菠萝及玉米轮作对连作蕉园土壤微生物区系及发病率的影响

In this study, effects of pineapple-banana and maize-banana systems on the next season banana fusarium wilt disease were investigated, and cultural dependent plate-counting and PCR-DGGE methods were used to investigate the microbe community structure influenced by pineapple and maize rotations. Results showed that lower fusarium wilt diseases were observed in pineapple rotation sites; Fusarium populations in the banana rhizosphere soil samples from pineapple rotation sites were significantly lower than that from the maize rotation and banana continuous sites; and the percentage of antagonistic Pseudomonas isolated from pineapple-banana rotation sites was significantly higher. The root and plant extracts from pineapple had significantly inhibition action on mycelia growth and conidium germination of Fusarium oxysporum f.sp. cubense (Foc)，showing concentration effects on Foc. Results from comparation on the soil samples in season showed that Foc number in pineapple rhizosphere soil significantly lower than that in banana and maize soils. Based on fungi PCR-DGGE fingerprints, the bands related to Fusarium sp. from pineapple-banana treatment soil was obviously weakened than maize-banana and banana continuous treatment and the cluster and composition of the soil fungal community were totally altered. In conclusion, all the results indicated that pineapple rotated with banana could effectively improve soil microflora and control the banana Fusarium wilt disease.