紫穗槐根瘤菌的分离与回接鉴定

Isolation and Back Inoculation Characterization of Rhizobia from Shrubby Falseindigo(Amorpha fruticosa)

采用YMA培养基对新鲜的紫穗槐（AmorphafruticosaL．）根瘤提取物进行根瘤菌的分离培养，获得的菌落为圆形乳白色，表面凸起，直径0．4—0．5cm，革兰反应阴性，显微观察显示为短杆状，分离菌株回接原宿主植物，同时接种于经60℃15min水浴加热处理的紫穗槐种子，蛭石盆栽实验显示，接种此菌的紫穗槐植株都有结瘤，并与对照在结瘤数、瘤重、植株鲜重与干重间都有显著差异，实验证明所分离的菌株均为紫穗槐根瘤菌。

Extract of Amorpha fruticosa （Af） fresh nodules were isolated and cultivated on YMA medium to carry out rhizobia isolation. The isolated organisms were Gram-negative short rod. The obtained colonies on the medium was round and creamy-white having raised surface, 0.4 ~ 0.5 cm in diameter. The isolated strains were inoculated back onto the host plant and Af seeds that was treated in 60℃ water bath for 15 min. The results of experiment in vermiculite flowerpot showed that the isolated strains were rhizobia of Af. All plants that had inoculated were nodulated. There were obvious differences in quantity and weight of nodule, fresh and dried between treatment and control; the experiments had proved that the isolated strains were rhizobia of Af.