铁皮石斛根腐病原尖孢镰刀菌生物学特性及其有效杀菌剂筛选

Biological Characteristics and Fungicides Screening of Fusarium oxysporum on Root Rot in Dendrobium officinale

根腐病是铁皮石斛种植生产中的一种严重病害,本研究测定铁皮石斛根腐病原菌生物学特性和室内药剂筛选,预期为该病害的田间防治提供数据。结果发现铁皮石斛根腐病原Fusarium oxysporum菌丝生长、产孢和孢子萌发最适温度为25℃;孢子萌发相对湿度要求高于75%,湿度越大,萌发率越高;菌丝生长、产孢最适pH为7;菌丝生长最适碳氮源分别是果糖和硝酸钠;光照条件对菌丝生长和孢子萌发无明显影响;病原菌分生孢子致死温度为55℃、10 min;9种供试杀菌剂对尖孢镰刀菌的毒力从大到小为:精甲·咯菌腈>腈菌唑>噻菌铜>丙环唑>噁菌灵>戊唑醇>三唑酮>氟硅唑>代森锰锌。精甲·咯菌腈、腈菌唑和丙环唑对铁皮石斛根腐病原尖孢镰刀菌抑菌活较高,可作为该病害的田间防治参考。

Root rot is a serious disease in Dendrobium officinale planting.In order to provide data for control on root rot of Dendrobium officinale in field,the biological characteristics and effective fungicides screening of Fusarium oxysporum were determined indoors.The results showed that the optimal temperature for mycelial growth,sporulation and spore germination of Fusarium oxysporum was 25℃.Most of spores could germinate when the relative humidity was over 75%.The optimal pH of mycelial growth and sporulation was 7,the optimum carbon and nitrogen sources for mycelial growth were respectively fructose and sodium nitrate.The illumination conditions had no significant effect on mycelial growth and spore germination;the lethal temperature of conidia was 55℃ for 10 min.Indoor toxicity tests of nine fungicides demonstrated that the bioactivity against Fusarium oxysporum were:metalaxy-m mixed fludioxonil>myclobutanil>thiodiazole-copper>propiconazole>hymexazol>tebuconazole>triadimefon>flusilazole>mancozeb.And the metalaxy-m mixed fludioxonil,myclobutanil and propiconazole were most effective to Fusarium oxysporum,which would be used as a reference for field control of this disease.