中国特有植物青檀和任豆根际土壤微生物多样性的比较

Comparison of Microbial Diversity in the Rhizosphere Soil of Chinese Endemic Plants Pteroceltis tatarinowii and Zenia insignis

摘要: 为了分析中国特有植物青檀和任豆根际土壤微生物多样性的差异，以自然植被青檀和人工植被任豆为研究对象，将常规的研究手段与高通量测序技术相结合，通过比较分析的方法，说明青檀和任豆样地土壤理化性质的差异，及其与根际土壤细菌多样性的相关性。结果表明，1) 不同植被土壤细菌群落结构存在一定的差异，任豆样地的土壤细菌群落结构比较复杂，种群数量相对较大；青檀样地的土壤细菌群落结构比较简单，其种群数量相对较少；2) 青檀和任豆样地的优势菌群相同，但相对丰度有差异，相对丰度排名前5的优势菌门依次为变形菌门，放线菌门，绿弯菌门，酸杆菌门及拟杆菌门。在以上5个优势菌门中，除放线菌门外，任豆的土壤细菌相对丰度均大于青檀；3) 从不同植被调查样地的土壤细菌alpha多样性比较，Chao1指数、Observed OTUs指数、Shannon指数均为任豆大于青檀，其在四个不同分组中的高低排序为RDFGJT > RDGJT > QTGJT > QTFGJT，但青檀的Simpson指数高于任豆，其高低排序为QTFGJT > QTGJT > RDFGJT > RDGJT；4) 岩溶地区土壤的空间异质性较大，同一树种非根际土壤和根际土壤距离相近，其微生物群落结构相似度较高，差异较小；不同树种的空间距离较远，其微生物群落相似度较低，差异较大。因此，青檀与任豆根际土壤细菌多样性有较明显的差异。

Abstract: In order to analyze the differences of microbial diversity in the rhizosphere soil of Pterocarpus tatarinowii and Zenia insignis, two endemic plants in China, P. tatarinowii and Z. insignis, were taken as the research objects, and the conventional research methods were combined with hi- gh-throughput sequencing technology. Through comparative analysis, the differences of soil phys-ical and chemical properties between P. tatarinowii and Z. insignis, and their correlation with the bacterial diversity in the rhizosphere soil were explained. The results indicate that 1) there are certain differences in the soil bacterial community structure among different vegetation types. The soil bacterial community structure in the Z. insignis plot is relatively complex, with a relatively large population size; the soil bacterial community structure of P. tatarinowii plot is relatively simple, and its population is relatively small; 2) The dominant flora of P. tatarinowii and Z. insignis sampling plots are the same, but the relative abundance is different. The top five dominant bacteria in the relative abundance ranking are Proteobacteria, Actinomycetes, Chloroflexi, Acidobacteria and Bacteroidetes. Among the five dominant bacterial phyla mentioned above, except for Actinomycetes, the relative abundance of soil bacteria in Z. insignis is greater than that in P. tatarinowii; 3) From the comparison of soil bacterial alpha diversity in different vegetation survey plots, the Chao1 index, Observed OTUs index, and Shannon index were all higher in Z. insignis than that in P. tatarinowii. In the four different groups, the high-low order was RDFGJT > RDGJT > QTGJT > QTFGJT. However, the Simpson index of P. tatarinowii was higher than that of Z. insignis, and the high-low order was QTFGJT > QTGJ T> RDFGJT > RDGJT; 4) The spatial heterogeneity of soil in karst area is large, the distance between non rhizosphere soil and rhizosphere soil of the same tree species is similar, and the similarity of microbial community structure is high, but the difference is small; The spatial distance of different tree species is relatively long, and their microbial communities have low similarity and significant differences. Therefore, there is a significant difference in bacterial diversity in the rhizosphere soil between P. tatarinowii and Z. insignis.