the document are common to other countries; hence international collaboration should be reinforced, perhaps, sharing costs when addressing common goals will be the solution.

Well Reuben, good luck and if I can be of any further help, please, let me know.

All the best to you

Fernando

Dr. Zelda Van Rooyen received her PhD from the University of Pietermaritzburg in Kwazulu‐Natal and is

currently the Research Manager for Westfalia Technological Services (WTS). In this capacity she

oversees the activities of WTS in avocado rootstock selection and evaluation as well as scion evaluation

and postharvest studies.

Hi Reuben,

Attached please find my comments in response to the recent CAC document you sent me regarding the

future strategy of the avocado plant breeding programs.

It is my personal opinion that the closure of the variety program will be a great loss to the international

avocado industry. It has been an absolute privilege to work with some of the breeders from UCR in my

short career and to realise that the South African avocado industry exists today because we have stood

on the shoulders of giants who were fearless in their pursuit of the perfect avocado.

Regards,

Zelda

Zelda van Rooyen Research Manager, WTS

Website:

www.westfalia.co.za

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Zelda van Rooyen: Research Manager, WTS, July 2013

between rootstock and fruiting variety in terms of productivity and thus having both components in one program is beneficial and saves evaluation time.

4) I would not recommend moving the whole Genetic breeding program to Miami‐Dade, Florida. In terms of phenotypic gene expression California is more similar in climate (specifically cold) and cultural practices (e.g. root rot conditions, variety spread) to the other important avocado producing countries in the world (e.g. Chile, Peru, and even South Africa) than Florida is. Further West Indian varieties are not currently the most commercially profitable fruit sold around the avocado world.

5) I support the idea of securing (and testing) avocado genetic material at multiple sites, and I further support the development of large mapping populations provided a standard evaluation used and overseen by the same person.

6) In terms of fruiting variety trials I concur that trials must be planted either in different geographic areas or under different environmental conditions. There is much research to show how significant an effect growing conditions play in productivity and fruit size (to name a few).

7) With regard to scaling down of the scion breeding program I am of the opinion that this is very short sighted, and a huge disservice to the success of this program over the last few decades, and the future of the avocado industry around the world. The UCR scion variety breeding program is the best in the world, if not the only one of its kind. Some of the successful varieties from this program include the Gem® avocado which has made a significant contribution to the South African supply season and is slowly starting to increase in commercial plantings, and interest, in other countries. It is true that there have been many Hass‐like cultivars released previously, and that the season can be extended by other greenskin varieties, however there is a wealth of evidence to show that many of the existing cultivars have certain shortcomings which makes the search for better, more robust cultivars more appealing and necessary. For example, the Lamb Hass variety, while being later to mature than Hass is prone to significant alternate bearing patterns. The variety tends to colour up while still on the tree, and this makes exporting the variety more difficult. Further the variety does not ripen at the same firmness as regular Hass and thus many ripening programs prefer not to work with this cultivar. Worldwide there is a trend towards selling avocado fruit as “ready to eat” and thus ripeners want to work with fruit that are easy to manage. Gem® on the other hand is a very attractive fruit, ripens similarly to Hass, eats fantastically, and bears as good or better than Hass in most cases. It is unfortunate that there are not bigger plantings of this fantastic cultivar in California itself. In South Africa the Gem® is managed in a Grower Club under which the area allowed to be planted was initially limited. This was the first avocado Grower Club established in South Africa and today growers see the value of paying a royalty for the right to plant this variety as it truly adds value to their farming operation at the end of the season. The variety is compact, lending itself to higher densities, produces fruit on the inside of the canopy and thus results in a higher percentage of first grade fruit. Further the fruit are slightly larger than Hass, and the variety has a very low alternate bearing index. It is my opinion that growers across the globe will soon be comfortable with the concept of paying a royalty for varieties which have a proven record of higher production, yield efficiency, postharvest quality and established seasonality which allows the grower to target his market according to his personal climatic and cultural conditions. From a South African point of view, a large percentage of our exports go to the UK/Europe. In the UK, especially, there is an increasing demand for unique varieties, of excellent eating quality but which are physically different to standard commercial varieties. While these varieties are mostly used as a marketing tool it is interesting to note that customers are not afraid to buy and try these “weird and wonderful” varieties, and makes one wonder whether the avocado industry, in general, has not underestimated our customers. Customers in the UK are actually prepared to pay more for round, green avocados than for Hass fruit. If we are honest, we have become a little complacent and easily hide behind the fact that Hass‐like cultivars (which blacken on ripening) more often than not hide handling errors made between the orchard and retail outlet. I’m afraid that this will be become more difficult as consumers around the world become used to having avocado fruit on the shelves for 12 months of the year, and will soon be able to discern between fruit of inferior quality. In many countries the avocado was previously considered to be a luxury item however, now statistics show us that the consumer is not only prepared to pay more for this fruit, but that they actually want it “ripe and ready to eat” and that they are willing to pay more for fruit of superior quality. Furthermore, the farmer of today is more often than not an University graduate who is not afraid to use mechanization and computerization to improve the efficiencies of his/her framing operation. Agricultural land is becoming expensive, labour costs are high, as well as water and electricity. The

3


new generation of farmer is therefore more interested in learning about rootstocks and cultivars, that while more expensive to buy, will yield better and for longer, with easier management inputs. Packhouses can, and do, run for 12 months of the year to decrease overhead costs. Consumers want fruit for 12 months of the year. Growers want to utilize their labour and operation costs. The simple solution is to plant a number of different fruiting scions that will stretch the harvesting season. A wider spread of fruiting varieties on a farm can also decrease the risk of the farmer as hot or cold spells experience at the “wrong” time can have deleterious effects to flowering and fruit set during the season. However, the grower needs to have a selection of varieties to choose from that will suite his climatic conditions the best. If he is located in a cold are where the minimum temperatures in winter go below +4oC he/she does not want to plant West Indian varieties. Similarly if he is located in an area where conditions are hot and windy during flowering and fruit set he/she does not want to have a monoculture of the Hass variety. Farming with avocado’s is a science and growers want high yields, less disease, lower production costs and less alternate bearing. Thus, to summarize: if the UCR avocado variety breeding program were to be scaled back/stopped the industry could find themselves in a situation in 10 years’ time where the consumer demands have changed, as well as the climactic conditions under which avocados were previously grown. It is unlikely that new varieties will easily come from the private sector as growers do not have the capacity, or know how, of how to test varieties for true yielding capacity, postharvest quality and storage sensitivities. To properly test a variety you need a team who can (1) graft the trees and plant them in different geographic conditions; (2) Who can test the postharvest quality and prevalence of postharvest disease or physiological disorders; (3) Who can store fruit and conduct organoleptic test; (4) Who can, in short, test the commercial potential of a variety. In South Africa there are is a recent example where a private breeder released a variety within a few years of observing an interesting tree – and which was soon found to cost the industry thousands of dollars to fund research aimed at solving postharvest disorders and shelf life problems which would have been identified had the variety undergone proper testing as currently conducted in the UCR breeding program. Should the fruiting scion breeding program come to an end I would still recommend that selections from external sources be evaluated at the least.

