Chen S N, Luo C X, Hu M J, Schnabel G
College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Department of Agricultural and Environmental Sciences, Clemson University, Clemson, SC 29634.
Plant Dis. 2016 Dec;100(12):2434-2441. doi: 10.1094/PDIS-04-16-0574-RE. Epub 2016 Sep 26.
Few fungicides are effective against anthracnose, caused by Colletotrichum spp., and emerging resistance makes the search for chemical alternatives more relevant. Isolates of the Colletotrichum acutatum species complex were collected from South Carolina and Georgia peach orchards and phylogenetic analysis of the combined internal transcribed spacer region, glyceraldehyde-3-phosphate dehydrogenase, and β-tubulin gene sequences separated the isolates into C. nymphaeae and C. fioriniae. The sensitivity of these and three other previously reported Colletotrichum spp. from peach, including C. fructicola, C. siamense, and C. truncatum, to demethylation inhibitor (DMI) fungicides difenoconazole, propiconazole, tebuconazole, metconazole, flutriafol, and fenbuconazole was determined based upon mycelial growth inhibition. C. truncatum was resistant to tebuconazole, metconazole, flutriafol, and fenbuconazole and C. nymphaeae was resistant to flutriafol and fenbuconazole based on 50% effective concentration (EC) values >100 μg/ml. C. fructicola and C. siamense were sensitive to all DMI fungicides (EC values of 0.2 to 13.1 μg/ml). C. fioriniae subgroup 2 isolates were less sensitive to DMI fungicides (EC values of 0.5 to 16.2 μg/ml) compared with C. fioriniae subgroup 1 (EC values of 0.03 to 2.1 μg/ml). Difenoconazole and propiconazole provided the best control efficacy in vitro to all five species, with EC values of 0.2 to 2.7 μg/ml. Tebuconazole and metconazole were effective against all Colletotrichum spp., except for C. truncatum. The strong in vitro activity of some DMI fungicides against Colletotrichum spp. may be exploited for improved anthracnose disease management of peach.
很少有杀菌剂能有效防治由炭疽菌属（Colletotrichum spp.）引起的炭疽病，而且新出现的抗性使得寻找化学替代品变得更加重要。从南卡罗来纳州和佐治亚州的桃园采集了尖孢炭疽菌复合种（Colletotrichum acutatum species complex）的分离株，并对内部转录间隔区、甘油醛-3-磷酸脱氢酶和β-微管蛋白基因序列进行系统发育分析，将分离株分为睡莲炭疽菌（C. nymphaeae）和佛罗里达炭疽菌（C. fioriniae）。基于菌丝生长抑制测定了这些以及其他三种先前报道的来自桃的炭疽菌属物种，包括胶孢炭疽菌（C. fructicola）、暹罗炭疽菌（C. siamense）和截形炭疽菌（C. truncatum）对脱甲基抑制剂（DMI）杀菌剂苯醚甲环唑、丙环唑、戊唑醇、氟环唑、粉唑醇和腈苯唑的敏感性。基于50%有效浓度（EC）值>100μg/ml，截形炭疽菌对戊唑醇、氟环唑和腈苯唑具有抗性，睡莲炭疽菌对氟环唑和腈苯唑具有抗性。胶孢炭疽菌和暹罗炭疽菌对所有DMI杀菌剂敏感（EC值为0.2至13.1μg/ml）。与佛罗里达炭疽菌亚组1（EC值为0.03至2.1μg/ml）相比，佛罗里达炭疽菌亚组2分离株对DMI杀菌剂的敏感性较低（EC值为0.5至16.2μg/ml）。苯醚甲环唑和丙环唑在体外对所有五个物种提供了最佳防治效果，EC值为0.2至2.7μg/ml。戊唑醇和氟环唑对除截形炭疽菌外的所有炭疽菌属物种有效。一些DMI杀菌剂对炭疽菌属物种的强大体外活性可用于改善桃炭疽病的病害管理。
