Drought Tolerance in a Recombinant Rice Population and the Association between Yield and Its Components with Microsatellite Markers

In order to identify susceptible and tolerant rice lines to drought stress in a recombinant rice population, a total of 40 F7 lines were obtained from a cross between a local cultivar, Gharib, and an improved cultivar, Sepidrood, were evaluated in two environments, control, and drought stress, in the year of 2017 at the Rice Research Institute of Iran. The results of the phenotypic evaluation of the studied lines showed that all genotypes, while having general hypersensitivity and decreasing growth under drought stress conditions, showed different responses to drought stress. The results of cluster analysis of morphological traits showed that L27, L38, L29, L40, and L39 lines were identified as the most tolerant genotypes with the lowest percentage of trait reduction, the highest grain yield, and earlier maturity. After them, the L9, L17, L21, L26, L30, L12, L19, L23, L25 lines, Sepidrood, Khazar and Hashemi showed the highest yield under drought stress conditions. The regression analysis showed that 13 of the 20 studied microsatellite markers including; RM11943, RM431, RM12091, RM416, RM236, RM16030, RM555, RM211, RM423, RM12146, RM520, RM12023, and RM233A, were associated with more than one morphological trait related to grain yield under drought stress Therefore, these markers can be used in different rice breeding programs to screen and select the drought-tolerant cultivars and lines in areas under this environmental stress.