半裸镰孢致病性及苜蓿品种间的抗病性研究

Study on the pathogenicity of Fusarium semitectum and disease resistance of alfalfa varieties

为探明半裸镰孢对接种后苜蓿种苗的致病性、筛选抗苜蓿根腐病的品种,本研究把4个来源地的9个半裸镰孢分离物接种于14个品种的紫花苜蓿种子,在接种后第14 d测定苜蓿幼苗的相对根长、相对苗高、相对发芽率和病情指数,评价不同苜蓿品种对半裸镰孢的抗病性及病原菌对苜蓿幼苗致病性的相互关系。结果表明:半裸镰孢菌株和苜蓿品种对相对根长、相对苗高、相对发芽率及病情指数均有显著的影响(P<0.05)。病原菌方面,从苜蓿品种THG-1中分离出来的半裸镰孢的致病性最强,从Aohan中分离出来的半裸镰孢的致病性最弱,从WL-323HQ、Sitel和Siriver中分离出来的半裸镰孢的致病性较强,从Reindeer、Legacy和LM400中分离出来的半裸镰孢的致病性较弱;苜蓿品种方面,Algonguin的抗病性最强,Phabulous的抗病性最弱,Verna、Victoria、Hunter river和Amerimultileaf的抗病性较强,WL-323HQ、Sanditi、Sandy和Amerilea721的抗病性较弱。

The objectives of this study were to explore the pathogenicity of Fusarium semitectum causing root rot of alfalfa seedlings,to access the disease resistance and tolerance levels of alfalfa varieties,and to provide scientific basis for variety selection and its disease control. Fourteen varieties of alfalfa were inoculated with 9 pathogen isolates isolated from roots of 9 alfalfa varieties from 4 locations. The relative root length,relative seedling height,relative germination rate and disease index were assayed at 14 days after inoculation. The results indicated that ： relative root length,relative seedling height,relative germination rate and disease index differed highly significantly among the 14 alfalfa varieties and 9 pathogen isolates（ P0.05）. The isolate from‘THG-1’exhibited the strongest pathogenicity,while the isolate from‘Aohan’showed the weakest pathogenicity. The isolates from ‘WL-323 HQ’,‘Sitel’and ‘Siriver’exhibited strong pathogenicity,while the isolates from‘Reindeer’,‘Legacy’and‘LM 400’showed weak pathogenicity. Alfalfa variety ‘Algonguin’showed the strongest resistance,while‘Phabulous’ exhibited the weakest resistance.‘Verna’,‘Victoria’,‘Hunter river’and‘Amerimultileaf’showed strong resistance,while‘WL-323 HQ’,‘Sanditi’,‘Sandy’,‘Amerilea721’exhibited low-level resistance.