肉桂枝枯病病原的分离、鉴定以及室内药剂筛选

Isolation,Identification and Indoor Fungicides Screening of the Pathogen for Cinnamomum cassia Twig Blight

为明确广东罗定地区肉桂枝枯病的病原,筛选出防治肉桂枝枯病的最佳化学药剂,研究采用组织分离法分离病原菌,同时借助形态学、分子生物学和致病性测定相结合的方法鉴定其病原,进一步采用菌丝生长速率法测定8种供试杀菌剂对肉桂枝枯病菌的室内毒力。研究结果表明,广东罗定地区肉桂枝枯病的病原为假可可毛色二孢Lasiodiplodia pseudotheobromae;室内药剂毒力测定结果表明,98.4%多菌灵对肉桂枝枯病菌的抑制效果最好,在终浓度12.5μg·mL^(-1)时抑制率可达96.4%,其次是98%溴菌腈、97%吡唑醚菌酯和98%福美双,EC_(50)值分别为17.7、17.9和37.6μg·mL^(-1),其他药剂的EC_(50)值均大于40μg·mL^(-1)。综上所述,肉桂枝枯病的病原为假可可毛色二孢,98.4%多菌灵、98%溴菌腈、97%吡唑醚菌酯和98%福美双可作为防治肉桂枝枯病菌的杀菌剂进行林间防效试验。

To clarify the pathogen of Cinnamomum cassia twig blight in Luoding,Guangdong province and screen out the best chemical fungicide for controlling C.cassia twig blight,the pathogen was isolated by tissue isolation method,and the pathogen was identified by morphology,molecular biology and pathogenicity determination.The indoor toxicity of eight fungicides to the pathogen of C.cassia twig blight was determined by the mycelial growth rate method.The result showed that the pathogen of C.cassia twig bligh in Luoding,Guangdong province was Lasiodiplodia pseudotheobromae;the results of the indoor fungicide toxicity test showed that 98.4%carbendazim had the best inhibitory effect on L.pseudotheobromae,and the inhibition rate up to 96.4%at the final concentration of 12.5μg·mL^(-1),followed by 98%bromothalonil,97%pyraclostrobin and 98%thiram,with EC_(50) values,were 17.7,17.9 and 37.6μg·mL^(-1),respectively.The EC_(50) values of other fungi cides were greater than 40μg·mL^(-1).In summary,the pathogen of C.cassia twig blight is L.pseudotheobromae.98.4%carbendazim,98%bromothalonil,97%pyraclostrobin and 98%thiram can be used as fungicides to control C.cassia twig blight for forest field control experiments.