云南元阳哈尼梯田稻瘟病菌遗传多样性分析

 利用12对SSR引物,对来自云南元阳哈尼梯田不同海拔高度、不同水稻品种上的稻瘟病菌菌株进行遗传多样性分析,并运用日本清泽建立的鉴别品种对其中62个菌株进行生理小种鉴定。结果显示:稻瘟病菌总体遗传多样性水平较高(He=0.57±0.27,I=1.17±0.60)。聚类分析表明,在80%相似水平下菌株可划分为9个多样性群体。供试菌株划分为16个生理小种,其中002、000和006为优势小种。分离的不同海拔稻瘟病菌生理小种和遗传多样性存在差异。海拔1600~1700m生理小种最丰富,达9个生理小种;海拔1500~1600m、1400~1500m和1700~1800m,生理小种分别为6、5和4个;遗传多样性分析表明,从海拔1400~1500m分离的菌株遗传多样性水平最高(He=0.57±0.24),并划分为6个群体。综合分析表明,在元阳哈尼梯田系统中,栽培传统品种遗传多样性越丰富的区域,其稻瘟病菌群体多样性和生理小种也越丰富。

Genetic diversity of Magnaporthe grisea of Hani terrace from Yuanyang county in Yunnan

To determine the genetic diversity and physiological races of the rice blast fungus from Hani terrace of Yuanyang county in Yunnan province, simple sequence repeat (SSR) markers were used to estimate the genetic diversity of isolates of Magnaporthe grisea. Sixty-two isolates were studied for physiological races by using the standard differential variety sets developed in Japan for blast resistance in rice. Genetic diversity of rice blast fungus was analyzed with the unweighted pair-groups method using arithmetic averages (UPGMA) method of cluster analysis. Two-hundred isolates were divided into 16 physiological races, 000, 002 and 006 among them were found to be dominant races. The overall genetic diversity of rice blast fungus from Hani terrace of Yuanyang county observed in this study was relatively high (He=0.57±0.27, I=1.17±0.60). All isolates were classified into 9 genetic lineages at 0.20 linkage distance level. It was also noticed that genetic diversity of rice blast fungus also varied with altitude. There were 9 races between 1 600 m and 1 700 m in altitude and highly genetic diversity of rice blast fungus populations was observed at the range of 1 400 to 1 500 m (He=0.57±0.24). The data strongly suggested that there are significant positive correlations between genetic varieties of rice blast fungus and the traditional rice varieties cultivated over decades in Yuanyang Hani terrace.