烟叶米根霉检测、碳源代谢表型及其对7种杀菌剂的敏感性

采用组织分离法检测了烘烤烟叶霉烂病病原菌米根霉Rhizopus oryzae，采用Biolog FF代谢板分析了其碳源代谢表型特征，并测定了其对7种杀菌剂 (多菌灵、异菌脲、咪鲜胺、氟硅唑、丙环唑、苯醚甲环唑和嘧菌酯) 的敏感性。结果表明:米根霉在田间烟叶、编烟杆和编烟绳上的检出率均为100%。米根霉能代谢和产孢的碳源分别有66和30种，主要包括核糖醇、D-阿拉伯醇和?-环式糊精等；不能代谢和产孢的碳源分别有29和65种，包括α-环式糊精、L-海藻糖和D-半乳糖醛酸等。7种杀菌剂对烟草米根霉的菌丝生长均表现出不同的抑制作用，抑菌活性最强的是氟硅唑和苯醚甲环唑，其EC₅₀值分别为8.31和9.71 mg/L；其次为丙环唑、异菌脲和咪鲜胺，其EC₅₀值分别为14.24、32.84及 > 10 mg/L；最弱的为嘧菌酯和多菌灵，其EC₅₀值均 > 100 mg/L。研究结果可为烘烤烟叶霉烂病化学防治提供参考和依据。

Pathogen detection, carbon metabolic phenotype analysis of Rhizopus oryzae from tobacco and its sensitivity to seven fungicides

Pathogen detection of Rhizopus oryzae, which causes tobacco pole rot, was conducted using tissue isolation method. The carbon metabolic phenotype of the pathogen was studied with Biolog FF microplate. The sensitivity of R. oryzae to seven different fungicides (carbendazim, iprodione, prochloraz, flusilazole, propiconazole, difenoconazole and azoxystrobin) was also evaluated. Results showed that the detection ratios of R. oryzae from samples of tobacco leaves, tobacco baking stick and tobacco baking rope were all 100%. The numbers of carbon for metabolization and sporulation of R. oryzae were 66 and 30, respectively, which included ribitol, D-arabitol, ?-cyclodextrin, etc. While for no-metabolization and no-sporulation carbons, the numbers were 29 and 65, respectively, which included α-cyclodextrin, L-trehalose, D-galacturonic acid, etc. All the seven fungicides showed different inhibitory activities against the mycelial growth of R. oryzae. Highest sensitivities were detected when flusilazole and difenoconazole were applied, with EC₅₀ values of 8.31and 9.71 mg/L, respectively. And EC₅₀ values of propiconazole, iprodione and prochloraz were 14.24, 32.84 and > 10 mg/L, respectively. While carbendazim and azoxystrobin have the lowest activities with the EC₅₀ values > 100 mg/L. Results of this study provided reference and basis for the chemical control of tobacco pole rot.