8) Regarding the proposed benchmarks and performance measures (pg 4). The delivery of a new variety every seven years is impossible, or rather very dangerous, to do if it is meant that from planting the seed to commercialization must take seven years. A responsible breeder would need to conduct trials to determine postharvest fruit quality, and perhaps even storage trials, to determine the true commercial potential of a variety. In Westfalia’s experience some cultivars are great for the local market but do not ship well, (which requires cold storage for 21‐28 days), and often develop chilling injury or various physiological disorders. Further, a breeder needs to test how long fruit can hang on the tree before disorders start to occur (if any), and they need to collect yield data over a few years to determine the alternate bearing index. When seeds are planted it takes a while for trees to become mature enough to bear fruit. The body/person applying for the Worldwide rights would not easily take on a new cultivar if proper yield, cultural and postharvest data had not been collected.

9) Regarding using genetic tools to enhance, shorten the breeding program. I agree that this technology is still in the development phase and that we still have a road to walk before “genetically modified organisms/cultivars” are accepted. However, this technology is very exciting and progress is being made every day.

10) Regarding the commercialization costs of a new fruiting variety. It is true that these costs are higher than those needed for new rootstocks, and that acceptance of a new fruiting variety can take longer. However, if comprehensive tests have been conducted on the variety during the screening process it would take less time to convince a potential Master License Holder (MLH) to purchase the rights to a cultivar. The onus would then be on the MLH to do the necessary marketing of the variety and to get growers to test the variety under their growing conditions. [In the case of Westfalia, we are lucky that we are a vertically integrated company and that we are involved from the making of trees, to producing fruit, packing fruit and even marketing fruit. Our customers, specifically in the UK, expect only the best quality fruit, and are prepared to pay for that right]. If the Californian industry does not have an appetite for developing new varieties they should be assured that the rest of the world is. This is not only relevant to more discerning customers, but also to growers who wish to produce avocados in slightly marginal areas, and who don’t necessarily have the right conditions to produce high yields. The Hass variety, for example, is sensitive to stress and can often yield poorly if conditions are too hot or too cold. While rootstocks can improve matters to an extent it is often found that

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alternate varieties are needed to increase the yield/hectare. Furthermore, the first two avocado Grower Clubs have been established in South Africa and growers have been very happy with their first commercial returns on their initial investment(s) in the new varieties.

11) Regarding the Timeline needed to release new varieties. This kind of research program is indeed long term, and it is preferable to have a low staff turnover with a stable research environment. This is especially true if external funding is needed, or international collaboration is to be encouraged. Westfalia has its own rootstock breeding program and we have had a long standing relationship with the UCR breeding programs in the past (both fruiting variety and rootstock). In terms of the exchange of rootstock material for testing, however, it has been a little unsettling in the last few years to have the person responsible for the evaluations keep changing requiring new relationships to be built and experience gained. As breeders ourselves we would place more confidence and value into a program that was considered “solid”, and be more willing to exchange new material. I’m sure this would hold true for external investors as well.

Lastly, it is my hope that the Californian Avocado Committee would reconsider the long term implications of stopping the scion variety breeding program. Perhaps the merging of the rootstock and fruiting variety programs would help save costs in the short term to allow for further investigations as to the consequences. As more fruit grown outside of America enters the country more pressure will be placed on American growers to remain competitive, and this will necessitate the ability to produce fruit at optimum tonnages, and of a high quality. One should always remember that the customer is king and that he wants more bang for his buck! Regards, Zelda

Avocado Plant Breeding Strategy Draft ‐ COMMENTS

Avocado Plant Breeding Strategy 2013‐2033 (Draft) Dr. Jonathan Dixon, CAC

Comments made directly on draft document by Reuben Hofshi, Dr. Jose Chaparro and Dr. Alon Samach

Dr. Jose Chaparro is a stone fruit and citrus breeder for the University of Florida. He has participated in the last 2 Avocado Brainstorming meetings as well as a member of the audit team of the avocado variety program in 2006.

Dr. Alon Samach is a faculty member at The Hebrew University of Jerusalem in Rehovot, Israel. He is well known for his work on alternate bearing in various plant species. He recently wrote an extensive review on this subject with Harley Smith.

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Original TEXT Hofshi Chaparro Samach Are new Rootstocks or Varieties needed? The CAC Board meeting of 30 May 2013 included a strategic discussion on marketing, industry issues and research. The discussion was the culmination of a series of strategic evaluations during the past two to three CAC Board meetings. The role of new varieties and their place in the future of the California avocado industry has been an integral part of the consideration for the California avocado industry activity in the future. A large part of the future appears to be based on diversification of California avocados in either image or varietal types (or both) that result in longer marketing window and competitive advantage for California growers. The Board discussion seemed to conclude that many of our existing varieties provide the necessary traits and maturity dates to achieve the diversification needs of the industry. The Board also concluded that development of new rootstocks that provide solutions for root rot and salinity/chloride issues is an urgent industry issue. The net result of the strategic discussion is there is the most support for breeding new rootstocks to solve production issues and less support to breed new fruit types to realize marketing opportunities.

Overall comments: This document continually mixes varieties with rootstocks and it is often times difficult to discern what is being commented about. Either there should be 2 separate documents or the comments/analysis should be broken into 2 separate sections (varieties, rootstocks) with a third section discussing where the 2 programs can/should overlap. Sentence 5: Which are these many varieties? Sentence 6: I don’t recall this great push for rootstocks at the CAC meeting. A statement that existing varieties already allow for the diversification of what the industry needs a more complete evaluation of what time period and when is the prime quality of these “replacement” varieties. Any effort in filling California marketing voids needs to be done with material that is being harvested at optimum quality. Historically, varieties such as Zutano and Bacon, were harvested prior to optimum quality to fill market demand. Even before the advent of Hass dominant industry the CA industry did not have 12 month presence in the US market.

Sentence 5: What does this mean? This is for existing needs, what about needs that may arise in the future?

