부산대학교 도서관

Indica rice (Oryza sativa L.) is sensitive to low temperature. Low temperature stress is common for the rice seedlings of first crop, and caused enormous yield loss in Taiwan. To improve the cold tolerance of indica rice seedlings, a screening model for the cold tolerance phenotype at the seedling stage was established in this study. We selected the japonica cultivar Taiken 9 (TK9) as the donor parent for its seedling cold tolerance, and used backcrossing breeding to breed a near-isogenic line of indica cultivar Taichung Sen 17 (TCS17), NSY1051070, which is cold-tolerant at the seedling stage. The agronomic traits of NSY1051070 are similar to TCS17, but it is more cold-tolerant than TCS17 at the seedling stage. Then we used TCS17, TK9 and NSY1051070 to do next-generation sequencing (NGS), and developed high-density single nucleotide polymorphism (SNP) markers for exploration of quantitative trait locus (QTL) associated with cold tolerance at the seedling stage. The results showed that NSY1051070 was with eight potential QTLs associated with seedling cold tolerance from TK9. These results may become the basis for the mapping of rice seedling cold tolerance genes and for the development of molecular markers of rice seedling cold tolerance, and it can help to improve the seedling cold tolerance of indica varieties in Taiwan. What is already known on this subject? Backcross breeding is an effective method to breed the near-isogenic lines of elite variety and improves its defect. What are the new findings? We developed potential molecular markers of seedling cold tolerance, improved the efficiency of breeding selection. What is the expected impact on this field? The results in this study contribute to improve seedling cod tolerance of indica variety in Taiwan, and allow farmers to reduce risks of production.