Candidate Gene Mapping, Pyramiding of Stay-Green and Water use Efficiency Qtls and Mapping of Putative Qtls for Root Traits using Ril Populations in Sorghum
Loading...
Date
2012
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
UAS Dharwad
Abstract
Recombinant Inbred Populations (RIPs) derived from the crosses IS9830 x
E36-1 (RIP1) and N13 x E36-1 (RIP2) were used to map localize the drought
tolerance-related candidate genes through SNPs. A total of five QTLs flanked by at
least one candidate gene (SNP) were found common across both RIPs: qGLA3
(Xtxp38-Xsnp19); qGLA4 (Xiabt227-Xsnp56) qDAF2 (Xiumc136-Xsnp28) qPL4
(Xisp229-Xsnp36) and qSY4 (Xsnp36-Xtxp27).
The three stable QTLs for stay-green, qSTG1A:Xtxp34-Xtxp285; qSTG2:
Xtxp205-Xtxp231; qSTG3:Xtxp298-Xtxp324 and one QTL for water use efficiency,
qCID2:Xtxp6-Xiabt70 were introgressed from E36-1 the stay-green parent into
SPV86, SPV570 and M35-1. The foreground and limited background screening
across BC1F1, BC2F1, and BC3F1 generations was done and the BC3F2 progenies with
various QTL combinations in homozygous condition were identified and selfed. The
BC3F3 near isogenic lines (NIL) were evaluated in greenhouse: NIL with all four
QTLs in M35-1 (75.83 %), SPV86 (78.48 %) and SPV570 (75.57 %) backgrounds
showed per cent green leaf area (GLA) retention on par to the stay-green donor parent
(E36-1, 75.20 %) at physiological maturity.
The two RIPs: E36-1 x Basavanapada (RRIP1) and E36-1 x SPV70 (RRIP2)
segregating for high root volume and root length respectively were field evaluated
during rabi 2010-11. Analysis of variance revealed significance difference among the
RILs. A total of 113 (55/530 EST-SSRs, 40/275 SSRs, 18/138 SNPs) and 104
(50/530 EST-SSRs, 34/270 SSRs, 20/138 SNPs) polymorphic markers were
genotyped to construct a genetic linkage map spanning 1633 cM and 1800.1 cM, and
a total of 30 and 28 putative QTLs were mapped for root and yield related traits in
RRIP1 and RRIP2, respectively. The lack of overlap between the QTLs of component
traits of root and yield, suggested that these two parameters are independent and the
possibility of combining these two traits, favorably to enhance productivity of
sorghum under receding moisture condition.