Genetic analysis of resistance to green leafhopper, Nephotettix virescens (Distant), in IR rice varieties

The genetics of resistance to green leafhopper (GLH), Nephotettix virescens (Distant), in 22 IRRI-bred rice varieties was studied. These varieties were crossed with a susceptible (S) variety, Taichung Native-1 (TN1), and reaction to green leafhopper of F1 hybrids, F2 populations, and F3 lines was studied. Results revealed that single recessive (R) genes govern resistance in IR32, IR38, IR40, IR44, and IR46, while single dominant genes convey resistance in the remaining varieties. Allele tests with known genes for resistance revealed that dominant genes in IR5, IR20, IR30, and IR45 are allelic to Glh3. On the other hand, IR34, IR50, IR52, IR54, IR56, IR58, IR60, and IR65 have Glh9. The dominant genes in IR24, IR26, IR29, IR43, and IR48 and the recessive genes in IR32, IR38, IR40, IR44, and IR46 segregate independently from Glh1, Glh2, and Glh3. The allelic relationships of these genes with other known genes for resistance to GLH are not known