New fruit types were not considered a high priority for breeding but there was strong support for using existing non‐Hass avocado varieties, e.g. Reed, GEM, Gwen and others, to diversify the California avocado industry for year round California avocado supply. These existing non‐Hass fruit varieties have their own unique harvest windows and quality attributes

Sentence 1: No scion breeding Sentence 4: Say you don’t want scion breeding, The Reed, GEM and Gwen mix will not give 12 month presence in the market. Rootstock alone will not give salt tolerance. The response to salinity and other environmental stresses will be a combination of rootstock and scion

The short term objective of diversification is good. However, it is narrow minded (short sighted) to think that the existing varieties will fulfill all the needs that will arise over time. In time flaws will be detected in these varieties and replacement cultivars will be needed to fill the vacuum. These flaws can be traits that were overlooked and changes in consumer

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and are under‐utilized due to low acreage, the volume of fruit supply and promotion support. The need for new fruit types was determined to be less urgent than the need to solve the immediate production issues such as salt management. From the Board meeting the general consensus was that the emphasis of the breeding program should be on new rootstocks and evaluation of existing non‐Hass varieties.

interactions. preference, or susceptibility to new pathogen strains or insects. Regardless, it is essential that the scion breeding program be continued to provide a source of new and improved cultivars.

Rootstocks or New fruit types? Commercial avocado groves consist of grafted trees where two different cultivars are used; a rootstock for a root system with special traits and the top a scion that bears the fruit. Currently at UC, Riverside there are two plant breeding programs, one for root rot resistant root stocks being run out of the plant Pathology Department at UC, Riverside and one for new fruit types and evaluation of rootstocks with the Botany and Plant Sciences Department at UC, Riverside. It would appear that there is overlap between the two programs as it is necessary to additionally test rootstocks as grafted trees and that the two programs could be combined under the supervision of a plant breeder.

Last sentence: How does testing compatibility and rootstock effect on scion makes it overlap that requires a breeder? In the last 40 years the only plant breeder at UCR was Bob Bergh. He collaborated with G. Zentmyer throughout his career. A plant breeder is a term reflecting someone who is doing plant improvement.

This is not overlap. What good is a rootstock that is incompatible with most scion varieties? Scion/rootstock compatibility IS AN ESSENTIAL TRAIT that needs to be evaluated in any rootstock breeding program for any crop. The product being produced is fruit not roots! Separation of the rootstock and scion breeding allows the breeders to focus on the improvement of their respective objectives, fruit quality and soil and water quality adaptation/pest resistance.

There appears to be two very well defined traits associated with the breeding of rootstocks identified by industry stakeholders: resistance to soil borne diseases and poor water quality due to salinity. There are other traits such as drought tolerance and a dwarfing growth habit that would be desirable but trying to achieve four traits would likely decrease the chance of successfully creating a new rootstock to be very low.

There is more than one soil disease; Thomas is good for one and not the other. A key point missing here is Productivity. The release of G755 is a great example where we had a rootstock well adapted to environmental conditions (root rot) but failed due to productivity. We must have rootstocks that are adapted, and there may be different rootstocks for different environmental conditions; but these rootstocks also must be productive with any scion variety grafted onto them.

Current and past plant breeding activity

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funded by CAC

Total CAC funding from 2002 to 2012 on breeding root rot resistant rootstocks, new varieties and genetics has been close to $3,762,000*. The amount of funding can be broken down to:

Does this include the 125K Mike Clegg got from the UC Discovery grant?

Root rot resistant rootstocks: $1,410,000 New varieties: $1,590,000

Genetics: $762,000

*The funding only includes the root rot resistant rootstock breeding project, the scion breeding project and the Clegg project on development of molecular markers and mapping population maintenance.

CAC funding in 2012‐2013 CAC fiscal year for the

rootstock breeding project: $150,000

scion breeding project: $211,354

What all is in this number?

variety and mapping population project: $19,126

Is this the top working project

Total: $380,480

Status of Current Plant Breeding research projects

Root rot resistant rootstocks Primary Investigator: None (Temporary: Dr Akif Eskalen, Former: Dr Greg Douhan)

Objectives: To breed a rootstock that is resistant to Phytophthora cinnamomi. The research proposal submitted in June 2013 also has an objective of screening the rootstocks for salinity.

How about citricola collar rot?

Activity: Evaluation of seedlings exposed to Phytophthora cinnamomi and planned salinity to select for root rot tolerance,

You could have had more if Harley Smith who is a very competent young scientist was still at UCR working on avocados. CAC was unwilling to support him when

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planting of selections at UCR or South Coast Research and Extension Center in Irvine (SCRES) and propagation of selections for planting on growers properties. Some analysis of the population genetics of Phytophthora cinnamomi strains in California.

called upon.

New varieties Primary Investigator: Dr Mary Lu Arpaia Objectives: To breed new varieties with higher productivity, lower alternate bearing, large sized fruit, consistent ripening during the season and are comparable with Hass for eating quality and postharvest storage quality. To assess rootstock scion interactions, evaluate and exchange promising new varieties from around the world and to maintain an avocado germplasm collection.

Activity: Evaluation of seedlings selected from crosses between different varieties, increased numbers of selections at SCRES and then on growers properties. Evaluation of new fruit varieties grafted onto rootstocks planted in field trials, some on growers’ properties. Taste testing of new fruit varieties. Evaluation of avocado cultivars sourced from other avocado plant breeding and evaluation programs. Germplasm maintenance of avocado varieties at SCRES.

See Uri’s comments about the need for a great number of genotypes. There has been no interest in evaluation of these “new” varieties by CAC.

Genetics Primary Investigator: Dr Mary Lu Arpaia Objectives: To utilize the UC, Riverside mapping population to resequence the population to identify more markers associated with desirable traits to use in marker assisted selection of seedlings.

Activity: Map phenological traits using genetic technology to use as markers for selecting seedlings using a small population of Gwen crosses.

The USDA lab has sequenced the Clegg collection using their SNP chip, data has not yet been provided but given this effort we should invest in collecting the

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Collaboration with USDA NGR (National Germplasm Repository) Miami‐Dade, Florida.

phenotypic data as proposed by Arpaia, otherwise we are wasting a real opportunity.

Summary of Plant Breeding program status

Our current program has partial alignment with the conclusions of the CAC Board and do not adequately address that the emphasis of the plant breeding program should be on rootstocks for salt tolerance and root rot resistance. The genetics effort at UC Riverside is limited compared to the significantly greater genetics research being conducted by the USDA at Miami‐Dade, Florida. For example the mapping population of trees used at UCR is 200 trees at two sites of Gwen crosses compared to two populations of 750 trees each of West Indian, Guatemalan and Mexican crosses. The USDA is sharing their much more detailed genetic maps with the Mexican researcher to help complete the avocado genome. It is clear that the plant breeding projects could be more integrated and focused into a single project.

