Native ForbSeed Production in FloridaGenetics / Seed Dormancy

Dave Czarnecki II, Zhanao Deng, Jeffrey G. Norcini*, Sarah Smith, Fred Gmitter, and M. Nageswara Rao

Plant Material

What matters?

Sustainability• Seed / plant origin (ecotype)• ↑ Genetic diversity : ↑ sustainability

A A A A A A B A B A A A A A A A

A A A A A A A A A A A A A A A A

A B A C A A A A A A C B A A A A

A A A A A A A A A A A A A A B A

A A A A B A A A A A A A A A A A

A A A A A A A A A A A A A A A A

A A A A A C A A B A A A A A C A

A B A A A A A A A A A A A A A A

A A A A B A A A A A A B A A A A

A A A A A A A A A A A A A A A A

A A A A A A A A B A A A A A A A

A A A A A A A A A A A A A A A A

A A C A A A B A A A A A A A B A

A A A A A A A A A A A B A A A A

A A A A A A A A A B A A A A A A

A A A A A A A A A A A A A A A C

Gen. Diversity – Cultivar/Selection

Genotypes of population – mostly ‘A’, some ‘B’ and ‘C’

B B

B C C B

B

B

C B C

B

B B

B

C B B

B

B

C

Gen. Diversity – Cultivar/Selection

‘A’ is susceptible to a biotic or abiotic stress

A A H A I C B A B A I L C M H I

D C D M D B L C J B D B D A D C

A B A C A I M D K I A I M B A D

E I E L D F C M L F D F E I E A

M D A D B A D E I L B M A D F E

D A M A F D F G M C F I D L M J

A K D E J C G G B C J C F C D G

K B A I D A A E A A D A M B A J

F J D C B G L M J G B G F J D M

A F J D G C J K E I G A J F J K

M K A G A H M L B H L H L K L L

D D G C D I F G F C D E D D G G

J A C H J J B A K J D J E I C H

G L K A M K K D C K M K G L M D

F M I K D L C B D L D L I M K B

H A D A J I D C A B J D H A D C

Genotypes of population – ‘A’ to ‘M’

Gen. Diversity – Natural/No selection

H I C B B I L C M H I

D C D M D B L C J B D B D D C

B C I M D K I I M B D

E I E L D F C M L F D F E I E

M D D B D E I L B M D F E

D M F D F G M C F I D L M J

K D E J C G G B C J C F C D G

K B I D E D M B J

F J D C B G L M J G B G F J D M

F J D G C J K E I G J F J K

M K G H M L B H L H L K L L

D D G C D I F G F C D E D D G G

J C H J J B K J D J E I C H

G L K M K K D C K M K G L M D

F M I K D L C B D L D L I M K B

H D J I D C B J D H D C

Gen. Diversity – Natural/No selection

A’ is susceptible to a biotic or abiotic stress

http://edis.ifas.ufl.edu/ep297

Wildflower Seed Production

Floridawildflowers.com

• Minimal weeds

• Maximizes yield

• Maintains genetic diversity

Landscape Fabric System

Seed HarvestingVacuuming

Genetics

Coreopsis leavenworthii

Coreopsis leavenworthii

Prod. Pops.

• Leaf type• Growth habit• Plant survival through winter

• Days to bloom• Flower color• Flower size

Phenotypic Diversity

Molecular Diversity – advantages• Insensitive to environmental

changes• Many data points generated

246 plants X 320 loci = 78,720 vs.1,476 (Morphology)

• Screen large number of lociRelatively fast

• More accurate interpretation of population diversity

DNA Markers and Diversity

PCA ResultsPhenotypes

Production and Natural C. Fla.

Populations

Genotypes

• Maintained identity even at locations distant from origin

Also, noted that:• High level of diversity within populations• Low level of diversity among populations

Possible to produce highly diverse seed in locations other than the area of origin

Production Populations

C. leavenworthii C. tinctoria

• Can hybridize • C. leavenworthii is narrowly endemic• C. tinctoria is present in much of the US

but only 6 Florida countiesEscambia, Lake, Highlands, Miami-Dade,Madison and Leon counties

• C. tinctoria present in 3 of the same counties as C. leavenworthiiLake, Highlands, Miami-Dade

C. leavenworthii and C. tinctoria

C. tinctoria has trichomes on leaf petiole. Hybrids too?

Morphological Markers

C. tinctoria and hybrids have red spot.

Hybrid

One of the three field blocks for study of natural gene flow from C. tinctoria to C. leavenworthii. Seeds were being collected from one of the 27 pollen trap plots.

