Development of breeding lines with multiple stress tolerance to cold, drought, and high-temperature stress in rice (Oryza sativa L.)
摘要
Farmers and breeders recognize that multiple abiotic stresses occurring simultaneously are more harmful to crops than individual stress conditions. In this study, pedigree-based breeding was employed to develop multiple abiotic stress-tolerant rice breeding lines (MTU 1010/IRINMST-291), using stringent phenotypic selection for germination and seedling stage cold stress tolerance, reproductive stage drought stress, and reproductive stage high-temperature stress. Among the developed lines, IRINMST-007, IRINMST-338, IRINMST-418, and IRINMST-129 emerged as high-performing families under non-stress, drought, and high-temperature conditions during the reproductive stage. Additionally, IRINMST-007, IRINMST-418, and IRINMST-129 showed strong cold tolerance at the seedling stage and germination stage. These breeding lines have the potential to address food security challenges posed by abiotic stresses. A total of 110 parental polymorphic markers were used for single-marker analysis in the 180 selected F5 recombinant inbred lines. RM5344 were found associated with percent spikelet fertility at reproductive stage high-temperature stress with a phenotypic variance of 24%. RM5911 was found to be associated with grain yield at reproductive stage drought stress with a phenotypic variance of 11%. RM1019 was found associated with seedling growth under cold stress with a phenotypic variance of 18%. RM5344 was found associated with survival rate at seedling stage cold stress with a phenotypic variance of 19%. RM555 was found associated with vigor of germination at germination stage cold stress with a phenotypic variance of 18%. These markers can be used for molecular breeding programs to develop multi-stress tolerant rice varieties.