It is not clear that the program should be placed into a single project. The Clegg effort in the past was the leading project worldwide until the development of the use of the SNP chip by USDA, which by the way is now considered a limited and antiquated approach. The approximately 5000 markers on the SNP chip is still just a small fraction of the size of the avocado genome. Some would argue that having 2 populations of the same genotypes allows one to see phenotypic responses and if you look at the Clegg work you do see that for some of the phytonutrients. Which one is better is a contentious point… it depends on your perspective. The point however is that there has been a lot of data collected already from the Clegg population and a lot more could still be collected. Additionally the germplasm in these plantings are more closely aligned with the material currently being used in the variety program. The USDA plantings initially were 750 plants. They have been seriously challenged by freezes and the ambrosia beetle. Phenotypic data is the crucial piece of information that we need, growing these trees in Florida will not provide useful information for the California grower. As for the Mexican genome project, this information is not freely available to the best of my knowledge.

Lines 10-11: These two populations represent initial studies into the genetics of commercial traits in avocado. They do not represent the majority of the commercial germplasm and are unlikely to identify the majority of the loci controlling commercially important traits in avocado. Research in this area should not restricted but rather expanded into additional genotypes from the UCR breeding program.

Proposed plant breeding activity Nowhere in the document does J. Dixon really say what is wrong with the current programs. His goals are a rehash of what

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researchers, the Genetics subcommittee and others have been saying for at least 20 years.

1. Place rootstock breeding, breeding of new fruit types and genetics under one project and request a proposal for a plant breeding program where the goals and traits are defined.

Having rootstocks and varieties under 1 umbrella, presumably under 1 person is not a good idea. There needs, in my opinion, to be 2 team leaders, one based in genetics and one based in knowledge of the crop. These two would build a team to oversee the entire project. It seems that in the past the goals of the respective programs have been well defined. The previous Genetics subcommittee was effective in communicating the needs of the industry to researchers the PRC and CAC

I do not see any benefit in putting the three programs under one project. I see disadvantages in that each one of the programs deserves full attention of a group, and that there is a limit to what one group of people can achieve. The group in charge of finding molecular markers that segregate with important traits (like P. cinnamomi resistance) requires expertise in genetics and molecular biology, and should be led by someone that has such expertise. I do not think that the leader of the two other projects should necessarily be an experienced plant breeder. Clearly a breeder should be part of the team, but the amount of breeding decisions made in a 10 year Avocado program are very little compared to a 10 year tomato breeding program. The main work during these 10 years is on Phenotyping and I would think that the best leader would be someone that is very familiar with Avocado and has experience in leading a group of people with different expertise. Again, the input from an experienced breeder is essential but his/her decisions will last for 5 years. Clearly the three programs should be talking to each other. Especially the program for finding markers should be making use of the genetic variability produced by the different programs, and checking their markers on the available germplasm. Regarding the need for a program on new avocado varieties, this is a tricky subject. The fact is that there were many programs and still the main variety grown all over the world was identified by a postman. I assume that over the years there were many breeding programs around the world were much money was wasted. It is easy to pay a technician (or several technicians)

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to walk among trees and fill charts and then have lots of charts and data and still no better variety than Hass. The selection process should be very proactive and here the expertise of a breeder in teaching the crew how to start from huge numbers and focus on select lines is very Important. I think that a breeding program needs to be continued but clearly it should be led by someone young with a lot of energy and ability to focus on an objective and not get lost in piles of numbers.

2. The strategy to pursue is to solve long term problems.

What are the long-term problems? You need to have both short term and long term objectives.

3. Proposed goal: To create an avocado root stock that is resistant to root rot caused by Phytophthora cinnamomi and is tolerant to salts up to xxx TDS and chlorides up to xxx ppm that is easy to propagate and compatible with a wide range of fruit types.

Here is only mentioned “rootstocks” but under (1) it is written “fruit types”. Surely the industry will need more than 1 rootstock. Other successful fruit industries employ a suite of rootstocks depending on conditions.

4. Traits desired: Phytophthora cinnamomi resistant This has always been the primary goal of

the rootstock program. But we also want to include other soil and trunk diseases.

Salt tolerant to xxx TDS – value to be determined

The UC asked for $ for this in the past and CAC has indeed funded research going back to the 1980’s. Oster, Crowley, Mickelbart etc. There was little interest in the VC material that Arpaia brought from Israel in 2000.

Chloride tolerant to xxxx ppm – value to be determined

Same comment

Easy to propagate What does this mean? If you have the perfect rootstock the ease could be just a technique or hormone concentration temperature and humidity control.

Compatible with all scion varieties This is a major undertaking and a project on to itself.

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5. Engage a trained plant breeder as program leader for a team of specialists that includes plant pathologists, entomologists, soil scientists, plant physiologists and horticulturalists.

Why does a breeder need to be the leader? Unless this person knows about avocados he will be hard pressed to assimilate information.

The program leader does not need to be a plant breeder as long as it is clear that THE OBJECTIVE IS THE RELEASE OF IMPROVED SCION AND ROOTSTOCK CULTIVARS.

Recent advances in technology for plant breeding has increased the chances of being able to develop new cultivars with highly desirable traits. However, along with better technology has come a greater degree of sophistication and knowledge needed to achieve the creation of new cultivars. Ideally a plant breeding program should have a team of experts who each contribute in their area of expertise and a leader who can co‐ordinate genetics and plant breeding activities. The best leader for a plant breeding program is an expert trained in plant breeding who also has a strong working knowledge of the genetics and how it can be used to advance the program and make it more efficient. For this reason a program leader trained in plant breeding is recommended.

See Uri Lavi’s comments. What training a plant breeder goes through at the university level? A breeder will not necessarily be a good program manager. How? The avocado community is still at the infancy of having useable markers. Many desirable traits are controlled by more than 1 gene. I agree we need to have a team approach and more integration is needed but does Jonathan know that this has been worked on before? A plant breeder per se is not going to make the program more efficient overnight. This will take many years and the program needs to continue to advance during that time. He needs to spell out what he thinks a plant breeder will add to the current program that is missing.

6. Develop a formal partnership with UC, Riverside and USDA ARS to manage intellectual property rights.

7. Preserve the existing germplasm as a resource for genetic studies. To secure the germplasm from disease and pest threats multiple sites should be established along with multiple copies of varieties as a source of budwood for rapid increase in tree numbers. Support the development of large mapping populations for the elucidation of the genetic

See Uri Lavi’s comments. Who will pay for maintaining the germplasm preservation? In the 1960’s/70’s the industry established germplasm blocks throughout the state. However they found that they could not be managed adequately and ultimately everything was moved to UC South Coast. (See Platt comments in the 1970’s CAS yearbooks). We haven’t funded collecting phenotypic data of the mapping populations we have already; are we going to invest more?

10


basis of traits. It would not be a bad idea to have multiple sites; but this will be VERY EXPENSIVE.

