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为明确四川西南部白粉菌群体毒性及其遗传变异情况,本文将2011年采自四川西南部的小麦白粉病标样进行单孢子堆分离纯化,共获得48个白粉菌菌株,并将其按采集地划分为4个地理群体。利用28份已知抗白粉病基因材料测定了群体的毒性频率,并运用SRAP分子标记技术探讨了其遗传多样性。毒性测定结果表明,白粉菌群体毒性较强,群体间毒性结构存在差异。供试群体对Pm1、Pm3a、Pm3b、Pm3d、Pm5a、Pm6、Pm19的平均毒性频率达50%以上,而Pm13、Pm XBD、Pm5b、Pm2+6、Pm5+6抗性保持良好,平均毒性频率在10%以下。群体间毒性遗传距离与地理距离之间有一定的相关性,但未达到显著水平。用筛选出的10对SRAP引物共获得160个清晰、稳定的扩增位点,多态性频率为50.63%;白粉菌群体遗传多样度(h)、Shannon信息指数(I)分别为0.198 8、0.322 7,遗传变异主要源于群体内部。群体间基因流数值均在6.50以上,说明四川西南部白粉菌群体间菌源迁移频繁,基因交流较为充分。M antel Test分析表明SRAP标记解释的群体遗传多样性与地理距离、毒性多样性间的相关性未达到显著水平。
In order to clarify the population toxicity and genetic variation of powdery mildew in the southwestern Sichuan Province, 48 powdery mildew strains were isolated and purified from the powdery mildew samples of wheat powdery mildew in southwestern Sichuan province in 2011, Divided into 4 geographical groups. Twenty eight known powdery mildew resistant genes were used to determine the frequency of virulence and their genetic diversity was explored using SRAP molecular markers. Toxicity test results showed that the powdery mildew population was highly toxic and there were differences in the toxic structures among the populations. The average frequency of toxicity of Pm1, Pm3a, Pm3b, Pm3d, Pm5a, Pm6, Pm19 was above 50%, while the resistance of Pm13, Pm XBD, Pm5b, Pm2 + 6 and Pm5 + 6 was well maintained. The average frequency of toxicity Below 10%. There was a certain correlation between the genetic distance and geographical distance between groups, but it did not reach the significant level. A total of 160 clear and stable amplification loci were obtained with 10 pairs of SRAP primers screened out, and the frequency of polymorphism was 50.63%. The genetic diversity (h) and Shannon information index (I) of powdery mildew were 0.198 8, 0.322 7, genetic variation mainly from within the group. Gene flow values among populations were all above 6.50, indicating that the fungal sources in the southwestern Sichuan Mijing frequent migration, gene exchange more fully. Analysis by M antel Test showed that the correlation between population genetic diversity explained by SRAP marker and geographical distance and toxicity diversity did not reach significant level.