韭菜根系浸提液对香蕉枯萎病和土壤微生物生态的影响

通过抑菌试验(采用菌丝生长速率法和孢子萌发法)和盆栽试验,研究了韭菜根系浸提液对香蕉枯萎病的抑菌效应和防治效果,以及对土壤微生物生态的影响.抑菌试验结果表明,韭菜根系浸提液对香蕉枯萎病菌菌丝生长和孢子萌发均具有明显的抑制作用,并表现出浓度效应,即随着韭菜根系浸提液质量浓度的增加,菌丝生长减缓,孢子萌发率降低,对病原菌菌丝生长和孢子萌发的抑制作用增强.通过对病原菌菌丝和孢子形态的显微观察,韭菜根系浸提液能使病原菌菌丝和孢子发生畸变.香蕉苗期接种试验防病效果显著,随着韭菜根系浸提液质量浓度的增加,防病效果增强,当达到最大测试质量浓度160 mg·mL-1时,防病效果达到53.66%.韭菜根系浸提液影响盆栽土壤中香蕉枯萎病菌和主要微生物类群数量:韭菜根系浸提液能显著减少土壤中香蕉枯萎病菌、真菌和放线菌数量,提高细菌的数量.移栽香蕉后第40天的Biolog分析结果表明:韭菜根系浸提液能够提高土壤微生物对碳源的利用能力和土壤微生物群落的多样性、丰富度和均匀度,说明韭菜根系浸提液能改善土壤微生物群落结构,增强土壤微生物生态系统的稳定性和抑病性,从而减少香蕉枯萎病病害的发生.

Effects of Allium tuberosum Root Extracts on Banana Fusarium Wilt and Soil Microbial Ecology

The inhibition effects and the disease-control efficiency of Allium tuberosum root extracts on Foc4(Fusarium oxysopoyum f.sp.cubence race 4), and root extracts effects on soil microbial ecology were studied by bacteriostatic experiment (mycelia growth rate method, spore germination method and pot trial). The results of bacteriostatic test indicated that A. tuberosum root extracts had significantly inhibition action on mycelia growth and conidium germination of Foc4, showing concentration effects on Foc4. In addition, the aberration of the morphology of mycelia and conidium of Foc4, which were impacted by A. tuberosum root extracts, was found by microscopic observation. The results of pot trial showed that the occurrence of banana fusarium wilt decreased significantly by A. tuberosum root extracts, and disease-control efficiency increased with the increase of root extracts concentration. When the root extracts concentration reached 160 mg·mL^-1, the disease-control efficiency was up to 53.66%. A. tuberosum root extracts could affect the numbers of Foc4 and the main microorgnanisms in the soil, which was presented as the numbers of Foc4, fungi and actinomyces in the soil were reduced, while the numbers of bacteria in the soil increased evidently. The Biolog analyses on the 40th planting days showed that A. tuberosum root extracts could noticeably increase carbon source utility by microbes and soil microbial community diversity, richness, uniformity, which manifested that A. tuberosum root extracts could adjust soil microbial community structure, enhance soil microbial ecological system stability and inhibition of disease, thus reducing the occurence of soil born disease.