Genetic dissection for leaf correlative traits of rice (Oryza sativa L.) under drought stress

Water is becoming a restricted factor of agricultural development owing to the global shortage of water resources. Screening and improving drought tolerant rice cultivars would be helpful for increasing and stabilizing yield, economizing water and reducing environmental pollution. In this study, 127 rice lines of DII population derived from an indica variety Zhaiyeqing 8 (ZYQ8) and a japonica variety Jingxi 17 (JX17) were used to locate QTLs for leaf rolling, relative water content and rate of electric conductivity under drought stress. The results showed that significant differences between the parents were detected for all measured traits. The tremendous transgressive segregations for these traits were observed in the population. The frequency of all traits in the population was approximately normally distributed with slight skew. A total of six QTLs for the three traits were detected with molecular linkage map of 234 markers, including three QTLs (qLR-1, qLR-5 and qLR-11) for leaf rolling, two QTLs (qRWC-1 and qRWC-6) for relative water content and one QTL (qREC-6) for rate of electric conductivity. Visual measurement for leaf rolling can be used to screen a large number of rice germplasm resources or varieties, which is of importance to screening and utilization of drought tolerant rice varieties.