Fruit blotch of watermelon [Citrullus lanatus (Thumb)] in Northeastern Thailand: etiology and factors affecting disease development
1996
Pinyapong, P.S. | Natural, M.P. (Philippines Univ. Los Banos, College, Laguna (Philippines))
Thirty strains of the fruit blotch bacterium were isolated from three watermelon areas in Northeastern Thailand. All isolates were Gram-negative, non-spore forming rods, about 0.9 x 1.8 m, having a single polar flagellum. The colonies were convex, circular and entire. No flourescent pigment was produced in KB medium. Other morphological, physiological and biochemical properties suggest that the causal bacterium was Acidovorax avenae subsp. citrulli (syn. Pseudomonas pseudoalcaligenes subsp. citrulli Schaad and others, 1978). Seed transmission was not observed from the limited number of seeds collected from naturally infected plants. However, watermelon seedlings of 10 hybrids with seeds soaked in bacterial suspension before planting developed symptoms one week after. Disease incidence was 0.83 percent. Factors that affected development of fruit blotch in watermelon fruits were inoculum concentrations, age of fruits, wounds and variety
显示更多 [+] 显示较少 [-]