小麦种质对茎基腐病抗性评价及优异种质筛选

Evaluation of Chinese Wheat Germplasm Resources for Crown Rot Resistance

小麦茎基腐病是由镰孢菌侵染引起的一种世界性土传病害,近年来已严重威胁到我国小麦的安全生产。为筛选具有茎基腐病抗性的小麦种质资源,本研究采用孢子悬浮液浸种法,分别以国外抗病材料Sunco和中国品种陕253为抗病和感病对照,对670份我国小麦品种(系)进行了茎基腐病温室苗期抗性鉴定。结果发现,我国供试品种(系)感病材料(病情指数>30)所占比例达到84%,且包含多个近年来小麦生产中的主推品种,表明我国小麦品种总体抗性水平低是导致茎基腐病近年来发病频率与程度不断增加的重要原因之一。经多轮筛选,发掘获得15份抗病表现稳定、抗性水平与抗病对照Sunco相仿的材料。15份材料平均病情指数在10.9~19.4之间,其株高、抽穗期等农艺性状表现出较为丰富的变异,为我国小麦抗茎基腐病品种选育和抗性遗传研究提供了种质资源。

Crown rot caused by Fusarium species is a worldwide soil-borne disease in several crop species.In recent years,crown rot became a common threat in many wheat-growing regions in China.However,the reports on large-scale screening of crown rot resistant resources remain rare.In this study,670 Chinese wheat germplasms plus two genotypes Sunco and Shan253,which served as resistant and susceptible control,respectively,were evaluated for crown rot resistance at seedling stage under greenhouse conditions.The results showed that 84%of tested accessions were susceptible,including many widespread varieties that are deploying in farming practice.That implied a potential of the increasing incidence and degree of crown rot in China in future.Fifteen genotypes showed reliable moderate disease resistance as the resistant control Sunco in multiple rounds of selection,with an average disease index ranged from 10.9 to 19.4.Specifically,a variation on plant height and heading time was observed in those 15 genotypes.Thus,this study unlocked the diseased index of Fusarium crown rot in Chinese wheat cultivars,which will provide reference for wheat resistance breeding.