Molecular mapping of rice root-knot nematode (Meloidogyne graminicola) resistance gene in Asian rice (Oryza sativa L.) using STMS markers

Rice root-knot nematode, Meloidogyne graminicola is one of the major pests of rice cropping system and is responsible for considerable yield reductions. Out of various management options tried so far, the resistance against M. graminicola in rice could be the most valuable in alleviating this problem. In present study a rice cultivar Abhishek exhibited a strong resistance with least number of galls (2galls/plant) and a kind of necrotic browning of roots which is typical of R-gene mediated resistance response. In order to map the gene governing resistance to root-knot nematode, the cultivar Abhishek was crossed with the Bangla Patni, a highly susceptible genotype to generate F₂ mapping population. Using bulked segregant analysis, a marker HvSSR10–21 was identified to be putatively linked with the resistant locus in cv. Abhishek with significant LOD score. The significant LOD score value indicates the linkage between identified marker and the resistant locus against M. graminicola. We designate this gene as Mg1(t).