INHERITANCE OF BLAST RESISTANCE IN RICE

Abstract

The inheritance of resistance to blast was studied in seven rice cultivars, (BG 367-4, IRAT 102, IR 4547-6-2-5, Milyang 46, Secanado Brazil, Tetep and VL 8) crossed with two blast susceptible cultivars, VLK 39 and Thapachini. The FI, F2, BCI and BCz generations were raised and inoculated with the VLH-Kl isolate of Pyricularia oryzae Cay. at seedling stage. The resistance in 12 out of 15 crosses was found to be governed by a single dominant gene, while in the cross IR 4547-6-2-5 x Thapachini it was one dominant and one recessive gene. The cross between two resistant parents, Tetep and VL 8, showed allelic relationship, whereas the cross between the two susceptible cultivars, VLK 39 and Thapachini, showed that each cultivar carried a single but different recessive gene for resistance.