三种杀菌剂对浙江省玉米大斑病菌的毒力测定及两种药剂的复配比例筛选

本试验采用抑霉唑、烯唑醇、多菌灵三种杀菌剂分别对浙江省内采集到的58株玉米大斑病菌进行毒力测定。测定结果表明,多菌灵对58株玉米大斑病菌的毒力变化差异最小,抑霉唑次之,烯唑醇的毒力变化差异最大;三种药剂相比较,毒力差异极显著,抑霉唑毒力最高,烯唑醇次之,多菌灵最低。将抑霉唑与烯唑醇进行复配比例筛选,结果表明,抑霉唑与烯唑醇质量比为1:5时,共毒系数最高,具有很好的增效作用。     

四川西南部小麦白粉菌群体毒性及遗传多样性分析

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。     

玉米大斑病菌人工接种方法研究

 The efficient and accurate method of inoculating Exserohilum turcicum on maize is most important for studying the corn leaf blight. In this study, four approaches including spore suspension spraying, inoculation with grinding infected maize leaves, inoculation liquid inoculum into the leaf whorl and inoculation with inoculated sorghum seeds were compared with natural induction in fields during different growth stages of maize in the greenhouse and field. The results showed that disease incidence of all varieties tested were up to 100% by inoculating with inoculated sorghum seeds during the booting stage (11 to 12 leaf stages). This method will not only guarantee the enough pathogen inocula but also be easy to use, and could be an effective way for disease resistance identification in field and greenhouse.      

四川玉米大斑病发生情况及其防治措施

玉米大斑病是严重为害玉米生产的叶斑病害,近年来在四川省玉米生产中的为害日益加重.为有效防治该病,笔者就该病的发生原因、影响发病的条件,以及四川省主要发生区域、为害情况及防治方法等作一介绍.