Effects of grafting on rhizosphere microorganisms of eggplants

We studied the changes in rhizosphere microbial community of grafted eggplants at different stages and the effect of grafting on disease resistance of eggplant. Antagonistic microbes against Verticillium dahiae from rhizosphere soil of grafted and non-grafted eggplants were screened. Compared with non-grafted eggplant, grafting changed the rhizosphere microbial community structure of eggplants, the increase of bacteria (B) and actinomycetes (A), decreased the fungi (F), increased ratios of B to F and A to F, also decreased incidence of Verticillium wilt. Of the 352 strains isolated from rhizosphere soil of grafted and non-grafted eggplants, 7 strains were inhibitory against Verticillium dahliae and their inhibition zone was > 13 mm. In greenhouse experiment, two antagonistic strains ‘B631’ and ‘F111’ showed significant inhibitory effects against Verticillium dahliae. The prevention and curative effects of strain ‘B631’ and strain ‘F111’ on Verticillium wilt were 62.50%, 53.33%, 56.25% and 46.67%, respectively. Using the taxonomic classification and Bergey's Manual of Determinative bacteriology, ‘B631’ was identified as Serratia Bizio and ‘F111’ was identified as Trichoderma. The results from this study indicated that the rhizosphere microbial community from grafting is favourable to eggplant's disease resistance.