Molecular mapping of bacterial blight resistance gene, drought tolerant QTL(s) and genetic diversity analysis in clusterbean {Cyamopsis tetragonoloba(L) Taub}
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Date
2011
Authors
Bajaj, Anshu
Journal Title
Journal ISSN
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Publisher
CCSHAU
Abstract
The present investigation was carried out to screen genetic diversity using RAPD markers and to
identify and map the QTL for resistance to bacterial blight and drought tolerance in clusterbean .The
plant material was procured from Forage section . For bacterial blight, the resistant (HG 75) &
susceptible(PNB) genotypes were selected & crossed to generate F3 population. The F3 population was
used to map QTLs. For drought tolerance studies genotypes HG 563 (tolerant) & PNB (susceptible)
were used to generate the mapping population (F 2:3).The genetic diversity studies were carried out in
48 genotypes of clusterbean using 130 RAPD primers and 97 primers produced amplification of 705
alleles ;out of which 644 were polymorphic. The similarity ranged from 0.11 to 0.97.The dendrogram
grouped the genotypes into two major clusters at a similarity coefficient of 0.68. A variety FS277 was
out grouped which is a forage variety. The genotype GP96 and F5277 were found to be most diverse
(89%).The QTLs were identified for bacterial blight resistance using parental genotypes (HG75 &
PNB) & their F3 population. The F 3 population was screened artificially for disease resistance along
with the parent genotypes. Polymorphic primers were used to screen the F3 population & the major
QTLs were identified for disease resistance using parental genotypes, HG75, PNB and their F 3
population. A total of 83 RAPD primers were used to screen the parental genotypes out of which nine
primers were polymorphic. These primers were used to screen the F 3 population and the QTLs found
were L19 , D1, AB7 and QLTY 3. Parental genotypes HG563 and PNB and their F2-3 genotypes were
screened at field and net house for resistance to drought. Out of fifty genotypes, 12 were highly
tolerant, 23 were moderately tolerant and 15 were susceptible to drought. The parents were screened
with eighty seven primers out of which, sixteen were found polymorphic and nine QTLs were found
linked to drought tolerance. Loci OPQ 20,OPD10, OPD14,OPQ 12,OPAC 8 and OPF 9 were major
contributing QTLs and OPAC2,OPL3 and OPF17 are minor QTLs The diverse lines may be used for
breeding programs to improve the production of agronomically superior genotypes of guar. The major
QTLs for bacterial blight and drought tolerance may be used for introgression into agronomically
superior genotypes of guar.
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