苜蓿来源的变黑轮枝菌及其致病性

Verticillium nigrescens from Alfalfa and Its Pathogenicity

苜蓿(Medicago sativa L.)是重要的牧草和控治水土流失的重要植被。近年来,苜蓿病害日趋严重,成为苜蓿种植的限制因素。采用常规组织分离法和柯赫氏证病律,从发白矮化的苜蓿病株中分离得到一种病原菌,结合形态学和ITS序列分析,鉴定为变黑轮枝菌(Verticillium nigrescens Pethyhr.),可引起苜蓿叶片发白,节间缩短,植株矮化等症状,但发病植株维管束不变色,不形成黑白轮枝菌引起的典型"V"字型病斑。该病菌对苜蓿和茄子有一定致病性。

Alfalfa（Medicago sativa L.） is an important grass and vegetation to control soil erosion.Alfalfa diseases become a limit factor in alfalfa production in recent years.One pathogen was isolated from white and dwarf alfalfa using tissue isolating method and Koch＇s rules.The strain was identified as Verticillium nigrescens based on morphology and internal transcribed spacer（ITS） sequence.It can cause discoloration,internode shortening,and dwarf of alfalfa.However,the vascular of diseased alfalfa did not show discoloration.No typical ＂V＂ symptom which caused by Verticillium albo-atrum appeared on the leaf of diseased alfalfa.The pathogen has a certain pathogenicity to alfalfa and eggplant.