Revealing Novel Genetic Resources and Detecting Major Blast-Resistant Genes in Diverse Rice Landraces of Bangladesh

Rice blast, caused by the destructive fungal pathogen Magnaporthe oryzae , poses a significant threat to global rice production. Developing resistant rice varieties using new resistant sources is the most effective method to manage this disease. This study aimed to (i) evaluate the phenotypic responses of forty-four native rice germplasms from Bangladesh to M. oryzae, and (ii) identify major blast resistance genes present in these germplasms using molecular markers. Among the evaluated germplasms, nine (Acc. 3058, Acc. 3060, Acc. 3068, Acc. 3071, Acc. 3073, Acc. 3975, Acc. 3076, Acc. 3083, and Acc. 3085) exhibited moderate resistance, while one (Acc. 3080) displayed very high resistance to M. oryzae . Out of eight molecular markers tested, the marker Pita3, which is tightly linked with the Pita gene, showed a significant association (p=0.003, R2=0.19) with blast resistance. Based on the combined genotypic and phenotypic data, the rice genotypes were grouped into two distinct population subgroups, with Acc. 3076 forming a separate cluster in the analysis. Our findings suggest that Acc. 3058, Acc. 3075, Acc. 3076, and Acc. 3080 are promising genetic resources for developing durable blast-resistant rice varieties and for the discovery of new resistance genes against M. oryzae .