School of Life Sciences, Henan University, Kaifeng, 475004, China.
College of Environment and Planning, Henan University, Kaifeng, 475004, China.
Sci Rep. 2019 Aug 12;9(1):11660. doi: 10.1038/s41598-019-48230-0.
Both earthworms and plants may affect the soil nematode community. However, the effects of earthworms and plant species interactions on soil nematode community are poorly understood. We explored how an epigeic earthworm Eisenia fetida affects the soil nematode community in systems with three representative plants (wheat, cotton and cabbage) which were grown in pots with or without added earthworms under greenhouse conditions. Earthworm presence decreased the abundance of total nematode and all four nematode trophic groups, except for the fungivore and predator/omnivore nematodes in wheat systems, but increased the genus richness of nematode in all treatments. Due to plant identity and different root exudates, plants had significant effects on soil nematode abundance. Compared with the no plant and without earthworm treatment, wheat and cabbage had the higher stimulation of the abundance of total nematode, bacterivores and fungivores, and cotton had the higher stimulation of the abundance of fungivores and predators-omnivores; whereas earthworm presence mostly weakened the stimulation effects of plant species on soil nematode abundance which indicated earthworms had the enhanced effects in the presence of plants. The interaction affected soil nematode abundance (total nematodes, bacterivore, fungivore and omnivore-predators) and community diversity indices (diversity index H', evenness index J', community maturity index ∑MI, Simpson dominance index λ and nematode channel ratio NCR). Principal component analysis showed that plant species affected soil nematode community composition. Redundancy analysis indicated plant species and biomass accounted for 41.60% and 34.13% of the variation in soil nematode community structure, respectively; while earthworms explained only 6.13%. Overall, current study suggest that earthworm could inhibit nematode abundance; whereas, plants have exerted greater influences on nematode community structure than earthworm presence due to their species-specific effects on different trophic groups of nematodes.
蚯蚓和植物都可能影响土壤线虫群落。然而，蚯蚓和植物种间相互作用对土壤线虫群落的影响知之甚少。我们在温室条件下，通过在有或没有添加蚯蚓的盆中种植三种代表性植物（小麦、棉花和白菜），来探索表栖蚯蚓赤子爱胜蚓（Eisenia fetida）如何影响土壤线虫群落。蚯蚓的存在降低了总线虫和所有四个线虫营养类群的丰度，除了小麦系统中的食真菌线虫和捕食者/杂食性线虫外，但增加了所有处理中的线虫属丰富度。由于植物的身份和不同的根分泌物，植物对线虫丰度有显著影响。与无植物和无蚯蚓处理相比，小麦和白菜对线虫总丰度、细菌食性线虫和真菌食性线虫的丰度刺激作用较高，而棉花对线虫中真菌食性线虫和捕食者-杂食性线虫的丰度刺激作用较高；而蚯蚓的存在大多削弱了植物对线虫丰度的刺激作用，这表明蚯蚓在植物存在的情况下具有增强作用。互作影响土壤线虫丰度（总线虫、细菌食性线虫、真菌食性线虫和捕食者-杂食性线虫）和群落多样性指数（多样性指数 H'、均匀度指数 J'、群落成熟度指数∑MI、辛普森优势度指数 λ和线虫通道比 NCR）。主成分分析表明，植物种类影响土壤线虫群落组成。冗余分析表明，植物种类和生物量分别解释了土壤线虫群落结构变化的 41.60%和 34.13%；而蚯蚓仅解释了 6.13%。总体而言，本研究表明蚯蚓可能抑制线虫丰度；然而，由于植物对线虫不同营养类群的特定影响，它们对线虫群落结构的影响大于蚯蚓的存在。
