STUDIES ON LIFE CYCLE AND MORPHOLOGY OF POLYMYXA BETAE
甜菜多粘菌形态发育过程研究

Polymyxa betae, vector of beet necrotic yellow vein virus, is an obligate parasite and it has a very close relation to "rhizomania" disease of sugar beet. The penetration process of P. betae into beet root was studies in detail. Every main developing stage of P. betae in its life cycle was observed both under light and electron microscope. Some BNYVV-like particles were found in zoospore of P. betae. On the basis of these studies, we put forward a diagrammatic representation of life cycle of Polymyxa betae.