【摘要】 自1983年起,比较系统地对稻瘟病菌生理小种时、空间分布及变化规律进行观察。在时间上,主要对早稻病菌田间小种消长规律进行观察;在空间上,主要对山区各不同海拔的小种分布进行观察。通过对350个单孢菌株的测定.认为生理小种优势种群与优势小种在该病流行期基本保持稳定,优势小种组成与品种栽培面积及不同海拔品种布局有关;田间小种变化速率与气候条件有关。高山区引进品种抗性丧失快的主要原因是气候因子。更多还原

【Abstract】 Since 1983,the rule of changing of rice blast races relating to time and space has been observed.By testing about 350 single—spore isolates,the results showed that the dominant racewas keeping stable during epiphytotics and it related to the area of cultivated varieties and the distribution of them at different altitude.The rate of racial changing in fields was closely related tothe climate.The main cause for the loss of varietal resistance should be attributted to the altitudeand climatical factors.更多还原