Genetic Relationships of Brown Planthopper Resistance to Dwarf Disease and Stripe Disease Resistance in Rice

Abstract

In order to clarify the linkage relationships among resistance genes to the brown planthopper, Nilaparvata lugens Stal., the dwarf disease and the stripe disease, intercrosses among Kanto PL 2, Kanto PL 3, Mineyutaka and Nipponbare were made. Kanto PL 2 is a parental line of japonica type rice resistant to the brown planthopper, and has Bph 1 gene derived from Mudgo. On the other hand, Kanto PL 3 is a japonica parental line resistant to the dwarf disease, and has one dominant gene derived from Pe-bi-hun. These two lines are also resistant to the stripe disease. Mineyutaka is the first resistant cultivar to the stripe disease in Japan, and has St₂ⁱ gene derived from Modan. Firstly, based on the segregation of F₃ lines of the reciprocal crosses between Kanto PL 2 and Kanto PL 3, it was estimated that Bph 1 is independent of the gene for resistance to the dwarf disease in Kanto PL 3.