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