Abstract:

In order to compare the differences of resistance to rice blast disease in Yunnan among japonica rice cultivars collected from 17 provinces, and to screen favorable resistant resources of rice, we employed the method of natural induction in field blast nursery to assess the resistance of 1050 japonica rice cultivars against leaf and panicle blast. The results indicated that among the 1050 japonica rice cultivars, there was lighter incidence of leaf blast and more severe incidence of panicle blast. Regarding leaf blast resistance, the cultivars exhibiting high resistance, resistance, moderate resistance, moderate susceptibility, susceptibility, and high susceptibility accounted for 28.48%, 10.95%, 9.14%, 19.24%, 20.00%, and 12.19%, respectively. As for panicle blast resistance, the cultivars exhibiting high resistance, resistance, moderate resistance, moderate susceptibility, susceptibility, and high susceptibility accounted for 3.71%, 0.38%, 2.57%, 19.62%, 22.57%, and 51.14%, respectively. Further analysis of the leaf and panicle blast results revealed that 69 japonica rice cultivars had resistance to both leaf and panicle blast. These 69 cultivars were collected from five provinces of Jilin, Heilongjiang, Liaoning, Yunnan, and Jiangsu. These results suggested that these cultivars with good resistance against both leaf and panicle blast in blast nursery could be served as important resistance resources for blast disease-resistant rice breeding, and discovery of new genes conferring resistance to rice blast.

Key words: japonica rice cultivars, rice blast, resistance, evaluation, leaf blast, panicle blast, breeding resources