辽五味根腐病的病原菌鉴定与室内药剂筛选

Identification of the Pathogenic Bacteria of Root Rot of Schisandra chinensis in Liaoning Province and Fungicide Screening in Laboratory

目的:明确辽五味根腐病病原菌种类,筛选防治有效药剂。方法:采用发病组织分离法对辽五味病原菌进行分离和纯化并进行致病性测定,确定菌株的致病性后,运用形态学、分子生物学方法鉴定,明确病原菌种类;采用菌丝生长速率测定法测定10种药剂对该菌菌丝生长的抑制效果,进行室内毒力测定并建立毒力回归方程。结果:从采集的辽五味病株根部中分离纯化得到菌株,通过病原菌形态结合rDNA-ITS和EF-1α序列比对分析,确定致病菌为尖孢镰刀菌Fusarium oxysporum。室内药剂毒力测定试验结果显示10种药剂对病原菌都有不同程度的抑制效果;其中25%嘧菌酯和25%吡唑醚菌酯抑菌效果最好,其EC_(50)值分别为0.0033μg/mL和0.0956μg/mL。结论:确定辽五味根腐病致病菌为尖孢镰刀菌Fusarium oxysporum,防治的最佳药剂为25%嘧菌酯和25%吡唑醚菌酯。

Objective:To identify the pathogenic bacteria of root rot of Schisandra chinensis in Liaoning province and select effective agents for the prevention and treatment.Methods:The pathogenic bacteria of Schisandra chinensis in Liaoning province was isolated and purified by pathogenic tissue separation method and its pathogenicity was determined.After determining the pathogenicity of the strain,morphological and molecular biological methods were used to identify and determine the types of pathogenic bacteria.The hypha growth rate assay was used to determine the inhibition effect of 10 agents on the hypha growth,the toxicity was measured in the laboratory and the toxicity regression equation was established.Results:The strains were isolated and purified from the roots of the strain of Schisandra chinensis in Liaoning province,the pathogenic bacteria was identified as Fusarium oxysporum by the combination of morphology of pathogenic bacteria with rDNA-ITS and EF-1αsequence comparison.The laboratory toxicity test results showed that all the 10 agents had different inhibitory effects on pathogenic bacteria.Among them,25%azoxystrobin and 25%pyraclostrobin had the best antibacterial effect,and the EC_(50)values were 0.0033μg/mL,0.0956μg/mL,respectively.Conclusion:The pathogenic bacteria of root rot of Schisandra chinensis in Liaoning province is Fusarium oxysporum and the best agents for the prevention and treatment are 25%azoxystrobin and 25%pyraclostrobin.