Abstract
Growth patterns of Xanthomonas citri and Erwinia herbicola were compared in mixed cultures as well as individual cultures in peptone-sucrose broth, intercellular fluid of citrus leaves and intact leaf tissues. At 30C, E. herbicola grew rapidly inhibiting growth of X. citri regardless of concentration of nutrients in peptone-sucrose broth. At 20C, however, both bacteria continued to grow for 24hr. In intercellular fluid sampled in July, E. herbicola was selectively depressed in contrast to the continuous growth of X. citri. This effect was not observed in the intercellular fluids sampled in October and February. When X. citri was injected into mesophyll of citrus leaves, nutrient substances were released from host cells into intercellular spaces 6 to 9hr after inoculation. In mixed inoculation, growth of E. herbicola occurred only when the population of X. citri reached 107CFU/cm2.
