香榧根腐病病原菌分离鉴定及绿色药剂筛选

<正>0 引言香榧(Torreya grandis cv. Merrillii)为我国特有的珍稀经济干果与重要木本油料作物^1],主要分布于浙江省诸暨、绍兴、临安等地^2],香榧产业发展迅速，已成为当地农业支柱产业和农民增收的主要来源^3]。近年来，多地香榧林出现根腐病且为害日益严重，成为影响香榧产业可持续发展的重要障碍之一。因此香榧根腐病病原菌鉴定与防治技术研发迫在眉睫。本论文通过组织分离法、单孢培养法获得纯菌种，

Pathogen identification of Torreya grandis root rot and green fungicides screening

To effectively control root rot of Torreya grandis, pathogenic fungi were obtained from the diseased roots of T. grandis by tissue isolation and single spore culture. Through pathogenicity detection, morphological observation and sequence analysis of ITS1, RPB1, RPB2 and TEF1, it was identified as Fusarium solani, which is the first reported pathogen of T. grandis root rot at home and abroad. Seven kinds of green fungicides were screened in the laboratory, among which 50% fludioxonil suspension, 50% azoxystrobin suspension emulsion, 3% mefenoxam aqueous solution and 10% jinggangmycin aqueous solution had strong fungicidal action against F. solani. The EC₅₀ of them were 0.094 9, 0.167 6 mg, 0.601 4 and 1.258 7 mg·L^-1, respectively. The results of field efficacy tests showed that the control effect of 3% mefenoxam against root rot of Torreya grandis is 55.75%, the highest among the four fungicides.