| 摘要: |
| 【目的】明确福建省玉米小斑病菌的致病力水平，为筛选抗病玉米品种及该病害的预测预报和防治提供依据。【方法】在玉米苗期采用喷雾接种法，以11个玉米品种为材料，以分离自福建省7个地区21个县（市）的298株玉米小斑病菌菌株的孢子悬浮液为接种体，先在感病玉米品种上品上进行菌株致病力测定，7 d后调查病情指数，从中选出致病力较强的菌株，采用同样方法接种其他玉米品种，分析菌株致病力差异。【结果】供试菌株对玉米感病品种上品均有致病性，病情指数介于13.50～80.95，平均值为49.49。根据致病力测定结果将菌株分为强、中、弱3种致病类型，各类型出现频率分别为29.87%,63.42%和6.71%，中等致病力菌株占优势。不同地区菌株致病力存在显著差异，以福州地区菌株致病力最高；同时福州地区来自玉米连作田的菌株比非连作田的菌株具有较高的致病力。不同菌株、甚至同一菌株在不同玉米品种上的致病力表现出丰富的多样性。供试的298个菌株中MH141和JY142致病力较强，供试的11个玉米主栽品种中榕甜1号和永珍7号抗病性较好。【结论】来自福建省不同地区的玉米小斑病菌对玉米的致病力存在明显的分化现象，不同菌株对同一玉米品种的致病力存在明显差异；同一菌株对不同玉米品种的致病力也存在明显差异。 |
| 关键词: 玉米小斑病 玉米小斑病菌 致病力分化 福建省 |
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| 基金项目:福建省自然科学基金项目（2016J05073）；福建省农业科学院青年科技英才百人计划项目（YC2016-4）；福建省农业科学院博士启动基金项目（2015BS-4）；福建省农业科学院植物保护创新团队项目（STIT2017-1-8） |
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| Pathogenicity differentiation of Cochliobolus heterostrophus in Fujian |
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DAI Yuli,GAN Lin,TENG Zhenyong,et al
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| Abstract: |
| 【Objective】Pathogenicity levels of Cochliobolus heterostrophus isolates in Fujian were determined to provide basis for corn variety selection as well as prediction and prevention of the isolates.【Method】A total of 11 corn varieties were used for testing materials and conidia suspensions of 298 C.heterostrophus isolates from 21 prefectures (cities) of 7 regions in Fujian province were served as inocula.Pathogenicity assays for different isolates were initially determinated on susceptible corn variety ‘Shangpin’ using the method of spraying conidia suspensions during corn seedlings.Disease index for each isolate was investigated after 7 d inoculation;the stronger pathogenic isolates were selected and inoculated on other corn varieties using the method as described above.The pathogenicity differentiation of tested isolates was analyzed in this study.【Result】All tested isolates had pathogenicity on corn variety Shangpin,and the disease indexes were 13.50 to 80.95 with average of 49.49.According to the pathogenicity results,C.heterostrophus isolates were roughly divided into weak,moderate and strong types with frequencies of 29.87%,63.42% and 6.71%,respectively.The moderate type was dominant.There were significant differences in pathogenicity of C.heterostrophus isolates from different regions,and the isolates from Fuzhou region had the strongest pathogenicity.The isolates from continuous corn cropping fields had significant higher pathogenicity than normal rotation cropping fields in Fuzhou.The pathogenicity of different isolates,even the same isolate exhibited abundant diversity among corn varieties.MH141 and JY142 had stronger pathogenicity and ‘Rongtian 1’ and ‘Yongzhen 7’ showed better resistance to C.heterostrophus among the tested 11 corn varieties.【Conclusion】The pathogenicity had significant differentiation in isolates of C.heterostrophus collected from different regions in Fujian.Different isolates had different pathogenicity to same variety and same isolate had different pathogenicity to different corn varieties. |
| Key words: southern corn leaf blight Cochliobolus heterostrophus pathogenicity differentiation Fujian |
