广西南宁火龙果溃疡病病原菌鉴定与室内药剂毒力测定

Identification of the Pathogen Causing Pitaya Canker Disease in Nanning and Toxicity Measurement in Laboratory

为明确广西南宁市火龙果溃疡病病原菌种类并筛选出防治效果较好的杀菌剂,从当地果园采集病样,以组织分离法分离和纯化病原菌,根据形态学特征和ITS序列分析对病原菌进行鉴定,并应用柯赫氏法则验证病原菌的致病性;采用菌丝生长速率法测定5种不同杀菌剂对该病原菌的室内毒力。结果表明:南宁市火龙果溃疡病病原菌为新暗色柱节孢Neoscytalidium dimidiatum,供试的5种杀菌剂对火龙果溃疡病病原菌菌丝生长均具有一定的抑制作用,其中70%春雷·王铜·噻锌水剂的抑菌效果最强,EC_(50)为0.1950 mg/L;其次为60%吡醚·代森联水分散粒剂和42%春雷·喹啉铜悬浮剂,EC_(50)分别为1.1570和1.1932 mg/L。本研究结果为火龙果溃疡病的防治提供了理论依据。

To clarify the pathogenic species of pitaya canker disease in Nanning and screen the fungicides with better prevention and control,the disease samples were collected from a local orchard,the pathogen was isolated and purified by tissue isolation method,and the pathogen was identified according to morphological characteristics and ITS sequence analysis and the pathogenicity of this pathogen was verified according to Koch's rule.In the meantime,the indoor virulence of five different fungicides against the pathogen was determined using the mycelium growth rate method.The results showed that the pathogen of pitaya canker in Nanning was Neoscytalidium dimidiatum,and all the five tested fungicides had some inhibitory effects on the mycelial growth of pitaya canker pathogen,among them,kasugamycin·copper-oxychloride·zinc-thiazole 70%AS had the best antibacterial effect with an EC_(50)of 0.1950 mg·L^(-1),followed by pyraclostrobin·metiram 60%WG with an EC_(50)of 1.1570 mg·L^(-1),and kasugamycin·oxine-copper 42%SC with an EC_(50)of 1.1932 mg·L^(-1).The research results provide a vital theoretical reference for the prevention and control of pitaya canker.