玉米弯孢叶斑病菌生理分化及鉴定技术

 从我国20余个主栽玉米品种和20个骨干自交系中筛选出沈135、78599-1、Mo17、477、C8605、E28、7922和黄早4等8个自交系,作为鉴别寄主来研究弯孢叶斑病菌的生理分化。研究表明,弯孢叶斑病菌[Curvularia lunata(Wakker) Boed.]在温室进行的苗期鉴定与田间成株期鉴定的生理分化结果一致。苗期鉴定具有操作简单、鉴定环境条件易控制等特点。通过8个鉴别寄主将采自我国玉米产区的20株弯孢叶斑病菌分为6个致病类型,其中类型A致病性强、分布广,为优势致病类群;类型D主要分布在我国零星发生的地区,为弱致病类群。同时研究了影响病菌生理分化鉴定的主要环境因子,其中湿度、温度和植株营养状况对病菌生理分化鉴定结果有明显影响。本研究结果为我国玉米品种抗性鉴定、弯孢菌叶斑病流行监测和品种合理布局提供了理论依据。

Identification techniques for physiological differentiation of Curvularialunata in maize

Eight inbred lines were selected from more than 20 dominant maize cultivars and 18 major inbred lines asdifferential hosts to identify the physiological differentiation of Curvularia lunata, they were Shen135, 78599-1, Mo17,477, C8605, E28, 7922 and Huangzao 4. The identification of physiological differentiation during seedling period in green-house was consistent with that in adult period, so identification in seedling period was selected as a most effective methodsince it was easily operative and easy to control environmental factors. Twenty isolates of Curvularia lunata were identifiedin 8 differential hosts as 6 pathogenic differential types in which type A with higher pathogenicity was distributed widely inheavily-occurring areas, however, type D with weak pathogenicity was distributed in less-occurring area, therefore type Acould be considered as the dominant pathogenic group. Other major factors such as humidity, temperature and nutrition, tosome extent, influencing identification of physiological differentiation were also investigated, and which produced some re-markable effect on identification of physiological differentiation of pathogen by the mentioned factors. The result mentionedabove provided a sound basis for breeding and identification of resistant cultivars, reasonable distribution of resistant culti-vars and monitoring of pathogen differentiation.