Exploring Distribution and Evolution of Haplotypes in Rice Landraces across Different Rice Cultivation Regions in Yunnan.

: Rice blast, caused by , seriously damages the yield and quality of rice worldwide. is a durable resistance gene that combats carrying . However, the distribution of the gene in rice germplasms in Yunnan Province has been inadequately studied. : We analyzed the potential molecular evolution pattern of alleles by examining the diversity in the coding sequence (CDS) among rice varieties. : The results revealed that 95% of 405 rice landraces collected from different ecological regions in Yunnan Province carry alleles. We identified 17 nucleotide variation sites in the CDS regions of the gene across 385 rice landraces. These variations led to the identification of 28 haplotypes, encoding 12 novel variants. Among these, 5 haplotypes (62 rice landraces) carried alleles. The evolutionary cluster and network of the haplotypes suggested that the alleles were the ancestral alleles, which could potentially evolve into variants through base substitution. : This study suggests that alleles are diverse in the rice landraces in Yunnan, and the sites resistant to blast evolved from the susceptible plants of the rice landraces. These results provide the basis for breeding resistant varieties.