| Arbuscular mycorrhizal (AM), as a widespread mutualistic symbionts, has been existence over 400 million years in nature, which not only plays a vital role in plant growth-promoting but also a critical hub connecting the above- and belowground ecosystems. So far, the study of AM fungi has been involved in many ways, but the research about the relationship between AM fungi community and plant phlogeny is limited. In this study, we trying to explore the relationship among plant phylogeny, plant functional traits and AM fungi community with the research of plant phylogeny and functional traits as the starting point. To clarify:1) Whether the close genetic relationship of plants are more similar with AMF community composition in the root? 2) Whether the plant traits (N\P) related with its Phylogeny and AM fungi community? 3) plant phylogeny, plant traits and envrionment which impact AM fungi community more? The study sites chose in the natural grass of XiaMa Forest District, which is located in the eastern Tibetan Plateau of China.42 plant species (belonging to 14 families and 28 generas) were collected from this area in the summer of 2013. Then we measured plant height, specific leaf area, and many other plant physical and chemical properties, and analysis AM fungal biodiversity in each plant root by the means of the 18S rRNA clone library.The main results are as follows:1. One-way ANOVA show that 9 plant traits of the 42 single plant species are significantly different. The phylogenetic signal detection results show that plant water content, plant height and plant N:P have strong phylogenetic signal(K=1.075, P=0.002; K=0.922, P=0.006; K=0.81, P =0.046).Which indicate that these 3 plant properties are affected more significantly by phylogenetic history.2. In this study, a total of 35 AM fungal phylotypes are found in 42 plant species (126 DNA samples). They belong to 6 families and 9 genus. These 6 family are Glomeraceae, Claroideoglomeraceae, Diversisporaceae, Ambisporaceae, Scutellosporaceae and Pacisporaceae. Among them, Glomus which belong to Glomeraceae is a biggest group in the roots of all plant species.3. Correlation analysis showed that:the colonization and AM fungi species richness are significantly positive correlation (Cor=0.39986, P=0.04297) in 26 plants of shady, and related but not significant (Cor=0.455, P=0.076) in 16 plants of sunny. After merging all data of shady and sunny, we found that those two AMF index are significant positive correlation (Cor=0.41486, P=0.00777). This suggests that the species which has high AM fungi colonization is also has high AMF species richness. AMF species richness increased with the increase of AMF colonization.4. AM fungal species richness in different plant speices are notably different and it changes from 1.00±0.57 to 6.67±1.86. Which is relatively high in the plant speices belong to Compositae, Rosaceae and Gramineae. Oppositely, the AM fungal species richness are relatively low in the plant speices belong to Scrophulariaceae and Cyperaceae.5. The results of Mantel Test show that the phylogenetic distance of the 26 plant species in shady slope has a significant positive correlation with community distance of AM fungi(r= 0.1356, P=0.041). But there is no significant correlation in sunny slope at a significant level of 0.05(r=0.1185, P=0.056). When we merged the data of two sample sites. The results show that the phylogenetic distance of the 42 plant species in our sampling sites has a significant positive correlation with community distance of AM fungi (r=0.1904, P=0.003). This shows that close genetic relationship of plants are more similar with AMF community composition in the root.6. NMDS ordination anlysis and fitting of 9 plant function traits found that four of nine plant functional traits are significantly associated with AM fungi community. They are plant tissue total nitrogen content (r2=0.4335, P=0.4335), plant tissue phosphorus (r2=0.3886, P=0.3886), specific leaf area (r2=0.2332, P=0.2332) and the ratio of nitrogen to phosphorus (r2=0.2213, P =0.2213), respectively. These four function traits may related with nutrient exchange between plant and AM fungi.7. The Variance partitioning results show that the plant phylogeny and environment explained 47.61% of the variation of AM fungi community (F=2.313, P=0.002). The plant phylogeny and plant traits could explained 43.864% of the variation (F=2.344, P=0.005), and the environment could explained 3.926% of the variation (F=2.098, P=0.088). This shows that plant phylogeny and plant trait is a major factor to influence AM fungal community structure. |
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