8. Create three sites within the south, mid and north avocado growing regions where the horticultural performance of varieties can be measured. This information will be used to establish the reasons for using the new varieties.

Isn’t this what we have now? Who will pay for this? Which rootstocks the new varieties will be grafted on. Both of the current programs have multiple test sites doing exactly this.

9. Ramp down the scion breeding program by stopping all new propagation, seed collecting and planting of advanced selections. Complete the evaluation of advanced material in tier 3 plantings and stop advancing material from tier 1 to tier 2 to tier 3.

If we had a suite of “perfect” varieties this would be all right, but we don’t. The old varieties that he wants to revisit all have some sort of problem. We need to do better than the old although I will admit for niche marketing some of the higher quality old varieties such as GWEN, Sharwil, etc. should be revisited.

This should not happen under any circumstances!!!!. The current effort of 1,000 - 2,000 seedlings/year is the minimum size needed to allow for selection pressure using the current breeding model. If CAC withdraws funding, an external source of funding should be identified to ensure continuation of the breeding effort.

10. Seek CAC Board approval for the release of new varieties and include a request for funding of the commercial development.

What about Zelda Van Rooyen’s idea to collect royalties to defray these costs?

Benchmarks and Performance Measures Evaluate progress every 5 to 7

years with option to change the investment.

You will learn little in 5-7 years, give examples of what you will evaluate.

The delivery of 1‐2 new varieties every seven years.

What will be developed in seven years? Surely not tested by any means? This is UNREALISTIC for either given the long turn around and field testing that is needed. Even the poster child of tree fruit, peaches and nectarines are 8 to 10 years. By “varieties” are we talking new cultivars or rootstocks?

I believe this to be naïve. It is too few if you are looking at a fully operational scion breeding program and too many if you are looking at a rootstock breeding effort. The evaluation of rootstocks is a long term endeavor. It requires a long period of time to test for yield, fruit quality, and incompatibility in rootstocks. Breeding is a long term investment that pays off. How many fruit tree scion/rootstock have been released as a result of biotech vs. traditional breeding in the last 25 years? What is the return on $ invested?

For any research program good oversight is essential to ensure the program maintains its focus on the desired

Why do it at all then. If you are not convinced that the industry needs a variety breeding program. See Emi Lahav’s

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outcomes. This is more important for the long‐term projects conducted over decades where there are personnel changes. At an investment of $500,000 per year a review after the fifth year would represent spending of $2,500,000 and be at a point where sufficient activity had happened in the program for probable success to be evaluated. At the review the program would be re‐evaluated as to meeting the objectives of the program could involve options to disinvest or increase the investment in plant breeding.

comments about fruit industries. The industry should reinstitute the Genetics Subcommittee which was very effective and provided excellent input to the UC researchers.

Proposed Funding Required The funding required to generate new avocado varieties, based on how much CAC has provided in past years, indicates the creation of 2‐3 new avocado cultivars is likely to cost $5,000,000 to $7,500,000 over 15 years. This is an annual spend of around $330,000 to $500,000. Outreach and the development of a commercial market for 2‐3 new avocado cultivars will need to be aggressively pursued to create the critical mass necessary for sufficient production volumes to meet potential consumer demand. This activity could cost a further $2,500,000‐$5,000,000 over an additional 10 year development time. This would be an additional $250,000 to $500,000 annually of non‐production research funding support. These estimates are optimistic as developing and introducing new avocado cultivars has taken a minimum of 20 years or more with minimal investment in market development.

Cost is secondary to the decision to commit to a program; you either do it or not. Jonathan is mentioning varieties here. I assume fruit types even though he has said to ramp down? He is correct about the lack of investment to build interest in the varieties that have been released previously.

The investment in plant breeding needs to meet the desirable outcomes set by the objectives. The funding is likely to be an increase from the current spending of

Everything costs more including water, fertilizers and labor. $500/ acre foot water at South Coast REC still is relatively inexpensive,

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about $380,000 per year to allow for increased effort in genetics research and commercialization. The suggested level of funding annually is $500,000, a 30% increase over current spending. New technology in the form of genetic research is now available but is expensive and low yielding. There has been considerable inflation in the costs of plant breeding over recent years that appears difficult to control as additional costs are coming from outside sources. In addition, sufficient information needs to be collected on the cultural management aspects of new cultivars to allow the development of an investment case. This is a budget sufficiently large enough to allow diverse activity but not so large that the Commission will have to reduce its efforts in other areas of research. However, this investment will only work if the plant breeding program is rationalized and a comprehensive project plan is developed by a program leader, preferably a plant breeder, that integrates traditional plant breeding and new technology along with generating the information needed for market development and cultural management.

A long list of wishful thinking. Are we talking here about varieties or rootstock? Is he suggesting that the commercialization costs also come out of the PRC budget. It should come from the marketing budget. He again harps on it needing to be a “plant breeder”. What is most important in my view is to have someone (I would say have 2 program leaders) who has an excellent understanding of the avocado, the industry and their needs.

The tools to improve the plant breeding process that show the most promise are the new genetic technologies. Unfortunately, the genetic tools are still in a development phase and are likely to take many years before significant gains in efficiency are made within the plant breeding program. It will take time to identify the genes of interest associated with specific traits and how their manipulation can be utilized in the development of new cultivars. The genetic work may allow the faster

See Uri Lavi’s comments, if we are years away from efficiency why are we calling it available tool? How did we get from the tool of genetic markers being SNP or QTL to genetically engineered?

This is not proven, traditional breeding has been releasing improved varieties since man started domesticating crops!

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development of new cultivars but there will remain an extended period of testing to be sure the traits are expressed in the field. A further unknown is the acceptability of genetically engineered or enhanced plants to the market.

Appendix 1. Background Hofshi Chaparro

Plant breeding Strategies Identified by Stakeholders

At present three strategies have been identified through consultation with stakeholders for breeding improved avocado varieties:

Who are these “stakeholders”?

A) Solve long‐term problems…… By creating new cultivars based on pest, disease and environmental resistance with adaptation to California soils and poor water quality while retaining the best characteristics of Hass…… To reduce cost of production to improve profitability and allow avocado production in marginal growing conditions

This is apparently for the variety yet soils and water quality. This is very confusing; this is talking about new varieties, not rootstocks.

Don't make the same mistake that the apple industry made with red delicious. There is always something better out there, short term use HASS, long term look for something better!

Current strategy followed by the root rot resistant rootstock breeding project.

B) Adapting to change by anticipating the market…… By creating new cultivars based on improving Hass to reduce production costs…… To maintain the current position in the market and developing a greater reputation for reliability and quality

Second point: What does this have to do with breeding? It is very confusing to be talking about new varieties and rootstocks interchangeably. .

