内蒙古荒漠草原土壤可培养真菌的群落结构和空间分布分析

摘要

为了揭示荒漠草原土壤可培养真菌的群落结构和空间分布,以实现利用微生物对环境变化的敏感性对退化草地提前预测和有效管理,采用稀释平板涂布法和18S rRNA分子鉴定技术对内蒙古荒漠草原土壤可培养真菌的群落结构、多样性、空间分布及其与土壤环境因子的相关性进行分析.结果表明:可培养真菌在0～30 cm土层的数量为26.65×104～90.69×104 CFU·g-1,各土层的真菌分布次序为:0～10 cm＞10～20 cm＞20～30 cm.分离到的真菌分别属于14个属,其中青霉菌属是优势菌属,占0～30 cm可培养真菌总数的48.76％,其次是曲霉属,占可培养真菌总数的10％.在0～10 cm土层,可培养真菌的物种丰富度和Shannon-Wiener指数(H)最高.可培养真菌的数量与含水量、速效钾和铵态氮呈显著正相关关系(P＜0.05);与有机质含量呈极显著正相关关系(P＜0.01),与pH值呈显著负相关关系(P＜0.05);与硝态氮和速效磷无显著相关性.%In order to assess the community structure and spatial distribution of cultivable fungi in desert steppe,Inner Mongolia,China,dilution plate method and 18S rRNA molecular identification technique were used to study the community composition,distribution and diversity of cultivable fungi.Pearson's correlation was used to analyze the relationships between the quantity of fungi and soil physical and chemical factors.The quantity of cultivable fungi was 26.65 × 104 ～ 90.69 × 104 CFU · g-1 in 0 ～ 30 cm soil depth.The distribution trend of cultivable fungi was 0～10 cm＞10～20 cm＞20～30 cm.Cultivable fungi isolated from desert steppe soil belonged to 14 genus including Penicillium,Fusarium,and so on.The dominant strains were Penicillium and Aspergillus,which relative abundances in 0～30 cm soil layer were 48.76％ and 10％,respectively.Compared with other two soil layers,the species richness and ShannonWeiner Index(H') of cultivable fungi were the highest in 0～10 cm soil depth.The distribution of cultivable fungi had a significant correlation with water content,NH4+-N,available potassium,and soil organic matter content,while it had a significantly negative correlation with pH value.It had no significant correlation with available phosphorus and NO3--N content.