嫁接对茄子根际土壤微生物种群的化感效应

研究了嫁接茄根际微生物种类的动态变化及对抗病性的影响，并对嫁接茄根际拮抗菌进行了筛选。土壤稀释分离法进行根际微生物分离，结果表明：总体上，嫁接增加了根际微生物总量、细菌（B）、放线菌数量（A），减少了真菌数量（F），增加了B/F和A/F比值，降低了黄萎菌病情指数及发病率，延缓了发病时间。从嫁接和自根茄根际共分离得到的 352个菌株，通过平皿对峙法、孢子萌发法及牛津杯法筛选出7株对茄子黄萎病菌具有拮抗作用的菌株。通过盆栽防病试验测定了这7株拮抗菌对茄子黄萎病的防治效果，筛选出有明显拮抗作用的细菌菌株X631和真菌菌株Z111。初步鉴定X631和Z111分别属于沙雷氏菌属和木霉菌属。本试验结果说明嫁接改变了茄子根际微生物种群数量和结构，增加了有益菌数量，进而增强了茄子的抗病性。

Allelopathic Effects of Grafting on Rhizosphere Microorganisms Population of Eggplants

The changes of microbial community structure in rhizosphere soil of grafted eggplants at different stages and the effect of grafting on resistance of eggplant were studied. Antagonistic microbes from rhizosphere of grafted eggplants were screened. Microorganism from rhizosphere of eggplants was isolated by soil dilution. Compared with self-root eggplant, grafting changed microbial community structure in rhizosphere of eggplants, with increase of bacteria (B) and actinomyces (A), decrease of fungi (F), enhancement of the ratios of B to F and A to F, and also decrease of disease incidence of Verticillium wilt. Through ordinal determination of a dual culture, the spore germination and a cylinder-plate, 7 strains from 352 strains isolated from rhizosphere of grafted eggplant indicated significant inhibitory effect against Verticillium dahiae. In pot trial, two antagonistic strains of X631 and Z111 showed significantly inhibitory effect against Verticillium dahiae. Through preliminary identification, strain X631 is Serratia Bizio, and strain Z111 is Trichoderma. The results from this study indicated that the rhizosphere microbial community via grafting is favorable to eggplant's resistance and growth.