不同属宿主来源的Frankia菌株形态特征的研究

STUDIES ON MORPHOLOGICAL CHARACTERISTICS OF FRANKIA STRANIS FROM DIFFERENT HOST PLANTS

利用光学显微镜和扫描电镜系统研究了从赤扬、香蕨木、扬梅、木麻黄、异木麻黄、沙棘、胡颓子等七个属中13个树种根瘤中分离出来的15株Frankia菌株。发现不同属、种来源的Frankia菌株除具有相似的形态特征外,在菌丝的粗细、菌丝体发育的稀疏、微密程度、孢子囊的大小,顶囊的形状、大小和顶囊柄的长短等均有着明显的差别。不同属来源的Frankia菌株在培养特征上有明显的差异。赤扬属不同种来源的Frankia菌株在以丙酸钠为碳源的Bap液体无氮培养基中均生长良好,但在以丙酮酸钠为碳源时,则不能生长,而木麻黄属、异木麻黄属来源的Frankia菌株,在丙酸钠或丙酮酸钠为碳源时均生长良好。沙棘属、胡颓子属来源的Frankia菌株在丙酸钠或丙酮酸钠为碳源时均生长良好并产生棕褐色色素。根据Frankia菌的形态和培养特征,可将七个属来源的Frankia菌株划分为三个类群:即赤扬香蕨木,扬梅类群;木麻黄、异木麻黄类群;沙棘和胡颓子类群。

Frankia strains from Alnus, Comptonia, Wyrica, Casuarina, Allocasuarina, Hippophae and Elaeagnus were studied by optical microscopy and scanning elctron microscopy. Results show that Frankia strains from different hosts have their own morphological characteristics in width of hyphae, loose or close arrangement of mycelium, size of sporongium, size and form of vesicle, length of vesiclephore. Frankia strains from Alnus only use Na-propionate as C-source in Bap medium, can not grow in Na-pyruvate medium. Frankia strains from Casuarina and Allocasuarina can use Na-propionate and Na-pyruvateeas C-source Frankia strains from Hippophae and Elaeagnus use Na-propionate and Napyruvate as C-source and produce brown pigment in both media. According to their morphological and cultural characteristics Frankia strains from above 7 genuera hosts can be classified into three groups. Ⅰ. group contains Frankia strains from Alnus, Comptonia and Myrica. Ⅱ. group contains Frankia strains from Casuarina and Allocasuarina. Ⅲ. group contains Frankia strains from Hippophae and Elaeagnus.