人参生炭疽菌(Colletotrichum panacicola)和线列炭疽菌(C. lineola)的生物学特性及其对不同杀菌剂的敏感性研究

 近年来,炭疽属真菌(Colletotrichum spp.)引起的人参炭疽病,给人参生产造成了重大经济损失。本文选取分离自我国吉林省栽培人参上的两种炭疽菌人参生炭疽菌(Colletotrichum panacicola)和线列炭疽菌(C. lineola),通过平板培养,测定了它们在不同培养基、温度、碳源、氮源、pH值和光照条件下的生物学特性;采用菌丝生长速率法测定了其对14种杀菌剂的敏感性。结果表明,两种炭疽菌的最适生长温度均为25 ℃,最适生长pH值均为7,光暗交替有利于两种菌的菌丝生长。其中,人参生炭疽菌的菌丝生长最适培养基为V8汁培养基,最适碳源和氮源分别是淀粉和硝酸钾;线列炭疽菌的菌丝生长最适培养基为PDA和PSA培养基,最适碳源和氮源分别是淀粉和硝酸铵;两种炭疽菌对13种药剂敏感,咯菌睛、戊唑醇、抑霉唑、多菌灵、氟环唑、苯醚甲环唑、己唑醇、甲基硫菌灵8种药剂对两种炭疽菌的室内抑菌活性较好,EC₅₀值均小于5.0 μg·mL^-1。咯菌睛、戊唑醇、抑霉唑、多菌灵、氟环唑、苯醚甲环唑、己唑醇、甲基硫菌灵8种药剂对两种炭疽菌的室内抑菌活性较好,EC₅₀值均小于5.0 μg·mL^-1,其中咯菌睛抑菌活性最强,EC₅₀值均小于0.1 μg·mL^-1。两种炭疽菌对同一药剂的敏感性存在差异,线列炭疽菌对吡唑醚菌酯敏感性较高,EC₅₀值小于0.1 μg·mL^-1,而人参生炭疽菌对该药剂的敏感性相对较低(EC₅₀值高于200 μg·mL^-1)。该结果为人参炭疽病发病规律的研究及其田间有效防治奠定了基础。

Biological characteristics and fungicide sensitivity of Colletotrichum panacicola and C. lineola causing anthracnose on ginseng

In recent years, anthracnoses caused by Colletotrichum spp. on ginseng has occurred heavily, which are responsible for important economic loss on the production of ginseng. In this study, two species, C. panacicola and C. lineola isolated from diseased ginseng in Jilin province, were selected to study their biological characteristics and fungicide sensitivities. Mycelial growth of each species was measured under different media, temperatures, carbon and nitrogen sources, pH values, and light conditions by plate cultures, respectively. The sensitivity of the tested strains to 14 fungicides was determined based on mycelial growth inhibition method. The results of characteristics for the two species showed that the optimal temperature and pH for mycelial growth for both species were 25 ℃ and 7, respectively, and alternating light and dark was more suitable for mycelial growth of the two species. The optimal medium for mycelial growth of C. panacicola was V8 juice medium, while PDA and PSA media were more suitable for C. lineola. The optimal carbon and nitrogen sources for mycelial growth of C. panacicola were starch and potassium nitrate and those were starch and ammonium nitrate for C. lineola. Both C. panacicola and C. lineola were sensitive to 13 out of 14 tested fungicides, among which eight fungicides such as fludioxonil, tebuconazole, imazalil, carbendazim, epoxiconazole, difenoconazole, hexaconazole and thiophanate-methyl had better inhibition effect against the two species than other fungicides with the EC₅₀ values less than 5.0 μg·mL^-1. Fludioxonil was the most sensitive tested fungicides for the two species with the EC₅₀ va-lues less than 0.1 μg·mL^-1. Howerer, there were some differences of the two species to the same fungicide, C. lineola was more sensitive to pyraclostrobin, and the EC₅₀ value was less than 0.1 μg·mL^-1, while the EC₅₀ value of C. panacicola to this fungicide was more than 200 μg·mL^-1. This study clarified the biological characteristics of C. panacicola and C. lineola on ginseng and the fungicide sensitivities were also studied in vitro, which provided the foundation for the further studies on the occurrence rules and effective control for the ginseng anthracnose disease.