ULTRASTRUCTURAL STUDY ON THE FUSION AND SENESCENT DISINTEGRATION OF PERIBACTEROID MEMBRANE IN ACACIA ROOT NODULES Freeze fracture study on peribacteroid membranes in soybean root nodules ADVANCES OF STUDIES ON BACTEROID REPRODUCTION OF R.trifolii,Rhizobium leguminosarum, AND FAST-GROWING SOYBEAN RHIZOBIUM Effects of essential oil from Cinnamomum Cassia on Clostridia flora IV and Bacteroides in gut of rats Role of Endoplasmic Reticulum in the Formation of Peribacteroid Membranes Electron Microscopic Observation on the Infected Cells During Pea (Pisum sativum L.) Nodule Senescence THE ULTRASTRUCTURE OF ROOT NODULE CELLS OF LEUCAENA LEUCOCEPHALA Origin and role of the vesicles located near the plasma membranes of infected cells Diversity of Origin and Expansion Mode of Peribacteroid Membrane in Legume Nodules