Pathogen Identification Of Two New Occurring Bacterial Diseases On Vegetables

Bacterial disease of vegetables, which made serious damage, with fungous disease and virus disease were known as the three prevalent vegatable diseases. Due to the diversity of the cultivars and cultural manners, bacterial disease of vegetables had been increasing in recent years, causing enormous economic losses. In this paper, we made a preliminary study on the domestic common bacterial diseases of vegetables, and identified two new occurring diseases, found new symptoms of a traditional disease, deeply studied and identified three serious infecting diseases.(1) A preliminary study on the domestic common bacterial diseases of vegetables was made. More than 200 copies of infected samples had been collected from all over the country. By means of microscopic examination of bacteria overflow, inspecting the diseased symptoms and the colony morphology of isolated strains, a preliminary identification of the diseases was conducted. Simultaneously, 310 suspected strains were preserved.(2) Two new occurring diseases were identified by biochemistry and molecular biology technology. One was coriander bacterial leaf spot caused by Pseudomonas syringae pv. coriandricola, which was a new record species of host in China. The other was Physalis bacterial leaf spot caused by a Enterobacter sp., which was a new record species of host all over the wold.(3) New symptoms of traditional disease ware found through repeated pathogenicity tests and the technology of molecular biology. The marginal necrosis of tomato leaf was apparent, most of the plants dried up and collapsed. And the traditional symptoms with canker and bird's spot were not even shown.(4) The pathogens of three serious diseases were identified by the technology of biochemistry and molecular biology. The three pathogens, Acidovorax avenae subsp. citrulli Willems et al., Erwinia carotovara subsp. carotovara (Jones) Bergey et al. and Xanthomonas campestris pv. campestris (Pammel) Dowson. were identified. They caused melon bacterial fruit blotch, cabbage black rot and pepper bacterial scab respectively.By the means of traditional methods and the technology of biochemistry, molecular biology, a compositive study to identify the pathogens of traditional and new occurring bacterial diseases in China was made, which was theoretically and practically significant to correctly recognize the bacterial diseases of vegetables and scientific prevention and treatment to reduce economic loss in agricultural production.