Diversity of Phosphate-Dissolving Microorganisms in Corn Rhizosphere

<正> Rhizosphere and nonrhizopshere soils were sampled during corn growth. Total, inorganic phosphate-dissolving and lecithin-mineralizing bacteria, fungi and actinomyctes were determined by plate counting method. Generally, the rhizosphere soil contained around 5 to 100 times more of these bacteria and fungi than the non-rhizosphere soil. However, the actinomycetes in the rhizosphere soil were significantly lower than those in the non-rhizosphere soil. The numbers of these microorganisms didn’t significantly change during corn growth in the soils. However, the proportion of the phosphate-dissolving microorganisms in the total changed markedly during corn growth. Generally there were much higher percentages of phosphate-dissolving bacteria and phosphate-dissolving fungi in the rhizosphere soil than the nonrhizosphere soil. More than 90% of the fungi in rhizosphere dissolved inorganic phosphate at the seedling period, but this proportion declined to 20% at the harvesting time. The community of phosphate-disso