云南岩溶断陷盆地土地利用方式对丛枝菌根真菌群落结构的影响

Influence of land use patterns on arbuscular mycorrhiza fungi community structure in the karst graben basin of Yunnan province, China

摘要:

【背景】丛枝菌根真菌(arbuscular mycorrhizal fungus，AMF)是一类能与绝大部分植物形成共生关系的真菌，在植被演替和生态恢复过程中发挥重要作用。【目的】了解云南岩溶断陷盆地不同土地利用方式对AMF群落结构的影响。【方法】采用Illumina HiSeq 2500高通量测序技术对云南岩溶断陷盆地林地、灌丛和草地等3种土地利用方式土壤样品的AMF群落结构进行分析。【结果】草地总磷(total phosphorus，TP)、速效钾(available potassium，AK)、交换性镁(exchangeable magnesium，E-Mg)、电导率(electrical conductivity，EC)和土壤温度(temperature，T)显著高于林地和灌丛，林地总氮(total nitrogen，TN)和有机碳(soil organic carbon，SOC)含量显著高于灌丛和草地。TN、SOC、AK和EC是AMF群落结构最主要的影响因子。草地样品的Chao1、ACE、Shannon和Observed species指数显著高于林地和灌丛样品，尽管Simpson指数差异不显著，但是也表现出了类似的变化趋势。9个土壤样品共产生953个AMF-OTU，鉴定出AMF 3个纲4个目9个科13个属。Glomeromycetes和Paraglomeromycetes为优势纲；Glomus和Paraglomus为优势属，其次为Claroideoglomus、Acaulospora和Diversispora。Glomus和Diversispora主要分布在草地和灌丛中，随着演替的进行其相对丰度有所下降，而Paraglomus的相对丰度逐渐上升。【结论】云南岩溶断陷盆地土地利用方式的AMF群落结构具有显著差异，土壤理化因子是重要的影响因素。

Abstract:

[Background] Arbuscular mycorrhizal fungus (AMF) can form mycorrhizal symbiosis with most of the plants, to play an important role in vegetation succession and ecological restoration process. [Objective] To reveal the influence of land use patterns on AMF communities in the karst graben basin of Yunnan province, China. [Methods] Soils collected from woodland, shrubland and grassland in the karst graben basin of Yunnan province were used to study the influence of land use patterns on AMF communities based on next-generation sequencing. [Results] Total phosphorus, available potassium, exchangeable magnesium, and electrical conductivity in the grassland were significantly higher than those in the woodland and shrubland, yet total nitrogen and soil organic carbon in the woodland were higher than those in the shrubland and grassland. Soil organic carbon, total nitrogen, and available potassium were the most important factors affecting AMF communities. Chao1, ACE, Shannon and observed species indices in the grassland were significantly higher than those in the woodland and shrubland. Simpson index has no significant difference among land use patterns, but it was higher than those in the woodland and shrubland. Among the nine soil samples, AMF belonged to 953 OTUs, 3 classes, 4 orders, 9 families and 13 genera. Glomeromycetes and Paraglomeromycetes were the dominant class. Glomus and Paraglomus were the dominant genus, followed by Claroideoglomus, Acaulospora and Diversispora. Among the nine soil samples, Glomus and Diversispora were mainly distributed in grassland and shrubland, the relative abundance of Glomus and Diversispora population decreased with vegetation succession process, and the relative abundance of Paraglomus increased. [Conclusion] The AMF communities was significant different among land use patterns. The fungi communities were mostly affected by soil physicochemical properties in the karst graben basin of Yunnan province.