Identification and Genetic Analysis of Gall Midge Resistance in Rice Germplasm 91-1A2

Resistance to rice gall midge in rice germplasm 91-1A2 was identified and genetically analyzed. F1s of rice population were derived from 91-1A2 which crossed with rice materials Jinggui, TN1, W1263 (Gm1), IET2911 (Gm2), BG404-1 (gm3), OB677 (Gm4), ARC5984 (Gm5) and Duokang 1 (Gm6) as a male parent. The resistance of all parental lines and F1, BC1F1 and F2 populations to rice gall midge was identified. The results showed that 91-1A2 and all F1s were resistant to Chinese rice gall midge biotype IV. The segregation ratio of resistant plants to susceptible ones in BC1F1 and F2 were accorded with 1:3 and 9:7 rules by X2 test, suggesting that the resistance of 91-1A2 to Chinese rice gall midge biotype IV was controlled by two dominant genes which were new resistance genes, non-allelic to the known rice gall midge resistance genes.