Cassava germplams characterization

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  • 1.TaxonomyKingdom : PlantaeDivision: MagnoliophytaClass : magnoliolpsidaOrder : MalpighialesFamily: EuphorbiaceaeSubfamily : CrotonoideaeTribe : ManihoteaeGenus : ManihotSpecies : M. esculenta

2. Introduction Origin Brazil Highly cross pollinated crop Duration 7 months to 2 years Introduced to Africa and Asia from southAmerica Grown in 90 countries 3. Contd Cassava ranks 4th after rice, sugarcane, and maize Extensively cultivated countries are Argentina,Brazil, Colombia, and Paraguay Area under cultivation 16 mha Provide food & livelihood for >500 million people inthe world- Best and Henry, 1992 4. ContdBiochemical aspectsRoot: Roots are mostly contain carbohydrates Also rich in vit.C, carotene, Ca, and K Poor in proteinLeaf: Rich in protein and vitamins Consumed as a vegetable 5. Genome structure 2n = 36 Genome size - 1.67 pg772 M bp in the haploid genome 6. GermplasmWorld germplasm collection held at CIAT, ColombiaHas around 5,724 accessionBrazil 1,340 accessionsColombia - 2,003 accessions Kenya Uganda Rwanda Burundi Congo Madagoscar 7. Wild speciesManihot anomalaM. caerulescenceM. epruinosaM. flabellifoliaM. glazioviiM. dichotomaM. tristisM. peruvianaM. maracasensis 8. UsesStarch as raw material for Paper industries Textiles Pharmaceuticals Animal feed Sago industriesand also used as a poultry feed 9. MarkersPhenotypic marker Graner (1942) described two morphological markersLeaf shapeRoot colour Hershey & ocampo (1989) described eightmorphological markers located on the stem, leaves,and root. 10. cassava phenotypic markers OrgansTypesErectPlant shape Tall and spreadSpread1. GreenColour of the 2. Yellow-greenyoung part of 3. Green and beginning of petiole redthe stem4. Green and beginning of petiole red with red ribs5.Green and red in equal area6.Some traces of green7.Entirely light redGreenColour of the coloured base and green scaleseye (bud) Green base and coloured scalesEntirely coloured 11. Emergence of eye (bud) Deep ProjectingAlignment of internodes Zigzag(young part) Straightleaf shape Palmipartite (normal shape) Palmisequate (the lobes totallyseparate) Entirely green Yellowish greenColoration of petiole Vivid red Purple red Entirely purple Less than 3Number of leaf lobes 3 to 5 5 to 7 7 to 9 12. Very narrowParallel edgeShape of lobesNormalWideRounded with two widening pointsProximalForm of lobes defined by position ofMedianmaximal widening pointTerminalWhite without chlorophyllLight greenColoration of upper surface of lamina Yellow-greenDark greenPurplishGreenWhitish-greenColoration of underside of lamina Yellow-greenPurple of redAlways greenred of upperside of young leavesColoration of lamina nerves red on underside of young leavesred on both side of young leaves 13. Leaf variation 14. Stem variation 15. Tuber variation 16. Inflorescence 1. WideForms of sepals2. Medium 3. narrow 1. Entirely green Sepals colour in female 2. Green and coloured nerveflower 3. Red and green 4. Red to purple 1. Always straight Shape of 6 wings on the 2. Straight then sinous at maturityovary with 3 carpels 3. Sinous then straight at maturity 4. Always sinousOvary body colour1. Green 2. Red 17. Root 1. Short ( < 40 cm )Length of root 2. Normal ( 40 to 80 cm ) 3. Long ( > 80 cm) 1. ConicalShape of root2. Fusiform 3. Cylindro-conical 4. cylindrical 1. SmoothTexture of root surfaces 2. Medium 3. RoughAppearance of external 1. Grey and thinbark 2. Brown and thickColour of pulp 1. White 2. Yellow 18. Biochemical Marker Isozymes fingerprinting and genetic diversity studies(Hussain et al., 1987; Ramirez et al., 1987; Ocampo et al.,1992; Lefevere & Charrier., 1993a) Applied to characterizing relationships among cassavaaccessions (Lefevere & Charrier, 1993b; Wanyera et al.,1994) Alpha & beta esterase more informative,provide 22alleles, which have complemented morphologicaldescroptors for identification of duplicates in cassavagermplasm (Ocampo et al., 1995) 19. Molecular / DNA Marker Independent to environment Stable Important to study the genes, genomes, andgenetic diversity. 