Scanning electron microscopic observation of bacteria in pea root nodules.

The infected cells in pea(Pisum sativum L.) root nodules were observed by scanning electron microscopy.Results showed that in the infected cells there were a large quantity of bacteria which were very different in shape.They were mainly rod-shaped bacteria,secondly,were spherical bacteria,often Y-shaped bacteria and T-shaped bacteria were also seen,but other shaped bacteria were a little.Besides the bacterial shape was not completely same,there still were some bacteria which were very special in these cells.Such as some bacteria were longer,often occurred contraction in one or some parts and formed one or more than one contractile rings,so its shape was like a lotus root;Some bacteria were specially large in size,it was 2 or more than 2 times of a general bacterium;two ends of some bacteria were not same thick and one end often swelled,its shape was similar to a wooden club.In these infected cells there were many vesicles which were different in size,but they all were sphere.They were located among bacteria,even some vesicles appeared on the surfaces of the bacteria,and there were many bacteria near them,sometimes the surfaces of these bacteria possessed various bulgings.