Abstract:To understand the distribution of rice blast resistant genes and their contribution to rice blast disease in Liaoning Province, We selected 176 rice varieties, and identified the distribution of rice blast resistance genes Pi21、Pi36、Pi37、Pita、Pid2、Pid3、Pi5 and Pib in these varieties. Meanwhile, the phenotypes of rice blast resistance of these varieties were studied by inoculating. The results showed that 83 varieties were resistant to rice blast disease, among them, the rates of cultivars, weedy rice and landraces were 41.48%、1.14% and 4.54%, respectively. Rice blast resistance genes Pi21、 Pi36 and Pi37 were not detected in all rice germplasm resources, and 49、 47、74、52 and 89 germplasm resources carried Pita、 Pid2、 Pid3、 Pi5 and Pib, respectively. Most of the genes were found in cultivars, but they were rare in landraces and weedy rice. Most of the varieties that have no any rice blast resistant genes and carry single rice blast resistant gene were susceptible to rice blast. Gene pyramiding could improve the resistant to some extent. In this test, about 32 varieties did not carry any rice blast resistance genes that we identified, and only 21.87% of which were resistant to rice blast; about 52 varieties carried single rice blast resistance gene, and only 17.31% of which were resistant to rice blast, too; about 39 varieties carried two rice blast resistance genes, and 69.23% of which showed resistant to this disease. Within them, 14 varieties that carried Pita and Pi5 all showed resistant to rice blast; about 31 varieties carried three rice blast resistance genes, among them, the germplasm resources that were resistant to rice blast accounted for 77.42%, and the resistance of varieties that carried Pita, Pid3 and Pi5 simultaneously are signally good; about 22 varieties carried four rice blast resistance genes, with 72.73% of which were resistant to rice blast; the varieties carried five rice blast resistance genes were not found.