Seed Dormancy

• Germination and emergence- weed interference- erosion

• Sustainability- seed bank reserves

Seed Dormancy - Importance

• Seed origin (genetics)• Harvest season (environment)

- temp., light, water, nutrition• Storage conditions

Seed Dormancy

After-ripening to break dormancy

“Afterripening is loss of the dormant state over some period of time through exposure of the seeds to a set of environ-mental conditions after maturation and separation from the parent plant.” Foley, M.E. 2001. Weed Science 49:305-317

Coreopsis after-ripening study• 1-24 weeks @ 59 or 90oF - 33% RH, except 23% RH for C. lanceolata• Then 24 weeks in commercial, cool storage unit - 23% RH and 63-66oF

Seed Dormancy

cotyledon

pericarp

testa

endosperm

Coreopsis floridana

0

20

40

60

80

100FreshARStored

Coreopsis basalis

0

20

40

60

80

100FreshARStored

AR – 59oF, 33% RH

Results for seeds AR 12 wk,stored 24 wk @ 63-66oF, 23% RH

AR – 90oF, 33% RH

0

20

40

60

80

100FreshARStored

Coreopsis floridana

0

20

40

60

80

100FreshARStored

AR – 59oF, 33% RH

Results for seeds AR 2 wk, stored 24 wk @ 63-66oF, 23% RH

AR – 90oF, 33% RH

*72% for seeds AR 24 wk, and then stored 24 wk

*

**75% for seeds AR 24 wk, and then stored for 24 wk

**

0

20

40

60

80

100InitialFreshStored

Coreopsis lanceolata

0

20

40

60

80

100FreshARStored

AR – 59oF, 23% RH

Results for seeds AR 24 wk,stored 24 wk @ 63-66oF, 23% RH

AR – 90oF, 23% RH

0

20

40

60

80

100FreshARStored

Coreopsis leavenworthii

0

20

40

60

80

100FreshARStored

AR – 59oF, 33% RH AR – 90oF, 33% RH

Results for seeds AR 12 wk,stored 24 wk @ 63-66oF, 23% RH

Coreopsis after-ripening study• C. basalis - AR at 59 and 90oF; viability maintained• C. lanceolata - best AR after 25-48 wk of cool temps. - maybe AR at 90oF for 24+ wk - viability maintained• C. floridana - slight AR but store cold/dry or lose viability• C. leavenworthii - 90oF increases germ but slight loss in viability

Seed Dormancy

• Cool, dry environment

temp. + RH 100

ex.: 35oF, 40% RH 35+40 = 75 (best is RH < 50%, and total < 75)

*** As temp. ↓ RH ↑ *** (must cool AND dehumidify air)

• Protect against insects and rodents

Seed Storage

Labs Specializing in Testing Seed of Native Species

Ransom Seed Laboratory, Inc.PO Box 300Carpinteria, CA 93014-0300(805) 684-3427Ransomsl@silcom.comhttp://www.ransomseedlab.com

Mid-West Seed Services, Inc.236 32nd AvenueBrookings, South Dakota 57006(877) 692-7611info@mwseed.comhttp://www.mwseed.com

• Leaf Type• North: most complex• Central: moderately complex• South: most simple

• Growth Habit• North, CP1, and C2: mostly all upright• C3: mostly semi-upright or decumbent• S1: almost entirely semi-upright or decumbent

• Plant Survival• Little differentiation among populations

• Days to Bloom• North: most days to bloom• South: fewest days to bloom

• Flower Color and Size• Possible gradient of size and color from north to south

Phenotypic Diversity – Natural Populations

• Extremely uniform • Very similar to a natural

pop. from central Fla.• Almost upright• Correlation analysis

• Leaf, flower, and origin were highly correlated

Phenotypic Diversity – Production Populations