Genetic Analysis of Rice False Smut Resistance Using Mixed Major Genes and Polygenes Inheritance Model

To study the inheritance of the resistance to rice false smut [Ustilaginoidea virens (Cooke) Takahashi], a population of 157 recombinant inbred lines (RILs) of F10 derived from the cross between resistant cultivar IR28 (Oryza sativa supsp. indica) and susceptible landrace Daguandao (O. sativa supsp. japonica) was analyzed using the mixed major genes and polygenes inheritance model. The indicator of resistance was disease rate index scored based on percentage of infected grains, which was investigated 3 weeks after artificial inoculation. The results showed that the resistance to rice false smut was controlled by the mixed 2 major genes and polygenes model (model E-1–3). The 2 major genes had equivalent additive effect of 11.41, and their heritability was about 76.67%. The heritability of polygenes was about 22.86%. Both effects of major genes and polygenes should be considered in the resistance breeding to rice false smut.