关键词: 灰金合欢根瘤, 类菌体细胞分裂, 宿主细胞器, 超微结构

Abstract: The early period of symbiotic growth in the Acacia glauca nodule cells is characterized by an increase in the number of rhizobia-bac-teroid and host cytoplasm and organelles. The bacteroids increase by fission until they occupy most region of host cytoplasm. Surrounding bac-teroid membrane envelopes contain one or more bacteroids. The late period of symbiotic growth involves changes in the structure of bacteroid cells as well as the number of host cell organsllos. The symbiotic nitrogen fixation of the nodules is also discussed.

Key words: Acacia glauca nodules, Bacteroid cell fission, Host organel-les, Ultrastructure