紫花苜蓿镰刀菌根腐病抗病种质资源筛选

Evaluation of Alfalfa(Medicago sativa L.)Germplasm Accessions Resistance to Fusarium Root Rot

紫花苜蓿根腐病是我国苜蓿产区普遍发生的病害之一,其主要致病病原为尖孢镰刀菌。采用水培接菌法接种尖孢镰刀菌,测定58份供试苜蓿材料的病情指数、株高、根长、地下生物量并进行相关分析和聚类分析,评价紫花苜蓿种质材料苗期根腐病抗性。结果表明,株高、根长、地下生物量与病情指数均呈负相关。病情指数变化范围为12.50~70.83,根据病情指数共划分出4个不同抗性等级,分别是抗病材料、耐病材料、感病材料和高感材料。其中,抗病材料共1份,耐病材料共22份,感病材料共25份,高感材料共10份。根据聚类分析结果显示,58份紫花苜蓿材料大致分为可分为三类,分别为15份耐病材料、24份感病材料和19份高感材料。虽然部分材料与病情指数划分结果不是完全一致,但抗病材料和感病材料在聚类分析结果中能够被明显区分。其中,不同分析方法都表明,PAMPA为抗病材料,阳高、甘农3号、新牧2号、龙牧1号、CF030056、狼山、北疆、敖汉、偏关、G 13608都为高感材料,没有对根腐病完全免疫的种质材料。

Fusarium root rot is mainly caused by Fusarium oxysporum,which is one of common disease in alfalfa producing areas in China.In order to screen alfalfa germplasm accessions resistant to fusarium root rot,Fifty-eight alfalfa germplasm accessions were selected to inoculate F.oxysporum under improved hydroponics condition.The disease index,plant height,root length and root dry weight of the tested materials were analyzed by correlation and cluster analysis,and the resistance of alfalfa germplasm accessions to fusarium root rot at seedling stage was evaluated.The result indicated that plant height,root length and root dry weight were negatively correlated with disease index.The disease index ranged from 12.50 to 70.83.According to the disease index,four different resistance grades were divided,1 disease-resistant material,22 disease-tolerant materials,25 disease-susceptible materials and 10 high-susceptible materials.According to the results of cluster analysis,58 alfalfa materials could be roughly divided into three categories:15 disease-tolerant materials,24 disease-susceptible materials and 19 high-susceptible materials.Although the resistance grades of some materials were not completely consistent with the classification results of disease index,the disease-resistant materials and disease-susceptible materials could be clearly distinguished in the results of cluster analysis.Different analysis methods showed that‘PAMPA’was disease-resistant material,‘Yanggao’,‘Gannong No.3’,‘Xinmu No.2’,‘Longmu No.1’,‘CF030056’,‘Langshan’,‘Beijiang’,‘Aohan’,‘Pianguan’,‘G 13608’were high-susceptible materials,and there was no alfalfa germplasm accession completely immune to root rot.