Molecular Mapping of QTLs for Wheat Abscisic Acid Content Under Water Stress

A segregating F4 population from the cross between drought sensitive (Yecora Rojo) and drought tolerant (Pavon 76) genotypes was made to identify molecular markers linked to wheat (Triticum aestivum L.) abscisic acid (ABA) content under water-stress. The parents and 150 F4 families were evaluated phenotypically for drought tolerance using two irrigation treatments [0.25 and 0.75 m³ (H₂O) m^-2(soil)]. Using forty different TRAP primer combinations, 98 different SRAP primer combinations and 400 SSR primers were tested for polymorphism among parental genotypes and F4 families, the results revealed that quantitative trait locus (QTL) for ABA content was associated with 3 TRAP markers, 4 SRAP markers, and 9 SSR marke and explained phenotypic variation ranged from 15 to 45 %. The genetic distance between ABA content QTL and TRAP 1, TRAP 9, and TRAP 14 were 19.2, 13.5, and 17.5 cM, respectively. The markers SRAP5, SRAP89, SRAP93 and SRAP95 had genetic distances of 23.7, 15.6, 20.2, and 19.0 cM, respectively. The SSR markers for ABA content had genetic distances ranged from 11.0 to 24.3 cM. Therefore, the TRAP, SRAP and SSR markers linked to the QTL for the drought-induced ABA content can be further used in breeding for drought tolerance in wheat.