苜蓿根腐病病原菌分离鉴定与抗病种质材料筛选

Isolation and Identification of Pathogenic Fusarium of Alfalfa Root Rot and Screening of Disease-resistant Germplasm Materials

在黑龙江省大庆市采集具有典型苜蓿根腐病症状的发病植株进行病原分离、纯化,根据形态学和rDNA-ITS序列分析进行鉴定,确定分离获得的苜蓿根腐病病原菌为层出镰刀菌(Fusarium proliferatum)。对来自国内外具有较强抗寒性的16个紫花苜蓿品种芽期接种病原菌菌株,于接种后第14d测定紫花苜蓿幼芽的相对根长、相对苗长和病情指数,利用隶属函数值对不同品种苜蓿进行抗病性综合评价。结果表明,层出镰刀菌接种后,各紫花苜蓿品种幼芽的相对根长、相对苗长及病情指数差异显著(P<0.05);根据隶属函数值评价结果,品种WL168HQ、TG4、斯贝德和肇东的综合抗病性表现较强,DS310FY、北极星、皇后、WL319HQ和巨能-CR的综合抗病性较弱。

Diseased plants with typical symptoms of alfalfa root rot were collected in Daqing city,Heilongjiang province for pathogen isolation and purification.The pathogen of alfalfa root rot was identified as Fusarium proliferatum by morphology and rDNA-ITS sequence analysis.Sixteen alfalfa cultivars with strong cold resistance from domestic and abroad were inoculated with pathogenic fusarium at germination stage.The relative root length,relative seedling length and disease index of alfalfa germination was determined on the 14 th day after inoculation.The disease resistance of different alfalfa varieties was evaluated comprehensively by membership function.The results showed that there were significant differences(P<0.05)in relative root length,relative seedling length and disease index among different varieties after inoculation with F.proliferatum.According to the evaluation results of subordinate function values,WL168 HQ,TG4,Spyder and Zhaodong showed strong comprehensive disease resistance among all varieties,while the comprehensive disease resistance of DS310 FY,Northstar,Queen,WL319 HQ and Juneng-CR was relatively weak.