高通量测序分析冻融期碳源输入方式对土壤线虫群落的影响

植物碳源输入途径变化对土壤生物群落的影响研究是目前学术界关注的热点问题。为探究温带森林生态系统碳源输入方式对土壤线虫群落的影响,通过Illumina MiSeq技术分析了不同碳源输入方式下土壤线虫群落组成和多样性的变化。研究结果显示:所有处理(凋落物和根系同时输入;仅根系输入;仅凋落物输入;无碳源输入)中共发现土壤线虫68属,其中食细菌线虫的相对丰度最大;各碳源输入方式中仅凋落物输入处理对线虫群落组成的影响最为明显,表现为:与凋落物和根系同时输入处理相比,仅凋落物输入处理中食细菌线虫的相对丰度明显增加,食真菌线虫的相对丰度显著降低以及捕食杂食线虫的相对丰度显著增加。从线虫群落的多样性指数角度看,无碳源输入处理中土壤线虫群落的多样性指数(H'')下降,优势度指数(Dom)增高;仅凋落物输入处理中均匀度指数(J)最高。从线虫群落的生态指数角度看,仅凋落物输入处理的线虫群落成熟度指数(MI)最高;各碳源输入处理的分解过程均以细菌分解通道为主。研究表明,土壤线虫群落受到碳源输入变化的调节,仅凋落物输入处理比仅根系输入处理对土壤线虫群落的影响更大。无碳源输入处理的物种多样性明显下降,仅凋落物输入处理的土壤食物网更加稳定。研究结果丰富了森林土壤线虫多样性的研究内容,并为高通量测序技术在土壤线虫方面的研究提供方法和数据的支持。

Effects of different carbon input methods on soil nematode community in freeze-thaw period based on high-throughput sequencing

Research on the influence of change of plant carbon source input pathway on soil biological community is a hot issue in academic circles at present. In order to explore the influence of carbon source input mode on soil nematode community in temperate forest ecosystem, the changes of soil nematode community composition and diversity under different carbon source input modes were analyzed by Illumina MiSeq technology. The results showed that a total of 68 genera of soil nematodes were found in all treatments (Control: CK, Litter removal: NL; Root removal: NR; Litter and root removal: NLR), while the relative abundance of bacterivores was the highest. Among all carbon source input methods, the NR had the most obvious effect on nematode community composition, as shown in the following: compared with control treatment, the relative abundance of bacterivores obviously increased, the relative abundance of fungivores significantly decreased, and the relative abundance of omnivores/predators significantly increased in the NR. From the perspective of nematode community diversity, the NLR reduced the Shannon-wiener index (H'') and increased the dominance (Dom) of soil nematode community. The evenness index (J) of the NR was the highest. From the perspective of nematode community ecological index, the nematode community maturity index (MI) of the NR was the highest. The bacterial decomposition channel was dominant in the decomposition process of all carbon source input treatments. The results showed that soil nematode community was regulated by the change of carbon source input, and the NR had a greater impact on soil nematode community than the NL. The species diversity of soil with the NLR decreased obviously, and the soil food web of the NR was more stable. The results enrich the research content of forest soil nematode diversity, and provide methods and data support for high-throughput sequencing technology in soil nematode research.