Identification of genomic regions conferring drought tolerance in bread wheat using ISSR markers

摘要

Drought stress is one of ever escalating and disastrous situation for plantadaptations under changing climate. Quantitative Trait Loci (QTL) analysis was done to identify chromosomal locations containing QTLs for photosynthetic rate, relative water content and cell membrane stability under drought stress conditions. An F 2 population was developed from an intraspecific cross between a drought tolerant genotype (Chakawal-50) and a drought susceptible genotype (9436) of Triticum aestivum . A total of 30 ISSR markers were used to screen both parents. Only 4 ISSR markers were found polymorphic which were used to score 180 F 2 plants. A total of 73 bands produced were found polymorphic from these 4 markers using capillary electrophoresis. One QTL was found linked to Photosynthetic rate on chromosome 3A, one to relative water contents on chromosome 4D and one to cell membrane thermo-stability on chromosome 2B, respectively. As these traits were also positively correlated with thousand grain weight, so indirectly these QTLs might improve plant yield under limited water conditions. Therefore, these QTLs may be used through marker assisted selection while breeding wheat under limited water conditions.