Identification and validation of blast resistance Pi1 gene in the derived mapping population of rice variety, NLR34449 through molecular markers

NLR34449 is a popular, blast resistant, high-yielding variety, with highly desired fine-grain type and hence commands a premium price in the market. The nature and genetics of resistance to blast disease in this variety was not reported previously. Molecular marker-based screening using gene linked markers for ten blast resistance genes showed amplification of the resistance allele only with respect to the marker RM224, which is specific for Pi1 gene. In order to confirm the role of Pi1 gene with respect to blast disease resistance in Nellore Mahsuri, a F2 mapping population derived from the cross Nellore Mahsuri/Improved Samba Mahsuri (blast susceptible variety) was studied. The F2 plants segregated in ratio of 3 resistant: 1 susceptible indicating monogenic, dominant nature of inheritance with respect to blast resistance. Thus, the current study demonstrated that blast resistance in NLR34449 is contributed by Pi1. © 2023, Indian Phytopathological Society.