20. Development of DNA markers1st generation DNA markers RFLP (Grodzicker et al., 1974) VNTR (Jeffreys et al., 1985) ASO(Saiki et al., 1986) AS-PCR (Saiki et al., 1986) OP(Beckmann, 1988) SSCP (Orita et al.,1989) STS(Olsen et al., 1989) 21. 2nd generation DNA Markers RAPD(Williams et al., 1990) AP-PCR (Welsh and Mc Cleland, 1996) STMS(Becknann& Soller, 1990) RLGS(Hatada et al., 1991) CAPS(Akopyanz et al.,1992) DOP-PCR(Teknins, 1992) SSR (Akkaya et al., 1992) MAAP (Caetano-anolles et al., 1993) SCAR(1993) 22. New generation markersIRAP ( 1998 )REMAP( 1999 )MSAP ( 1999 )MITE ( 2000 )TE AFLP ( 2000 )IMP ( 2001 )SRAP( 2001 )Others ISSR SAMPL AFLP/SRFA ASAP CFLP ISTR SSAP RBIP 23. Molecular / DNA Markers used in Cassava RFLPs(Botstein et al., 1980) SSRs (Litt & Lutly, 1989a,b) RAPDs(Williams et al., 1990) Minisatellites (jeffreys et al., 1993) AFLPs(Vos et al., 1995) 24. Relationship analysis of closely related species tocassava based on microsatellite PCRTo study phylogenetic relationship between cassavaand its closely related species from south America Manihot esculenta ssp esculenta M. esculenta ssp flabellifolia M. esculenta ssp peruviana M. pilosa M. triphylla 25. ContdMultilocus markers are usedRAPD, AP-PCR, DAP, AFLP, & SSRRecently oligonucleotide based SSR usedTwo kinds of SSR dataSequence data baseSpecific genomic libraries 26. ContdResult Varied amplification No of band is varied from 1 15 Fragment size varied from 200 3000 bp Scored as dominant marker Highest genetic diversity observed in M. esculenta ssp.Flabellifolia followed by, M. esculenta ssp esculenta,M. pilosa, M. esculenta ssp peruviana, M. triphylla 27. CMD resistance conferred by dominant gene BSA Identify a SSR markers linked to the CMDresistant gene 186 SSR markers are used 28. Contd Resistant gene CMD 2 Flanked by SSRY28 & GY1 @ 9 and 8cM respectively CMD resistant cassava TME 3 X TMS 30555 158 individual was established invitro from embryo axes thesub cloned Transfer the plants into a field with low CMD pressure CMD resistance evolved at 3 to 6 month old plant Scoring 1 to 5 29. Genetic mapping of a CMD resistant gene 186 SSR markers 80 SSR markers map positionsare known SSRY28 differentiate the CMD resistant genotypefrom CMD susceptible genotype SSRY28 located on 17th chromosome of male-parent-derived molecular genetic map Flanked by GY 1 & Ail 9b markers 30. Result All 10 plants of each resist genotype in all 3replication are showed without any visiblesymptoms Susceptible genotypes are always heavily infected SSRY 28 present in resistant genotypes and not insusceptible genotypes. 31. Most popular Dormaa, Wenchi, Nkoranza,& Asonafo 50 Genotypes are taken 4 primers (OPK-01, OPR-02, OPR-09, IOJ-14) 41 different bands detected Range of polymorphism % is 90% - 100% 32. 67 unlinked SSR loci assessed283 accessionsGrouped into 14 33. 76 varieties are grown in Rewa31 varieties taken for AFLP analysis with some wild speciesTo assess: Intravarietal diversity Genetic variability in the local varieties 34. 78 accessions evolved 1-breeding stock (clone 58308) 5-improved lines 10 - CMD susceptible 62 - CMD resistant36 SSR Markers are used 35. Institutes CIAT- Colombia IITA- Nigeria CDH - Africa CTCRI - India, Indonesia, Tanzania ESARC - Africa INEAC - Belgian Congo IRAT- West and Central Africa IRAM- Madagascar MARDI - Malaysia IICA- Venezuela, Mexico, Brazil, Colombia, Costa Rica