小麦纹枯病品种抗性鉴定技术及抗病资源的筛选与分析

SCREENING TECHNIQUES AND EVALUATION OF WHEAT RESISTANCE TO SHARP EYESPOT CAUSED BY RHIZOCTONIA CEREALIS

分别用玉米粉-砂、麦粒和玉米秸秆作为小麦纹枯菌生长基质,培养获得小麦纹枯病菌接种物。土壤接种诱发试验表明,三种接种物在合适的接种强度下,均能有效诱发小麦纹枯病。据此建立的人工病圃对15份小麦材料的多年连续鉴定结果表明,病圃具有较稳定的发病率,表现为典型的尖眼点或云纹病斑。对我国主要冬麦区的1300份小麦品种资源、生产品种以及新育成品系进行了病圃鉴定,共筛选出抗纹枯病材料85份,包括菜籽黄、紫秆子、白贵农10号、Niavht、荆州黑麦、匈牙利核质杂种等国内外品种资源52份,宁9415、宁96260等育成品种(系)33份。而目前生产上大面积应用或即将推广的小麦品种多为感病品种,如扬麦158、宁麦8号、扬93-111、扬96G25、徐州25等。

Sharp eyespot of wheat is one of the most important diseases causing severe yield loss in Yangtze River and Huanghe River Region of China. Cultivation of resistant varieties would be the most effective and economical method to control the disease. Unfortunately there are no practical resistant cultivars and even no resistant parent materials. It s necessary to study the screening techniques for evaluating sharp eyespot resistance and selecting resistant germplasm materials. In this study, the causal agent of wheat sharp eyespot, Rhizoctonia cerealis , was cultured on media of corn meal with sand, wheat grains and com straw. The culture was mixed with soil in the field and then wheat was planted in it. Wheat was infected in suitable inoculation intensity. The disease nursery was established with this method and had constant disease occurrence in three-year trials. More than 1300 wheat lines were screened for the resistance in the nursery from 1995 to 1997. Of them 85 were resistant, such as Caizhihuang, Haizhouhongheshan, Huaiyingdabaili, Baiguinong 10, Gam-pair, Niavht and Lingpuzhao. Most commercial varieties and those will be released in near future were susceptible, including Yangmai 5, Yangmai 158, Yangmai 93-111, Ningmai 8, Yang96G27, Yang 96G25, Xuzhou 24, Xuzhou 25.