西藏林芝与内地小麦条锈菌分子群体遗传结构及菌源关系

 2009-2010年春季,先后从甘肃、四川、陕西和西藏四省的29个县(市)采集到1 391份小麦条锈病标样,繁殖获得961个菌株,利用SSR分子标记进行群体遗传分析结果表明:甘肃天水、平凉和陇南,陕西宝鸡及汉中,四川阿坝和广元等地条锈菌的遗传多样性比较丰富,而四川宜宾及凉山、西藏林芝的遗传多样性水平相对较低。利用Arlequin软件中的AMOVA方法分析结果表明,小麦条锈菌的遗传变异主要存在于群体内部。内地各种群之间菌源交流频繁(Nm＞4),西藏与内地菌源交流很少(Nm＜1)。采用Structure及聚类分析表明,陕西宝鸡与甘肃平凉间,陕西汉中、甘肃陇南、甘肃天水及四川广元间,存在着频繁的菌源交流关系,四川宜宾和凉山与四川阿坝、陕西汉中和甘肃陇南间存在着菌源交流关系。而西藏与内地间几乎没有菌源交流。初步认为西藏林芝小麦条锈菌可能是一个相对独立的遗传群体。

Molecular population genetic structure and migration relation of Puccinia striiformis f. sp. tritici between Linzhi in Tibet and inland

One thousand and three hundred ninety one wheat stripe rust samples were collected from 29 counties in Gansu, Sichuan, Shaanxi, and Tibet, China during spring of 2009-2010. Nine hundred and sixty one isolates of Puccinia striiformis f. sp. tritici were recovered from those samples. Population genetic diversity of the P. striiformis f. sp. tritici population containing 961 isolates was investigated with SSR technique. The results demonstrated that the genetic diversity of Tianshui, Pingliang and Longnan populations in Gansu, and Aba, Guangyuan populations in Sichuan was much higher than that in other regions. However, the genetic diversity of Yibin, Liangshan in Sichuan, and Linzhi in Tibet was lower than that in other regions. AMOVA of SSR was carried out using Arlequin software. Results showed that main genetic variation presented mainly within populations. Populations in inland (Gansu, Shaanxi, and Sichuan) had extensive gene exchange (Nm>4), and little gene exchange was found between Tibet and inland (Nm<1). The Structure and cluster analysis also indicated that there was almost no gene exchange between Tibet and inland populations. The frequent gene exchange was found between populations of Baoji in Shaanxi and Pingliang in Gansu, among populations of Hanzhong in Shaanxi, Longnan and Tianshui in Gansu, and Guangyuan in Sichuan. There was a certain gene exchange among populations of Yibin and Liangshan in Sichuan with Aba in Sichuan, Hanzhong in Shaanxi, and Longnan in Gansu. We preliminary argue that the population of P. striiformis f. sp. tritici in Tibet may be an independent from other populations under study.