This is not anticipating the market! Anticipating the market is determining what the consumer does not know he needs. Think out of the box. Ie the IPAD, look at this small computer that made the net book extinct in less than 4 years, and is having a significant effect on sales of laptops. Small seedless easy peeling tangerines not large monsters.

Not being followed in the plant breeding projects. What does this mean? To follow the breeding plan requires a clear statement on what is to be accomplished. The Genetics subcommittee in the recent past was the conduit for getting the information to the researchers. There is a lot of evaluation going on continuously including taste panels which always include Hass as the standard.

C) Create a new avocado market……

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By creating new cultivars based on taste and phytonutrient characteristics…… To corner the market in a new industry

Current strategy followed by the scion breeding projects.

The making of new varieties Jonathan Dixon jumps from rootstock to variety calling both the same “variety”. This is very confusing especially since earlier in the paper unequivocal statements were made that the board doesn’t consider new fruiting varieties important and should be ramped down.

In a traditional plant breeding system an example of the method used to breed new rootstocks is where seedlings are exposed to a challenge such as a disease or salty water (or both) and those seedlings that survive are selected for further testing. The selections are further tested against the disease or salty water and then ideally should be cross‐bred with other more tolerant selections and the resulting seedlings be placed through the same process. After field trials the new selections may be released for commercial use. A generalized diagram of the process is below. Each turn of the cycle is likely to take 5 to 7 years for a new rootstock and longer for a new fruit type.

Sentence 1: Where have they done the salinity breeding as described? Regarding generalized diagram: How many total turns are there in the diagram? Is this the sum of the squares? To do a field trial and get yield is 5 to 7 years alone much less the time needed to select the rootstock/cultivar etc. The evaluation of material needs to be very thorough and in a sequential order and will most likely will take 15 to 20 years.

For new fruit types the selection process can only occur after the fruit can be evaluated which requires several years. The most promising selections are then planted in field trials grafted onto standard rootstocks and evaluated for several more years before commercial release.

How does he propose to evaluate faster? The only thing I believe is to test for markers in an early stage. What if something potentially superior but does not confirm to the desired traits; is this to be discarded?

Genetic technology can be used to advance the selection of seedlings with desirable traits without the need for fruit to be present. Much greater numbers of seedlings can be evaluated without the need to plant and grow the trees until they fruit. This represents a saving in the space needed for evaluation but does not reduce the amount of time needed to evaluate new selections. Measuring the genetic components of the seedlings has an additional cost and first it will be necessary to identify the genetic basis of the traits of interest. This extra expense may be less than the cost of growing and maintaining new trees for several years.

Where is the cost analysis? All current evidence in other commodities suggest that this is a VERY RISKY approach. This would be nice but as we discussed, many traits are controlled by multiple genes. Markers can be used ideally to select seedlings with fatal flaws. How are we going to prioritize all the desirable traits which are likely controlled by more than one gene?

This requires that all the background work, generation of segregating populations, genotyping and QTL analysis has been done. However the fundamental problem here is are the traits essential? Use MAS only for essential traits.

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Generalized diagram of plant breeding process

Another option would be to genetically engineer new avocado trees but this, aside from any negative consumer perception that may occur, will require the technology to recover avocado trees from cell cultures and a detailed gene map associated with desirable traits which will take some considerable time and funding despite the avocado genome being available.

Correct

Testing new varieties

The amount of time to create and then test potential new varieties is not easy to define. Considerable testing can occur and the new variety fail commercially. The Thomas rootstock and the fruit varieties Gwen and GEM are examples. Long testing times increase the expense of plant breeding but are necessary to ensure good commercial performance. The best information available of the amount of time needed for new variety evaluation is from the rootstock project (see Table 1) where on average about 10 years of evaluation were required for those new rootstocks released for commercial use. A number of potentially valuable rootstocks remain under evaluation. It would be expected that new fruit varieties would have similar or longer evaluation times.

Pertaining to Gwen and Gem: I don’t see at all the failure of Gwen and GEM. GEM has been placed on the back burner (see Zelda Van Rooyen’s comments) and Gwen was mishandled at a tremendous cost to growers who could have benefited if the handling and the marketing had incentives. It is much easier to do nothing and let Hass take over the avocado world. Thomas and G755 were released prematurely because of growers’ pressure to have something better than the then current rootstock Duke 7. Last sentence: It is longer than 10 years to develop a rootstock. If anything it requires more testing to find deleterious attributes that can bring disappointment if and when they are determined to be unforeseen flaws.

Does this include the time used to initially screen the segregating population? This strikes me as an underestimate of the time?

Table 1. Rootstock evaluation for selections rated as highly tolerant to root rot.

Name Years Locations Salt tolerance

Root rot tolerance

Anita 8 20 T HTBrandon 5 15 S HTDusa* 19 40 HT HTEddie 6 12 T HTJohnson 7 6 T HTSteddom* 11 19 MT HTToro Canyon*

6 5 T HT

Uzi* 11 22 S HTVC207 8 10 HT TVC801 8 6 HT TZentmeyer* 12 30 S HT

I am not sure about the high salt tolerance and what about negative aspects such as drowning and vigor for Dusa? Where does the data for VC801 come from? Who analyzed the salinity aspect of all these rootstocks? Where is the data?

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Average 9.2 20 Range 5 to

19 5 to 40

S = sensitive, T = tolerant, HT = highly tolerant, * released for commercial use

Explaining the benefits of new varieties Is this rootstocks or cultivars? This section is not well organized. It appears that Jonathan is really writing about new cultivars and not rootstocks.

Choosing to invest in new varieties whether rootstocks or new fruit types involves risk for avocado growers and is a business decision that should result in an enhancement of the profitability of an avocado grove. To best evaluate the commercial reasons for planting new varieties the grower needs the following information which should be collected when a new variety is in the testing phase:

Sentence 1: I don’t see the link that mixes rootstock breeding with fruit varieties. There are overlaps but rigorous testing is required. Regarding profitability: How about sustainability, maybe there is enough to pay the overhead in the months when California Hass is absent. Last sentence: See Emi Lahav’s comments about fruit industries.

a. Income i. Yield ‐ tree age ii. Size profile of fruit iii. Quality ‐ tendency to blemish iv. Consistency of yield

b. Growing costs v. Amount of water needed vi. Salinity tolerance vii. Pest resistance viii. Disease resistance ix. Tree size and shape x. Nutrition needs xi. Ease of propagation

c. Marketing implications xii. Harvest season xiii. Acceptance xiv. Postharvest performance xv. Ripening characteristics xvi. Appearance

All these items are part of breeding and all these steps and more are necessary and in different environments, soil type and water quality.

