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采用SSR分子标记技术对采自全国19个地区、不同年份的落叶松-杨栅锈菌Melampsora larici-populina(简称MLP)36个单孢子堆菌系的遗传多样性和种群遗传结构进行了研究。用5对SSR多态性引物共检测到62个观察等位基因(Na),有效等位基因数(Ne)为5.42-9.82,平均有效等位基因数为7.05。供试MLP样本在5个SSR位点上的多态性信息量(PIC)变化范围为0.64-0.89,平均值0.79。平均观察杂合度(Ho)、平均期望杂合度(He)分别为0.36和0.86,不同位点的Shannon’s信息指数(I)平均值为2.12。结果显示,中国MLP菌系具有丰富的遗传多样性。各MLP菌系群体间遗传分化系数(Fst)变化范围为0.22-0.39,平均值0.344,基因流(Nm)平均值为0.48,显示遗传变异主要出现在MLP菌系群内部(65.60%),尤其以采自天然林的菌系群最为明显,但各菌系群之间也存在着明显的遗传分化(34.40%)。在菌系地理群体水平上,Shannon’s信息指数、Nei’s遗传多样性指数(Nei’s)平均值分别为1.02和0.56,平均多态性位点数(Np)和多态位点百分率(PPL)分别为4.54和90.77%,反映出MLP地理群之间的遗传多样性较菌系群内部的遗传多样性低。依据菌系地理群之间的遗传距离(0.24-2.99),将供试的13个中国落叶松-杨栅锈菌菌系群分为4个类群:菌群Ⅰ由北京延庆、太白山厚畛子、秦岭火地塘和四川宝兴诸菌系组成;菌群Ⅱ由吉林长春、黑龙江哈尔滨与肇东、甘肃临夏和青海诸菌系组成;菌群Ⅲ由内蒙古呼和浩特、陕西周至和杨凌的菌系组成;菌群Ⅳ由陕西宝鸡天台山和太白山上白云菌系组成。
The genetic diversity and population genetic structure of 36 monospores of Melampsora larici-populina (MLP) collected from 19 regions and years in China were investigated using SSR molecular markers. A total of 62 observed alleles (Na) were detected using 5 SSR polymorphic primers. The number of effective alleles (Ne) was 5.42-9.82 and the average number of effective alleles was 7.05. The polymorphism information amount (PIC) of MLP samples at five SSR loci varied from 0.64 to 0.89 with a mean of 0.79. The average observed heterozygosity (Ho), average expected heterozygosity (He) were 0.36 and 0.86, respectively, and Shannon’s information index (I) was 2.12 at different sites. The results showed that China MLP strains have rich genetic diversity. The genetic variation coefficient (Fst) of each MLP strain ranged from 0.22 to 0.39, with an average of 0.344 and an average of 0.48 of the gene flow (Nm), indicating that genetic variation mainly occurred in the interior of the MLP strain (65.60%), especially However, there was also a significant genetic differentiation between the strains (34.40%). Shannon’s information index and Nei’s average genetic index (Nei’s) were 1.02 and 0.56, respectively. The average number of polymorphic loci (Np) and polymorphic loci (PPL) were 4.54 and 90.77%, which indicates that the genetic diversity among MLP geographies is lower than the genetic diversity within the colony. According to the genetic distance (0.24-2.99), the 13 Chinese larch - Populus euphylla strains were divided into four groups: the flora Ⅰ was composed of Yanqing in Beijing, Subfamily, Qinling Huoditang and Baoxing, Sichuan Province. The strain Ⅱ consisted of Changchun in Jilin, Harbin and Zhaodong in Heilongjiang, Linxia and Qinghai in Gansu, and the strain Ⅲ consisted of the bacteria in Hohhot, Inner Mongolia, Department of composition; flora Ⅳ Baoji from Shaanxi Tiantai and Taibai Mountains by the Department of Phytophthora composition.