ASSESSMENT OF GENETIC DIVERSITY IN WORLD CHICKPEA GERMPLASM BASED ON MORPHOLOGICAL AND BIOCHEMICAL GENE MARKERS

Abstract

Wurld cole coll(:cliul' flf Clw:kpcn (Clcer orielfmll/l LJ 1Iiong wilh local accc::;siulls {"n1icclcti from ul! nvc, the country \Va." evaluated for six qualitative ~tl(l fOllr quantitative trails including discl1se (Ascorhy la rall;e;) reaclion al National Agricu lhual Research Centre (NA RC), Islamahad under l'IIinfed cond itions. Qui of lolnl 423 ilccessiolls, )60 acccs:-:io lls were exotic, sixty were local and three were improved vari eties. The accessions dilTered s ignificantly lo r planl Irails of quali Ta tive Ilnlllre with distinct classes like growth hilbit, iron deficiency_ nower colour, plant pubescence, planl pigmentation and pod s ize. AlIlhe exotic gennplas111 WilS badly infected with Ascochyta blight, hence sixty local nccess;om: were selected for further investigation, These were evaluated on single plan! progeny basis during winter 1997 for genelic di versity ba,~ed on morphologica l, quantitative traits al1(\ biochemical markcrs. 1'01' quantitative trait s, CV and genetic varirlllce revealed thnt the re~ar l ts cou ld be of broader spectrum . 'nle negative association of days 10 flowering with days to maturity in the tolal gerl11plasm. may be d\le to disease inrection at the time of pod ICll matioll, caused rorced mall!! ity ;1nd little seed W(1S obtrl;ncd . The lotal gerlllpl:1sl11 (1173 aCfc~si(lns) was grollpcd into 10 d1lsters h<lsed Oil average linkage distance. Cluster I consisted of 60 accessions. cluster 11 -5(,; cluster HI-7]; cluster IV-53, chisler V-62, cluster VI·26, cluster VII-35, cluster VIII·20, cluster IX·23 and clusler X-15 accessions, All the exotic tlccessions were grouped in the clusters I, II, III, IV. VIU and X. whereaS' ot ll er clusters C(lTlsi,c:led of 111ixed 8(',cessiOlls of loca l and exotic ori gin. 011t of6J locrll accessions (including 3 va ri eti es), eleven were in the cluster V, sixteell in cluster VI, seventeen in cluster VII and l1l11eteen in the cluster IX. As the Ilumher of accessions from various SOI I1'ces were grouped in a systematic way, thcrelore, relatiollship may be est abl ished between origin and clu stering pattern, The selected accessions from v~l ri Olls clusters <lrc slIgge.c:tcd to be \1sed ill crop improvement in fu ture. Variance studied by [leA revealed that cluster analyses greJllped together access ions with greater genet ic similarity, but cl1Isters did not necessarily include all the accessiolls from some origin. Severa l potentially illl port:lllt (lgrol1omic types from particular groups have been iden!i lied which nlny be exploited ror genetic lIuteHlia! 10 trullsfer Ihe desirah le genes and this, along with biochemical nnalyl'>cs, will f"cilitate ill Hl'il'iemhling a COre collection 110m th¢ large genetic resotll'ces. The 3cccs . .,iollS collected rrom Ln yyah dislrict were better in evaluation as compared In other four Illnjor chickpe.'l growing districts o r Pakistan. Therefor I the selected al:ccssiolls rrom thi!> area cO\lld he tested under 3 wide I1l llge of environment!' or tlsed in hybridi 7o tion pmgrn mllle. As locnl material is better adapted, indicating the worth lor improvitlg seed weight in chickpea, hence it could be util ized by the breeders or chickpea by involving local and exotic c hi ckpea parents in the breeding programme. In the present study, Illultivariate npproach has proved to be 1110re useful tool, it produced five clu sters on the basis of prov in c ial d ist ribllti on I1lllch more differentiated when compared to the initial subdi vision according to geograp hic s ites o r chickpea. The study confimled the ex istence o r a wealth of phenotypic divergence in the 10c:'!1 chickpea gemlp lasll1. Further, collecting missions 10 main chickpea growing areas with greater divers ity could concentrate ellorts on sampling as many geographically and ecologi ca ll y d isLinct a reas as poss ible, ra th el' th,m collecting extensively fhun fi elds c lose to ll1otorable roads within individll!ll province. Conclalion und path coe((icient ami lyses cvndw.:teJ in a replicated trial revealed th:'!t pods pe l' plant {lnd IOO-seed weight had the max.i l1H1nJ contribution in dete rmining gr" in yie ld, the IIItil11<1te product in chickpea under ra in red conditions. further, il was observed thai high indirect contribution was exhihited via secondary branches and harvest index by most o f the yie ld components, hence these two traits along with pods per plant and IOO-seed weight <Ire s uggested to be given empha sis while selecting hi gh yie lding chickpea cuiti v<lrs for minfed condi lions. Correla tion a nd path coeffi c ient analyses indicated that pods per plant a nd IOO-seed weight were potent contri butors to grain yield through direct effects. Although, biological yield had significant association but exhibited negative direct effects. On the basis o r performance, seven access ions produced higher grain yield than hoth the checks hence were selected for fl leather evaluation under a wide range of environmental conditions.