Return on investment of solving long term problems is relatively easy to estimate where root rot resistance and salt tolerance has

Where is the data? Speculation is strictly an effort to sell the idea

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a very high potential to add 80 to 100 million pounds more fruit per year to the production of avocados in California. The savings to growers could be an estimated $30 million in lost fruit per year for root rot and potentially $40 million in lost fruit for high salinity irrigation water. These numbers would not necessarily be cumulative as both root rot and salty water often occur together.

Increased resistance to pests and diseases would lower the cost of production through the need to treat less with pesticides thereby increasing the sustainability of the industry. For example, avocado thrips has been estimated to cost the California avocado industry $5 million to $8 million dollars per year. Resistance to some pests difficult or too costly to treat may be the only possible way to have a commercial avocado industry in southern California.

Why does Jonathan think that some varieties are resistant to pests? Even Lamb, reputed to be resistant to some pests could be attacked by any pest depending on tree condition and the lack of other avocado trees as food source. Lamb is cold sensitive; assuming it meets all the criteria but fails because of cold tolerance then it failed the test and discarded?

An avocado fruit variety capable of good frost tolerance would extend the acreage where commercial avocado production is possible into areas where the cost of land and water is lower. Trees with characteristics of slow growth, dwarfing or fruit production off short branches would allow different planting and pruning systems to be used and have reduced labor costs for pruning and pest management thereby lowering costs and improving grove profitability.

The smaller the tree the greater the density what does he know about High density?

The value to growers of improving the Hass cultivar to be more productive and the fruit more robust with respect to postharvest handling and eating quality may be in maintaining a premium market position. There is potentially good value back to California avocado growers in achieving consistently good prices for a fruit already well known by consumers. How large this return to growers may be is unknown.

We are talking about fruit again. The goal of the industry is shifting, from a replacement of Hass by a better Hass into seasonality that will allow the CA brand to be present year round.

The successful commercialization of new or existing fruit types is likely to have high costs in creating a new avocado market which would need to be offset by higher values for the fruit than is possible in the current Hass dominated market. The potential of the market for different fruit types is difficult to estimate but could potentially be as great as the current California crop depending on the cultivar mix and retail outlets where the fruit are sold. The reason for the greater costs of introducing a new fruit cultivar compared to a new rootstock is a new market segment needs to be created. If new rootstocks are developed

This is all in the attributes and quality of the fruit. Being a breeding program of highly heterozygous fruit you will be narrowing the search using molecular tools. Commercial development could be done by handlers who will buy into the deal and also are pressured by the growers.

Not correct, “the consumer needs to be educated”

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there is no need to have an additional marketing effort to explain the new fruit type to consumers and retailers. Hence, a new fruit cultivar is likely to require funding for market development.

A new fruit variety and will also require a critical mass of plantings in order for there to be sufficient fruit volume to reliably supply a developing market. Partnerships between nurseries, handlers and retailers are necessary to push sales and to allow for returns from the new fruit to be sufficient to justify the risk and investment from growers forgoing the standard avocado variety. All this activity will require considerable and sustained outreach activity.

New variety is the strategic decision by the industry. Change is always risky and requires vision and will. Of course critical mass is important, but should we ignore the success of a small group of people to penetrate a niche market that can be propelled to greater numbers as the “test” show promise. You have to believe in what you are doing and not come up with obstacles

And this IS GOOD to ensure that the new variety has no flaws.

There are various ways to create a market for a new fruit cultivar, the most successful involve a programmed and controlled planting of limited acreage through licensing agreements and a well‐defined marketing channel for the fruit. This requires administrative support as well as an increased marketing investment. Simply putting the new cultivar out to the grower community and expecting a market to develop has not proven to be an effective way of creating a market for a new fruit cultivar. It is important that growers who invest in the new fruit are rewarded for their investment to pay for and encourage continued market development.

Okay

To breed new varieties successfully it will be necessary to define the desired characteristics of the new cultivars. If existing cultivars are used the differences in quality, cultural management, maturity standards and post‐harvest handling will need to be understood. This would require an extra research effort and along with the extra investment in marketing to create a new market is likely to be high and could at least double the total cost of fully developing the potential of a new cultivar. Historically non‐Hass varieties have had heavy price discounting impeding the development of a critical mass of supply. To avoid strongly negative economic signals working against creating a new avocado market it will be essential to work closely with a retailer and handler to ensure there is a suitable supply chain and marketing to achieve reasonable value for the fruit. Growers will need to be presented with a business case containing information to encourage investment in sufficient acreage to meet demand.

Sentence 1: Are we breeding again? Sentence 3: How does he know that? Sentence 6: As Bill Arterberry said he is throwing a stink bug into a perfume factory. Sentence 9: How are they going to do that at the moment they can only bring Hass. Sentence 10: Pure speculation. What does any of this has to do with old varieties?

If you don't do it someone else will, and you will lose market leadership.

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Additionally there will be a period of learning how to successfully grow each new cultivar. It may be possible that the supply of cultivars will need to be tightly managed and that considerable control over the marketing will need to be enforced. If this is not done then the benefits of a new cultivar may only be temporary as other non‐California suppliers come on stream or that the market for the cultivar becomes saturated quickly. Finally, care will be needed to avoid the expectation that there will be frequent changes in the cultivar mix as happens in the apple industry.

The commercial development of new varieties

Intellectual property rights

Develop a formal partnerships to manage intellectual property rights.

The California Avocado Commission is funding the breeding of new avocado varieties but has no control over avocado cultivars released by University of California, Riverside. The University owns the intellectual property rights to new avocado varieties and decides how they will be commercialized. The mechanism the University uses is a committee that considers if a new cultivar should be released without Commission representation. In addition, the University holds the patent rights to new cultivars and controls who has access to new cultivars. The USDA ARS has control over the genetic information on a number of traits and holds genetic maps. Access to those maps and requests to have mapping populations established that look for the traits of interest to California avocado growers would greatly benefit an avocado breeding program.

Sentence 2: In the last few years we elected not to negotiate a deal with UCR even though they left the door wide open. PRC is involved in supervising the quality research. Sentence 5: A bunch of talk. We need to look for the presence of unwanted traits we will be more likely to succeed.

Develop partnerships between handlers, nurseries, retailers and CAC

The commercial development of a new avocado cultivar requires there to be control over the release of the plant material and the development of sufficient acreage of trees as to properly develop a market with good fruit value the supply of the fruit will also need to be managed. A formal partnership that recognizes patent rights, royalty streams, promotion and marketing costs and outreach would allow for a coordinated plan to commercially develop a new cultivar. Of greatest importance will be the

Here again we are developing new varieties, I thought this was not a priority

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creation of a partnership with a retailer who be willing to promote the new avocado fruit and ensure that there will be a good match between the supply of the fruit and the demand for the fruit.

