Resistance of Eggplant (Solanum melongena L.) to Verticillium Wilt Correlates to Microbial Abundance and Soil Enzyme Activities

Aims: To determine the relationship between microbial abundance and enzyme activities of rhizosphere soil from different resistant eggplant cultivars and resistance of eggplant to Verticillium wilt.
Study Design: The changes of microbial and enzymatic activities of the rhizosphere soil from different resistant eggplants after inoculation of Verticillium dahliae were analysed.
Place and Duration of Study: The plants were grown in a plastic greenhouse of the Vegetable Crops Experimental Station, and the laboratory experiments were conducted at the Horticulture College, Shenyang Agricultural University from August to November, 2008.
Methodology: 14 eggplant cultivars were selected and inoculated with Verticillium dahliae to screen their resistance against Verticillium wilt, and classified according the final disease index. The quantities of main cultivable microorganisms and some functional bacteria were investigated by the serial dilution method. Activities of oxidoreductase and hydrolase enzymes of rhizosphere soil were determined by spectrophotometry or colorimetric titrations.
Results: The correlation analysis among resistance of eggplant to Verticillium wilt, microorganisms and enzyme activities showed that, the abundance of actinomyces, the ratios of bacteria to fungi and actinomyces to fungi, and the activities of catalase, polyphenol oxidase, protease and urease, were significantly positively related with the resistance.