关键词: 水稻白叶枯病菌, 高海拔粳稻, 地理区域, 品种, 致病力差异

Abstract:

The present situation of rice bacterial blight in the high altitude japonica rice region of Yunnan province were more and more serious. In order to find out the pathogenicity difference of the pathogen Xanthomonas oryzae pv.oryzae（Xoo）and effective prevention and control of bacterial leaf blight. 15 Xoo different varieties were used to analyze the difference in pathogenicity and resistance of the 32 strains collected from 11 rice varieties with the altitude over 1 800 m. The results indicated that pathogenicity of CX28-3 and CX30-1 from Chuxiong county were the most toxic, with the pathogenicity rate of 73.33%. The percentage of pathogenicity of JC12-2 was 0, which is the weakest. In the high altitude japonica rice area, the pathogenicity differentiation of Xoo isolates were not related to the altitude of the collected sites, but it was related to the geographical distance and the planting area of rice of collected isolates. There is no correlation among the pathotype frequency of Xoo isolates and altitude, except latitude and longitude of collected sites, and planting area of rice of the collected Xoo isolates. The rice varieties included Haonuoyang, IRBB14（Xa14）, IRBB4（Xa4） had high resistance to all the 32 strains. The resistance genes of them were worth of utilization and extension in Yunnan. In particular, Haonuoyang carris the new resistance gene, we should strengthen its localization and cloning in order to provide a new source of resistance.

Key words: Xoo, japonica rice in high altitude area, geographical area, variety, pathogenicity difference