云南高海拔粳稻区白叶枯病菌致病力差异分析

云南高海拔粳稻区白叶枯病危害日益严重,为了探明该区域白叶枯病菌致病力差异,对白叶枯病进行有效防控。利用15个水稻白叶枯病菌鉴别品种,对采集自海拔1800 m以上稻区11个水稻品种上的32份菌株进行致病力研究。结果发现,致病力最强的菌株是楚雄州的CX28-3和CX30-1,致病率为73.33%;最弱的是大理州剑川县的JC12-2,致病率为0。在高海拔粳稻区,菌株的致病力分化与采集地的海拔高度无关,却与地理距离、采集品种的推广面积有关;而菌株的致病型频率与其采集地的海拔、经纬度、采集品种的推广面积的相关性均不显著。鉴别品种毫糯扬(含新基因)、IRBB14(Xa14)、IRBB4(Xa4)和Tetep(Xa2,Xa16)对所有参试菌株表现为高抗或抗。因此,这些品种内所含的抗性基因值得在云南高原粳稻育种和生产中应用,特别是云南地方稻种毫糯扬,更应加强其新抗病基因的定位和克隆,以为品种选育提供新的抗原。

Analysis on Pathogenicity Difference of Xanthomonas oryzae pv.oryzae from Japonica Rice in High Altitude Region in Yunnan Province

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.