Abstract:

【Objective】 The objective was designed to compare the differentiating capacity of two sets of differential lines. 【Method】 A total of 418 blast monoconidial isolates collected from 27 counties of Yunnan Province were tested using two sets of differential varieties which hold nine different resistance genes. One set is Japanese differential varieties, another set contained two Japanese differential varieties and seven monogenic lines which developed using susceptible variety Lijiangxintuanheigu (LTH) as recurrent parent (IRBL lines). Both of them hold the same set of resistance genes. The differentiating capacity of IRBL lines to Yunnan isolates was compared with that of Japanese differential varieties. 【Result】 The result showed that the differentiating capacity of IRBL lines was better than Japanese differential varieties to rice blast fungus colleted from Yunnan. These monoconidial isolates were divided into 126 races based on the reactions to IRBL lines, while they were divided into 95 races using Japanese differential varieties. 【Conclusion】 The result indicated that the monogenic differential varieties with same genetic background are better than that of complex background.

Key words: Magnaporthe grisea, race, differential varieties, monogenic resistant lines