Genetic analysis and mapping of bacterial leaf streak resistance genes in Oryzae rufipogon Griff

Objective  To exploit major resistance genes of rice (Oryza sativa L.) to bacterial leaf streak (BLS), and provide a basis for enriching rice disease resistant gene resources and breeding resistant cultivars.

Method  Constructing a mapping population, we conducted genetic analyses of BLS resistance genes in Oryzae rufipogon Griff ‘DY19’ using the bulk segregant analysis method, and preliminarily mapped the BLS resistance gene bls2 through SSR molecular markers.

Result  The ratio of resistant and susceptible individual plants in F₂ population was in accordance with the theoretical segregation ratio of 1∶3, which showed that the resistance gene to BLS in O. rufipogon ‘DY19’ was consistent with single gene genetic pattern and controlled by one pair of main recessive gene bls2. This gene was mapped in a 4 cM region between molecular markers SL03 (23 474 851 bp) and SL04 (24 484 154 bp) on the second chromosome. This locus was a new disease resistance locus.

Conclusion  The BLS resistance in O. rufipogon ‘DY19’ is controlled by one pair of new major recessive gene bls2. It can provide a reference for further fine mapping.