内蒙古大青山灌木铁线莲根围丛枝菌根真菌群落季节动态研究

采用Illumina MiSeq测序技术研究了内蒙古大青山干旱阳坡灌木铁线莲(Clematis fruticosa)根围丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)群落的季节动态,并利用冗余分析(redundancy analysis,RDA)和Mantel test分析了土壤和植被因子与AMF之间的关系,为进一步探索灌木铁线莲-AMF共生体对不同季节环境变化的响应提供理论依据。结果表明:(1)灌木铁线莲根围AMF孢子密度不存在显著的季节性差异,根系侵染率和丛枝丰度从春季至秋季呈下降趋势。(2)3个季节共检测出163个AMF OTUs(operational taxonomic units),春季、夏季、秋季分别为116OTUs、76OTUs和70OTUs。(3)夏季和秋季的AMF丰富度(实测OTUs数和Chao1指数)以及多样性(Shannon-Wiener指数和Invsimpson指数)显著低于春季,但夏、秋季间无显著异。(4)主成分分析和PERMANOVA分析表明,夏季和秋季的AMF群落组成与春季存在显著差异,而AMF群落组成在夏季与秋季间差异不显著。(5)RDA分析表明,采样季节、植被盖度、植物多样性、土壤含水量和土壤有机质对AMF ShannonWiener指数、Invsimpson指数、Chao1指数和实测OTUs数均产生显著影响;Mantel test分析发现,采样季节是影响AMF群落组成和菌根侵染率的主导因子,但对孢子密度无显著影响,而土壤有机质是影响孢子密度的主导因子。

Seasonal Dynamics of Arbuscular Mycorrhizal Fungal Community in the Rhizosphere of Clematis fruticosa in the Daqingshan Mountains, Inner Mongolia

With the method of Illumina MiSeq sequencing, we investigated the seasonal dynamics of arbuscular mycorrhizal fungal community in the rhizosphere of Clematis fruticosa in the arid sunny slopes of the Daqingshan Mountains. By the methods of redundancy analysis (RDA) and Mantel test, we also analyzed the relationships between AMF and soil and plant factors. It would provide important scientific basis to further discuss the response of C. fruticosa AMF symbioses to climate changes in different seasons. The results indicated that: (1) Spore density of AMF was no significant difference among seasons, but colonization rate and arbuscule abundance of AMF had a decreasing trend from spring to autumn. (2) A total of 163 AMF OTUs (operational taxonomic units) were detected in three seasons, 116 OTUs, 76 OTUs and 70 OTUs were detected in spring, summer and autumn, respectively. (3) AMF richness (Observed OTUs and Chao 1 index) and diversity (Shannon Wiener index and Invsimpson index) of summer and autumn were significantly lower than that of spring, but there were no significant differences between summer and autumn. (4) Principal coordinate analysis and PERMANOVA analyses indicated that AMF community compositions of summer and autumn were significantly different from that of spring, while the difference was not significant in summer and autumn. (5) RDA analysis showed that sampling season, plant coverage, plant diversity, soil moisture content and soil organic matter significantly influenced Shannon Wiener index, Invsimpson index, Chao 1 index and Observed OTUs of AMF. Mantel test indicated that sampling season was the driving factor to affect community composition and colonization rate of AMF, but had no significantly influence on spore density, soil organic matter was the driving factor to influence spore density.