Identification Of SNP Markers For Drought Tolerance In Wheat.

Drought stress has a direct impact on crop yields often leading to crop failures, rapid decline in food supply and availability as well as turbulent food prices that could consequently lead to civil unrest. Breeding for drought stress tolerance and wheat streak mosaic virus resistance is fundamental component of food security especially for staple food crops such as wheat. A set of 217 F7 wheat recombinant inbred lines (RILs) derived from CO960293-2/TAM111 were phenotyped across two dryland environments and three well-watered environments. Grain yield, yield components and agronomic traits were recorded. Genotyping was done using 90,000 SNP markers based Infinium assay and SNP calling was done using genome studio. Linkage grouping and QTL analysis was done using JoinMap and MapQTL, respectively. Data from three environments and 1420 polymorphic SNP markers were used for QTL analysis. Common putative QTLs for grain yield were mapped on chromosome 2A and 5B for all three environments . One common QTL for grain yield was mapped on chromosome 6B for two of the three environments used in the analysis. Several QTLs for 1000 kernel weight (1000KW) and kernel number head-1 (Knph) were mapped on chromosome 5B and 2A. One QTL for 1000KW was co-localized with QTL fro grain yield on chromosome 5B. The R2 for the QTLS ranged from 5.9-9.2 %. The SNP markers linked to novel QTL for drought tolerance could be utilized for marker assisted breeding for drought tolerance in wheat.

*Corresponding author (SLiu@ag.tamu.edu)