不同地域和寄主来源的核盘菌遗传多样性分析

为了解核盘菌[Sclerotinia sclerotiorum（Lib.）de Bary]遗传多样性和进化关系,利用SSR分子标记对采自不同地区和寄主来源的32个核盘菌分离物进行分析,17对SSR引物共检测到69个多态性位点,平均每对引物检测到4.06个位点。其中,引物AF377908-1/AF377908-2和AF377922-1/AF377922-2的等位变异数目最多,高达8个,而引物AF377903-1/AF377903-2和AF377925-1/AF377925-2的等位变异数目最少,为2个。17个SSR引物的多态性信息量（PIC）的平均值为0.56,引物AF377922-1/AF377922-2的PIC最高,为0.78。聚类分析显示,32个核盘菌分离物可划分为5个组群,来自同一地区的大部分核盘菌分离物聚在相同或相近的组内,表明核盘菌群体内的SSR遗传背景基本一致,而群体间的遗传变异较大。

Genetic diversity of Sclerotinia sclerotiorum isolates from different regions and host plants by SSR markers

Sclerotinia stem rot caused by Sclerotinia sclerotiorum（ Lib.） de Bary has a wide host range. Genetic diversity of 32 isolates of S. sclerotiorum collected from different geographical regions and host plants were detected by SSR markers. A total of 69 alleles were observed using 17 pairs of primers with an average of 4. 06 alleles for each pair of primers. The alleles with the largest numbers（ 8） were found in 2 pairs of primers（ AF377908- 1 / AF377908- 2 and AF377922- 1 / AF377922- 2）,and the least number of alleles（ 2） occurred in the other 2 primer pairs（ AF377903- 1 / AF377903- 2 and AF377925- 1 / AF377925- 2）. The mean value of DNA polymorphic information content（ PIC） was 0. 56. The highest PIC value was 0. 78 detected with AF377922- 1 / AF377922- 2. In cluster analysis,32 isolates were divided into 5 groups. Most isolates from the same region were grouped in the same or a close population,suggesting that Sclerotinia genetic loci within populations were relatively consistent but significantly different among populations.