Response of quantitative and physiological traits to drought stress in the SeriM82/Babax wheat population

Abstract

Assessment of quantitative traits in bi-parental progenies provides a strategy to identify drought tolerant genotypes and stress-adaptive traits in wheat. A recombinant inbred line (RIL) population with 167 lines produced from the SeriM82/Babax cross was subjected to normal irrigation and drought stress (at the heading stage) under field conditions. The study was done in Bajgah, Shiraz, Fars province, Iran, during three consecutive seasons. Shiraz is located in a temperate, major wheat production region of Iran that is prone to periodic drought. The aims of this study were to identify drought tolerant RILs and drought adaptive traits. The mean grain yield was 237.91 and 148.60\xa0g\xa0m−2 under normal irrigation and drought stressed conditions, respectively. Above 48.0% reduction in grain yield was observed under drought stress in the three consecutive growing seasons. Several RIL lines had high grain yield under both moisture regimes. The mean leaf relative water content (RWC) was 0.4 under drought condition. One RIL had relatively high RWC and grain yield under both treatments. Heritability of several traits did not change between the two moisture conditions whereas it was reduced for few of traits. Assessment of the interrelationship of traits showed that RWC, days to heading, awn length and spikelets per spike were the main contributors to grain yield that became more important under drought conditions. Given the relatively high heritability values estimated under both conditions and strong association with grain yield, these drought adaptive traits could be used for indirect selection to improve drought tolerance in this region of Iran. Overall, information of the identified drought adaptive traits and RILs lay foundation for the improvement of drought tolerance in wheat.