Abstract:

The microbial composition and function in the rhizosphere is the research focus of microbial ecology. Analysis of the diversity of soil microbial communities in the root system of paddy rice and the effects of environmental factors on soil microorganisms can provide reference value for the sustainability of soils in the growing areas of paddy rice and the conservation of land resources. In this study, we used 16S rRNA high-throughput sequencing technology to determine the bacterial composition of soil microorganisms in the rhizosphere of paddy rice, and analyze the composition and diversity of microbial communities sampled from different regions, and explore the relationship between soil microbial diversity and soil physicochemical properties. The results showed that a total of 33862 OTUs, belonging to 38 phylums, 88 orders, 214 orders, 514 families and 2268 genera, were obtained from the paddy rice rhizosphere soil samples collected from the four regions by sequencing. At the phylum level, the dominant phyla of paddy rice rhizosphere soil bacteria collected from the four regions were Proteobacteria, Bacteroidetes and Firmicutes. At the genus level, Limisphaera was the dominant taxon of paddy rice rhizosphere soil bacteria. As shown by the Alpha diversity index, the species diversity and richness of paddy rice inter-root soil bacteria collected from the four regions were generally as followed: 68^th Regiment of the Corps (D)> Dairy Farm of Yili Prefecture (A)> Chabchal Town (B)> Sundzach Niuzhu Township (C); the Beta diversity index indicated that the paddy rice rhizosphere soil collected from the four regions differed accordingly in their bacterial community compositions, with greater differences existed between group A and other groups. The correlation analysis between soil bacteria and environmental factors concluded that the main influencing factors on the composition of microbial bacterial communities in paddy rice rhizosphere soils might be nitrogen, total potassium, and organic carbon. This study clarified the rhizosphere soil conditions and rhizosphere soil bacterial community characteristics of paddy rice distributed in the Ili River Valley, and provided theoretical support for the study of soil ecosystems in the Ili River Valley.

Key words: paddy rice, rhizosphere soil bacteria, diversity indices, high-throughput sequencing, 16S rRNA high-throughput sequencing, environmental factors