八角炭疽病病原鉴定及防治药剂初筛

Pathogen identification and screening of fungicides for anthracnose of Illicium verum

为明确云南省富宁县经济作物八角上发生的炭疽病的病原,并初步筛选适用于防治该病的药剂,在室内开展了相关研究,先以组织法对富宁县发生炭疽病的八角样本进行真菌分离,经单孢纯化后,以柯赫氏法则验证分离菌的致病性,再结合形态学观察和多基因序列分析法鉴定病菌种类,并采用拮抗法评价8种常用杀菌剂对其的室内毒力。研究发现,以分离所得真菌(菌株编号T201)回接健康的八角叶片,能产生炭疽病典型症状,该菌的形态与松针刺盘孢菌(Colletotrichum fioriniae)一致,序列分析结果显示两者亲缘关系较高,由此认为富宁县八角炭疽病的病原菌是松针刺盘孢菌。在供试杀菌剂中,戊唑醇、咪鲜胺和多·锰锌对T201的菌丝生长具有较好的抑制作用,抑制中浓度EC50分别为2.62、2.72、2.79 mg/L,可作为八角炭疽病田间防治的备选药剂。

The objective of this study was to identify the pathogen of anthracnose on the economic crop Illicium verum in Funing County,Yunnan Province,and to preliminarily screen the candidate agents for field control of the disease.This was achieved through the isolation and purification of the fungi using the tissue isolation method and the single spore method.The pathogenicity of the isolated fungi was verified according to Koch’s postulates,and the species of pathogenic fungi were identified by morphological observation and multi-gene sequence analysis.The laboratory efficacy of eight commonly used fungicides was evaluated by antagonism method.The results showed that the isolated strain T201 could produce the typical symptoms of anthracnose in the field,exhibiting morphological characteristcs consistent with those of Colletotrichum fioriniae.Furthermore,the sequence analysis showed a high degree of relatedness between the two.It was concluded that C.fioriniae was the pathogen responsible for aniseed anthracnose in Funing County.Among the fungicides tested,pentazolol,imidamine,and polymanganese zinc had the most promising inhibitory effects on the mycelial growth of strain T201,with EC50 values of 2.62 mg/L,2.72 mg/L,and 2.79 mg/L,respectively.These fungicides could be considered as potential candidates for field control of aniseed anthracnose.