两类木蹄层孔菌在酶蛋白水平上的遗传分化

GENETIC DIFFERENTIATION BETWEEN TWO MORPHOLOGICALTYPES OF FOMES FOMENTARIUS BASED ONISOZYME ANALYSIS

木蹄层孔菌（Ｆｊｏｍｅｓ ｆｏｍｅｎｔａｒｉｕｓ）在中国东北和日本存在子实体形态不同、寄主范围明显有别的两个类型：小型和大型。用多位点分析方法研究了两者间的遗传分化状况。从两类４１个菌株的４种酶系统中检测出９个基因位点，其中８个位点上的绝大多数酶谱型都不为两者所共有，显示两个类型间的基因交流已极少发生。根据酶谱型频率得出两者间的遗传距离Ｄ＝０．９６５，属于典型的种间遗传分化。上述酶基因分化证据结合子实体形态的显著差异，提示两类木蹄层孔菌是各自独立的种。两个类型的群体在遗传多样性参数上无显著差异，可能暗示两者在起源演化上的同步性。酯酶系统有２个位点上的酶谱为不同类型所特有且稳定而清晰，可作为分子标记用于两类木蹄层孔菌的无子实体鉴定。

The wood-decaying fungus Fomes fomentarius has been observed in Japan and Northeastern Chinato have two morphologically different types hased on its fruiting body. Forty-one isolates representing the twotypes collected from China and Japan were subjected to multilocus enzyme analysis, to obtain information aboutthe relationship between the two types. Nine putahve isozyme loci were detected from 4 enzyme systems and on8 of them the two fungal types differed greatly from each other in isozyme phenotype frequencies, indicahng thatlittle gene flow occurs in nature between the two fungal groups. Denetic distance coefficient (D = 0.965) betWeentwo types fell into the magnitude differentiating species. The above isozyme data, in couple with themorphological differences, strongly suggest that the two types are separate species. The level of isozymephenotypic diversity between the two types was not significanUy different possibly suggeshng the synchronism oftheir originahon. The isozyme patterns on two EST loci consistently clishngulshed the two types, demonstratingtheir usefulness for culture identification when fruiting bodies are unavailable.