陕西省小麦白粉菌群体毒性结构及遗传多样性

为明确近年来陕西省小麦白粉菌Blumeria graminis f. sp. tritici群体毒性及遗传变异情况,利用32份已知抗白粉病基因小麦品种(系)对2013年和2014年陕西省小麦白粉菌群体毒性结构进行测定,并应用扩增片段长度多态性(amplified fragment length polymorphism,AFLP)标记对2014年陕西省西安市、咸阳市、渭南市、宝鸡市及陕西省毗邻的甘肃省天水市5个小麦白粉菌地理群体共118株白粉菌菌株进行遗传多样性分析。毒性监测结果显示,供试小麦白粉菌群体对Pm1c、Pm2、Pm3d、Pm4a、Pm4b、Pm5b、Pm13、Pm21、Pm24、Pm30、Pm2+6、Pm2+Mld、Pm2+6+?、Pm4b+5b、Pm4+?、Pm5+6的平均毒性频率在0～17.23%之间,表明这些基因抗性保持较好;对Pm1a、Pm3b、Pm3c、Pm3e、Pm3f、Pm7、Pm8、Pm19、Pm1+2+9的平均毒性频率介于69.17%～99.60%之间,表明这些基因抗性已丧失。用筛选出的6对AFLP标记共扩增出831个多态性位点,多态性位点百分比为94.86%;小麦白粉菌群体遗传多样性指数和香农信息指数分别为0.1151和0.2036,遗传变异主要来源于群体内变异。群体间基因流为4.7939,表明5个小麦白粉菌群体间基因交流广泛。群体间遗传距离和地理距离两者显著正相关。

Virulence and genetic diversity of Blumeria graminis f. sp. tritici collected from Shaanxi Province

To characterize the virulence and genetic diversity of Blumeria graminis f. sp. tritici (Bgt) population in Shaanxi Province, a total of 238 isolates collected from the province were tested against 32 wheat cultivars (lines) with known powdery mildew resistance genes in 2013 and 2014; the genetic diversity of 118 isolates from five geographical populations in Xi''an City, Xianyang City, Weinan City and Baoji City of Shaanxi Province and Tianshui City of Gansu Province was analyzed in 2014 with amplified fragment length polymorphism (AFLP) markers. The mean virulence frequencies of the resistance genes Pm1c, Pm2, Pm3d, Pm4a, Pm4b, Pm5b, Pm13, Pm21, Pm24, Pm30, Pm2+6, Pm2+Mld, Pm2+6+?, Pm4b+5b, Pm4+? and Pm5+6 were 0-17.23%, indicating that these genes were still effectively resistant to Bgt, whereas those of Pm1a, Pm3b, Pm3c, Pm3e, Pm3f, Pm7, Pm8, Pm19 and Pm1+2+9 were 69.17%-99.60%, suggesting that these genes had lost their resistance in Shaanxi Province. A total of 831 polymorphic bands were identified by six AFLP markers, with a diversity frequency of 94.86%. The Nei''s gene diversity and Shannon''s information index of Bgt populations were 0.1151 and 0.2036, respectively. The genetic variation of Bgt isolates mainly occurred within the population. The gene flow values of the five geographical populations were 4.7939, which indicated that the sufficient exchange of genes happened among these populations. Moreover, there was a significant positive correlation between their geographic distances and genetic diversity.