油茶炭疽病病原鉴定及绿色防治药剂筛选

Identification of Colletotrichum Species Associated with Anthracnose of Camellia oleifera and Screening of Fungicides

油茶炭疽病是我国油茶重要病害,为筛选出有效的防治药剂,本研究从我国油茶主产区采集具有典型症状的炭疽病病叶分离病原菌,结合病原菌形态特征和多基因系统发育分析对其进行了系统鉴定,并采用菌丝生长速率法测定病原菌对化学杀菌剂敏感性。结果表明,本研究分离出的17株油茶炭疽病菌均属于刺盘孢属胶孢复合群(Gloeosporioides complex)真菌,包括山茶刺盘孢Colletotrichum camelllae、果生刺盘孢Colletotrichumfructicola、暹罗刺盘孢Colletotrichumsiamense、胶孢刺盘孢Colletotrichum gloeosporioides、卡瓦刺盘孢Colletotrichum kahawae、哈锐刺盘孢Colletotrichum horri等。测试的13种杀菌剂中,油茶炭疽病菌对咪鲜胺药剂最敏感,平均EC_(50)值为0.035μg/m L;其次为氟啶胺、多菌灵、咯菌腈、吡唑醚菌酯、苯醚甲环唑、氟环唑、苯并烯氟菌唑和戊唑醇,平均EC_(50)依次为0.076、0.169、0.202、0.243、0.342、0.490、0.534和1.401μg/mL;此外,测试的油茶炭疽病菌对嘧菌酯、啶酰菌胺、氟醚菌酰胺和氟吡菌酰胺四种药剂均不敏感,平均EC_(50)值大于100μg/mL。

Anthracnose is one of the most common diseases of the tea-oil trees.In this study,isolates of Colletotrichum species were collected from the leaves of the tea-oil tree with anthracnose symptoms from six provinces in China.These isolates were further characterized based on morphology and phylogenetic analysis.All of the isolates were tested for sensitivities to fungicides using the mycelial growth rate method.In total,17Colletotrichum isolates were isolated from diseased leaves of the tea-oil tree.The isolates were characterized as six species,including Colletotrichum camelllae,Colletotrichum fructicola,Colletotrichum siamense,Colletotrichum gloeosporioides,Colletotrichum kahawae,and Colletotrichum horri,and all belonged to Gloeosporioides complex.The isolates were sensitive to prochloraz,with the minimum mean EC_(50)value of 0.035μg/mL,followed by fluazinam,carbendazim,fludioxonil,pyraclostrobin,difenoconazole,epoxiconazole,Benzovindiflupyr and tebuconazole,with the mean EC_(50)values of 0.076,0.169,0.202,0.243,0.342,0.490,0.534 and 1.401μg/mL,separately.In addition,the EC_(50)values of tested isolates to azoxystrobin,boscalid,fluopimomide and fluopyram were higher than 100μg/mL.