Identification of microsatellite markers associated with staygreen trait in wheat RILs

Abstract

The Recombinant Inbred Lines in F7 generation derived from two crosses (Ning8201 x Sonalika and Yangmai6 x Sonalika) along with parents were evaluated for varying degree of expression for staygreen, for two consecutive years in two replications. LAUG values ranged from 73.87 to 75.62 in staygreen parents, Ning8201 and Yangmai6, as compared to non-staygreen parent Sonalika (10.38). F1 showed intermediate behaviour for staygreen expression indicating additive nature of inheritance for the trait. The distribution of RILs was normal indicating polygenic nature of the trait. Analysis of variance for LAUG displayed significant GxE interaction. Of the 119 SSR markers used in two crosses, 22 were polymorphic on parents. In Ning8201 x Sonalika, SSR markers WMC-10,WMC-74, and WMC-76 were significantly (p less than 0.001) linked with staygreen trait. In the other cross (Yangmai6 x Sonalika) the markers BARC-109, BARC-1120, BARC-04 and BARC-74 were significantly linked. The polymorphic markers for both crosses grouped under one linkage group (MAPMAKER/ EXP 3.0b). Two QTLs were detected in Ning8201 x Sonalika cross (R2=8.28) and (R2=18.11). A major QTL was detected in Yangmai6 x Sonalika, which alone explained 44.34% of the phenotypic variation. The rest of the loci contributed on an average 12.9% to the total phenotypic variability. The linked markers obtained in the present study for staygreen trait can be used further for fine mapping and cloning of gene that can be used further for molecular assisted breeding in wheat.