宁夏中部干旱带不同作物根际土壤真菌群落多样性及群落结构

Fungal community diversity and structure in rhizosphere soil of different crops in the arid zone of central Ningxia

【背景】宁夏中部干旱带常年缺水,植被稀疏,土地沙漠化严重,生态环境十分脆弱。土地沙漠化导致土地生产力下降,制约着该区农业的发展,因此,改善宁夏中部干旱带农田生态环境具有重要意义。【目的】为该区土地资源的合理利用开发及干旱区土壤真菌多样性的深入研究提供基础数据和理论依据。【方法】运用IlluminaMiSeq高通量测序技术对宁夏中部干旱带农田作物土壤真菌种类进行预测,并对其进行真菌多样性和群落结构的分析。【结果】5个处理中真菌种类均较为丰富,丰富度指数无差异;真菌多样性指数分别以‘张杂谷5号’谷子最高,藜麦的多样性最低,且存在极显著差异。不同作物根际土壤中,子囊菌门(Ascomycota)为最优势菌门,相对丰度为73.00%-89.14%,且远远大于次优势菌门--担子菌门(Basidiomycota,3.9%-16.5%),表现出非常明显的优势;支顶孢属(Acremonium)和裂壳菌属(Schizothecium)为共有的优势菌属。土壤速效磷和土壤碱解氮会对土壤真菌群落结构和功能多样性产生影响,土壤微生物群落结构、功能多样性的变化是土壤理化性质与微生物相互作用的结果。【结论】休闲和种植作物的农田土壤养分均可不同程度的提高,土壤pH降低,真菌群落结构和多样性发生变化。说明合理的土地利用有利于丰富农田土壤微生物群落结构和多样性,改良土壤特性,进而促进该区域土壤生态系统的稳定,提高农田土地资源的合理利用。

[Background] The arid zone in central Ningxia is characterized by perennial water shortage,sparse vegetation, serious desertification and fragile ecological environment. Land desertification leads to the decline of land productivity and restricts the development of agriculture in this area. Therefore, it is of great significance to improve the farmland ecological environment in the arid zone of central Ningxia. [Objective] In order to provides basic data and theoretical basis for the rational utilization and development of land resources and the further study of soil fungal diversity in arid areas. [Methods] This research used Illumina MiSeq high-throughput sequencing technology to study the species and diversity of soil fungi, and analyze the fungal diversity index and community structure. [Results] Among the five treatments, fungi species were abundant and richness index had no difference. The diversity index of fungi was highest in Zhangzagu No. 5 millet and lowest in quinoa, and there were significant differences. Ascomycota was the most dominant phylum in the rhizosphere soil of different crops, and the relative abundance ranged from 73.00% to 89.14%, which was much larger than the subdominant phylum--Basidiomycota(3.9%-16.5%) and showed a very obvious advantage;Apart from that Acremonium and Schizothecium were common dominant genera. Through DCA correspondence analysis and correlation analysis, it was found that soil available phosphorus and soil alkali-hydrolyzed nitrogen affected the structure and functional diversity of soil fungi community. The change of soil microbial community structure and functional diversity was the result of interaction between soil physical and chemical properties and microorganisms. [Conclusion] The soil nutrients of recreational and crop-growing farmland can be increased in different degrees, the soil pH decreases, and the fungal community structure and diversity change. It shows that rational farmland use is conducive to enriching the structure and diversity of soil microbial community, improving soil characteristics, and then promoting the stability of soil ecosystem in the region, and improving the rational utilization of farmland land resources.