Research papers
ZHANG Congming, MAN Xiaowu, WU Fang, YUAN Yuan, BIAN Lusen
Pinus tabuliformis and Pinus sylvestris var. mongolica are important afforestation species with different geographical distributions in China. The West Mountain of Beijing is the suitable area for the growth of Pinus tabuliformis, but is the southern extremity of distribution of P. sylvestris var. mongolica, therefore it is an ideal research site to explore the driving role of tree species in the construction of microbial community in soil-plant continuum. In this study, high-throughput sequencing technology was used to obtain the composition of microbial communities in several parts of the soil-plant continuum of plantations of P. tabuliformis and P. sylvestris var. mongolica in West Mountain of Beijing. The role of species factors in the construction of soil-plant continuum microbial community of these two pine trees was explored, and the physicochemical properties of soil closely related to soil microorganisms were further studied. The results showed that the difference of alpha diversity of microbial community in soil-plant continuum between the two pine was mainly reflected in bulk soil and rhizosphere soil. The beta diversity analysis showed that the bacterial community composition in needle was not significant difference between the two pine, while the microbial community composition in other parts of tree was different between the two pine. Tree species had the highest explanation for the variance of soil and rhizosphere microbial community composition, while the lowest explanation for the variance of needle microbial community composition, in other words, tree species played a larger role in the construction of soil and rhizosphere microbial community, but a smaller role in the construction of needle endophytic microbial community. The network structure of bacterial communities in the same part of tree was more complex in P. tabuliformis than in P. sylvestris var. mongolica, but the fungal network had less differences between the two pines. Abundant microbial groups in the tissues and soil of P. tabuliformis and P. sylvestris var. mongolica were found. At class level, the relative abundance greater than 5% was considered as dominant class. Seven bacterial classes, Alphaproteobacteria, Betaproteobacteria, Actinobacteria, Thermoleophilia, Gammaproteobacteria, Bacilli, and Clostridia, and seven fungal classes, Agaricomycetes, Leotiomycetes, Sordariomycetes, Eurotiomycetes, Dothideomycetes, Mortierellomycetes, and Pezizomycetes, were recognized. Significant differences in soil physicochemical properties, e.g. available phosphorus (AP), pH and available kalium (AK), were found between the plantations of P. tabuliformis and P. sylvestris var. mongolica, and these properties effect soil microbial diversity and composition between the two pines. In addition, alkali-hydrolyzed nitrogen (AHN) was also significantly correlated with the composition of the bacterial community. The results demonstrate the interactions between pines and microorganisms and the mechanism of microbial community construction, and provide reference data on microbial community in pine plantations in northern China.