内蒙古砒砂岩地区沙棘根际和非根际土壤理化性质及真菌群落特征

Physicochemical properties and fungal community characteristics of rhizosphere and non-rhizosphere soils of Hippophae rhamnoides in Pisha sandstone area of Inner Mongolia

摘要:

【目的】以内蒙古砒砂岩区沙棘林为研究对象，探究不同年限沙棘林根际土壤与非根际土壤的理化性质差异，同时分析真菌群落结构差异，并进一步探究两者之间的相互关系。【方法】在内蒙古鄂尔多斯砒砂岩区采集了不同年限沙棘林根际与非根际共计12个土壤样品，采用传统土壤环境指标测定方法测定土壤理化性质，利用高通量测序方法分析土壤真菌群落结构特征，同时分析两者之间的相互关系。【结果】根际土壤全氮、碱解氮、速效钾、有机质和电导率显著高于非根际土壤(P<0.05)，随着种植年限的增长，土壤含水率显著增加(P<0.05)。根际土壤群落丰富度和多样性整体高于非根际。子囊菌门(Ascomycota)、被孢霉门(Mortierellomycota)为共有优势菌门；被孢霉属(Mortierella)、青霉菌属(Penicillium)、曲霉菌属(Aspergillus)为共有优势菌属。非根际真菌群落的关键类群是被孢霉属(Mortierella)，根际真菌群落的关键类群是赤霉菌属(Gibberella)。冗余分析表明，土壤有机质是影响土壤真菌群落分布的关键因素。被孢霉属(Mortierella)与有机质、碱解氮和全钾之间具有显著相关性(P<0.05)；赤霉菌属(Gibberella)与碱解氮、有机质和电导率之间具有显著相关性(P<0.05)。【结论】内蒙古砒砂岩沙棘林种植提高了根际土壤养分和真菌群落的丰富度，促进了土壤生态环境的稳定性。沙棘的种植也提高了该种植地的土壤含水率，促进水土保持，有助于该地区的生态恢复和建设。本研究不仅为该地区的生物多样性保护提供理论依据，更为促进沙棘林生态恢复效果和可持续管理提供科学依据和数据支持。

关键词:根际土壤;沙棘林;土壤真菌;群落结构;土壤理化性质

Abstract:

[Objective] To compare the physicochemical properties and fungal community characteristics between rhizosphere soil and non-rhizosphere soil of Hippophae rhamnoides growing for different years in Pisha sandstone area of Inner Mongolia. [Methods] A total of 12 rhizosphere and non-rhizosphere soil samples were collected from the Pisha sandstone area of Ordos. Chemical methods were used to analyze soil physicochemical properties, and the fungal community composition in soil was analyzed by high-throughput sequencing. The correlations between fungal community characteristics and soil properties were analyzed. [Results] Total nitrogen (TN), available nitrogen (AN), available potassium (AK), organic matter (OM), and electrical conductivity (EC) of rhizosphere soil were higher than those of non-rhizosphere soil (P<0.05). Soil moisture content (SMC) increased as the planting years increased (P<0.05). The fungal richness and diversity in rhizosphere soil were higher than those in non-rhizosphere. Ascomycota and Mortierellomycota were the common dominant phyla in rhizosphere soil and non-rhizosphere soil, and Mortierella, Penicillium, and Aspergillus were the common dominant genera. The key fungal groups in non-rhizosphere soil and rhizosphere soil were Mortierella and Gibberella, respectively. The redundancy analysis showed that OM was a key soil factor affecting the soil fungal distribution. Mortierella was correlated with OM, AN, and total potassium (TK) (P<0.05). Gibberella was correlated with AN, OM, and EC (P<0.05). [Conclusion] The planting of H. rhamnoides in Pisha sandstone area of Inner Mongolia increases the nutrients and fungal richness in the rhizosphere soil, improving the stability of the soil environment. Moreover, the cultivation of H. rhamnoides increases the soil moisture, improving soil and water conservation and contributing to the ecological restoration. This study provides a theoretical basis for biodiversity conservation in the study area as well as for the ecological restoration and sustainable management of H. rhamnoides shrubland.

Key words:rhizosphere soil;Hippophae rhamnoidesshrubland;soil fungi;community structure;soil physical and chemical properties