Critical mass required

Once a new fruit variety has been commercially released the amount of trees planted should reflect the potential market for the fruit. The total acres will need to be carefully considered along with the potential pounds per acre of production taken from the information collected in the testing of the new variety.

Possible estimates for critical mass may be calculated using the following assumptions: The market be equivalent in pounds to 5% of the California Hass volume. At 400 million pounds this would be 20 million pounds. If the production levels were 10,000 pounds an acre, 2,000 acres would be required for the new variety. At 100 trees per acre 200,000 trees would be required. Given that budwood of the new variety would be limited planting of 2,000 acres may take a number of years.

Just talk and speculation

Marketing required

The information for marketing purposes will need to include the consistency of yields with low alternate bearing desirable, fruit size appropriate to the target users, the harvest season and maturity standards needed, the ripening and shipping characteristics of the fruit. Marketing research will be needed on the appeal to consumers, the consumer attitude and acceptance of genetic engineering.

Just talk, what does genetic engineering has to do with this?

Timeline

Long term funding commitment of at least 10 years preferably 20 years. Avocado trees have a long juvenile phase, often from 5 to 7 seven years, from the seedling stage to flowering and fruit set. This extended time period greatly increases the time needed to evaluate the tree for beneficial traits. Once the new tree is determined to be worth further evaluation additional trees need to be propagated to allow testing on large numbers of trees. New trees can take two years to propagate and then a further 5 to 7 years before enough fruit are produced for testing. Potentially 14 or 15 years may pass before a new cultivar is ready for

Sentence 3: This is true in some cases especially when wild varieties are used. Often there is a fair number of precocious seedlings.

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commercial release. If genetic traits are to be manipulated there could be several more years added to the development and testing time for a new cultivar. The commercial development of a new cultivar could also take a 5 to 7 years to build up sufficient acreage so that sufficient volumes of fruit are available for marketing the fruit. Such a long term investment requires a stable research environment in funding, experimental sites and ongoing cultural care.

Appendix 2

What are the desirable traits for new varieties? This is really not far off what is written here; but it is all about new varieties not rootstocks.

For the investment in plant breeding to be successful it is necessary to have a sharply focused program designed to resolve industry problems that may be essential to the sustainability of the California avocado industry. To create new cultivars with only a small number of well‐defined desirable traits requires clear direction as to which traits have the highest priority and the most commercial significance when the new variety is ready for commercial release.

Okay

When the desirable traits of a new avocado variety are considered a very long laundry list of traits is often drawn up. Unfortunately, it would appear that a very long time, probably several centuries, would be required using traditional breeding methods to create the ideal avocado fruit type. Even with the new genetic techniques it could be many decades before a new fruit type with many desirable traits could be produced. The experience of the root stock breeding program where there has been only one well defined trait of root rot resistance has shown that even just breeding one new variety with a single well‐defined trait is a challenge.

The desired traits of a new fruit variety have been defined. Appendix 1 contains a list of potential traits for new fruit types. There were 35 traits for scion breeding and 13 traits for rootstock breeding listed by Berg in 1976. More recently industry stakeholders identified 19 unique traits. Such lists of traits is quite extensive and detailed and it would appear to be unrealistic to create a new cultivar with all desirable traits within a reasonable timeframe. Limiting traits to a maximum of 2‐3 of the most

Bergh did this with Gwen

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important and maintaining other desirable traits as not wholly negative in a new cultivar appears to be the most realistic goal when developing new cultivars. To select a small number of traits it is necessary to put priorities on the most desirable traits to guide plant breeders

Avocado Trait Objectives

The table below lists the traits Dr B.O. Berg was using in evaluating seedlings for suitability as new avocado cultivars.

(B.O. Berg, 1976 Proceedings of the First International Tropical Fruit Short Course)

Fruit quality

Medium size Thick ovate shape Uniformity Pulp Skin Proper softening Medium thickness Appetizing color Readily peelable Absence of fibers Insect, disease resistance Pleasing flavor Free from blemishes Long shelf life Attractive color Slow oxidation Long on the tree storage Chilling tolerance Seed High oil content Small High nutritional value Tight in its cavity

Shoot qualities

Spreading habit Tolerant of chlorosis Easy to propagate Tolerant of other stresses Strong grower Short fruit maturation period Tolerant of pests and diseases

Precocious

Tolerant of wind Regular bearing Tolerant of cold Wide adaptability Tolerant of heat Heavy bearer Tolerant of salinity

Rootstock qualities

Conducive to high quality fruit

Easily grafted

Conducive to healthy, productive trees

Tolerant to Phytophthora and other organisms

Free from sun‐blotch Tolerant of salinity Dwarfing or semi‐dwarfing Tolerant of chlorosis

All the quality attributes below have been basically achieved with the Gwen also most of the fruit characteristics and more Regarding Shoot qualities: I don’t know about chlorosis but the Gwen has many of these requirements. For Rootstocks, Ben Ya’acov did much of this

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Genetically uniform Tolerant of drought Hardy and vigorous Tolerant of other adverse soil

conditions Easily propagated

Goals and Traits identified through industry consultation

To identify the goals and most desirable traits, three meetings were held, one with researchers and the PRC, and two with growers and handlers in the northern and southern growing regions.

1. California industry stakeholders

Summary of goals and traits identified by growers and handlers

1. Improve the Hass variety while retaining the best characteristics of Hass

a. Retain i. Good flavor ii. Good storage life for shipping iii. Thick/Robust skin iv. Good texture v. Colors when ripens hiding blemishes vi. Good pulp to seed ratio

b. Improve i. Flowering time to a later warmer more

stable period ii. Reduce alternate bearing iii. More compact upright tree shape iv. Tolerance to salinity v. Tolerance to pests and diseases

2. Produce new varieties that better tolerate stress

a. Environmental i. Cold ii. Heat

b. Water i. Drought ii. Salinity

c. Soils i. Heavy soils ii. Alkaline soils

d. Pests and diseases

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i. Soil diseases ii. Cankers iii. Leaf feeding pests iv. Fruit feeding pests

Summary of goals identified by the University of California Who at the UC identified these goals?

1. Genetically improve crops to a. increase yields b. introduce novel traits c. adapt plants to water‐limited conditions

Summary of goals and traits identified by current UC researchers Who are the researchers you are referring to?

1. Diversify away from Hass a. Fruit quality equal or better than Hass b. Early and late maturity to add to the shoulders

of the season and replace Hass c. Reduce alternate bearing d. Trees with growth habits for high density

plantings e. Adaptability to different environments f. Salinity and drought tolerant g. Tolerant to pests

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Collect seed

Germinate seed

Cross selections

collect fruit Select seedlings

Grow selections

to produce fruit

Horticultural

evaluation

Propagate best

selections

Release for

commercial use

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