香蕉枯萎病菌对土壤线虫群落组成及多样性的影响

Effects of banana wilt disease on soil nematode community structure and diversity

为了探明香蕉枯萎病病原菌对土壤生态系统健康水平的影响,利用土壤线虫作为指示生物,对比研究了海南香蕉枯萎病发病蕉园和未发病蕉园土壤线虫营养类群及生态指数之间的差异.结果表明:发病区和对照区共鉴定出土壤线虫属31个,发病区26个,对照区28个;发病区土壤线虫总数、10～30cm土层食细菌线虫数量、植物寄生线虫数量显著低于对照区(P<0.01),10～20cm土层食真菌线虫数量显著高于对照区(P<0.01);随着土层深度增加,发病区土壤线虫总数、食细菌线虫数量逐渐降低(P<0.01),植物寄生线虫数量逐渐增加(P<0.05),对照区土壤线虫总数、植物寄生线虫数量逐渐降低(P<0.05);发病区香农多样性指数(H′)、成熟度指数(MI)、结构指数(SI)和富集指数(EI)均显著低于对照区(P<0.01),优势度指数(λ)显著高于对照区(P<0.01);随着土层深度增加,发病区和对照区(10～20cm土层)的结构指数(SI)逐渐增加(P<0.01).说明香蕉枯萎病病原菌改变了土壤线虫的群落结构,降低了土壤线虫群落的多样性.

To investigate the effect of pathogen causing banana wilt disease on soil ecosystem health,the differences of soil nematode trophic groups and ecological indices between banana wilt disease soil and control soil were compared in Hainan Province using soil nematode as bioindicator.The results showed that 31 nematode genera in the disease area and control area were identified,26 of which was in disease area,28 in control area.The abundance of total nematodes,bacterivore in 10-30 cm soil layer and plant parasites and the values of Shannon-Wiener diversity index（H′）,maturity index（MI）,structure index（SI） and enrichment index（EI） were significantly lower（P 0.01） in the disease area than in the control area,while those of fungivores and Simpson＇s dominance index（λ） exhibited quite a reverse condition.The abundance of total nematodes and bacterivore decreased（P 0.01） while those of plant parasites and the values of SI increased（P 0.01） with increasing soil depth in the disease area.The abundance of total nematodes and plant parasites decreased （P 0.05） and the values of SI（P 0.01） increased with increasing soil depth in the control area.It is indicated that pathogen causing banana wilt disease changed soil nematode community structure and decreased diversity of soil nematode community.