【摘要】 收集杨生褐盘二孢菌（Ｍａｒｓｏｎｉｎａｂｒｕｎｎｅａ）两个专化型菌株进行比较研究，发现两专化型菌株在分生孢子形态和大小方面无显著差异，但在培养性状和致病性等方面存在有明显不同。单芽管专化型（Ｍ．ｂｒｕｎｎｅａｆ．ｓｐ．ｍｏｎｏｇｅｒｍｔｕｂｉ）菌落生长速度较快，在ＰＤＡ培养基上产生酱红色孢子堆，人工接种对毛白杨致病性强，对Ⅰ－４５杨、加杨、青杨和小叶杨偶有致病。多芽管专化型（Ｍ．ｂｒｕｎｎｅａｆ．ｓｐ．ｍｕｌｔｉｇｅｒｍｔｕｂｉ）菌落生长速度较前者慢，在ＰＤＡ培养基上产生黄绿色孢子堆，人工接种对Ⅰ－４５杨和加杨致病性强，对毛白杨、青杨和小叶杨致病性较弱。两专化型之内菌株可发生菌丝融合；两专化型之间的菌株菌丝不能融合。更多还原

【Abstract】 Comparing the isolates which three belong to Marssonina brunnea f.sp. monogermtubi and four belong to Marssonina brunnea f.sp. multigermtubi ,no significant difference was found on the morphological features of conidia (shape,mean dimension,size and septum location).But there are much difference occourring on the cultural features and pathogenicity between the two specialized forms.The isolates of M.brunnea f.sp. monogermitubi possesses the characteristics of faster colony growth, dark reddish conidiosorus production on PDA medium, mostly pathogenic to P.tomentosa and slightly pathogenic to P.×euramericana Ⅰ 45, P.canadensis , P.cathayana and P.simonii by artificialinoculation.The isolates of M.brunnea f.sp. multigermtubi , however,has the characteristics of slowly colony radial growth and yellowish green conidiosorus production, seriously pathgenic to P.×euramericana Ⅰ 45 and P.canadensis , also pathgenic to P.tomentosa, P.cathayana and P.simonii .The test of hyphal anastomoses showed that the hyphae which of the same specialized form can anastomose together.Hyphal anastomoses shall not occour between two hyphae which come from two different specialized forms.更多还原