Objective  To provide a theoretical basis for improving soil management measures of rain shelter treatment, the effects of rain shelter treatment on the bacterial community of pear tree rhizosphere soil were studied.

  Method  The fruit qualities, and soil chemical properties and taxonomic composition of bacteria communities were determined under rain-shelter treatment and open field treatment in the same pear orchard. The correlation between bacterial communities in the rhizosphere of pear trees and the physio-chemical and fruit quality indicators under different treatments were analyzed.

  Result   The results of pear fruit quality showed that the content of sucrose and reducing sugar under rain-shelter treatment were increased by 1.83 times and 1.08 times, respectively, as much that under open field treatment. The content of vitamin C and total acid under rain-shelter treatment were significantly decreased by 1.23 times and 1.20 times, respectively, as much that under open field treatment. Compared with open field treatment, the ratio of sugar to acid in rain-sheltered treatment increased significantly and fruit quality was better. The results of soil chemical properties of pear orchard showed that the contents of available phosphorus, available potassium, organic matter and water content in the rain shelter treatment were significantly lower than those in the open field treatment, while the total nitrogen was significantly higher than that in the open field treatment. Sequencing analysis of rhizosphere soil microorganisms showed that the main bacterial communities in the rhizosphere soil of pear trees under rain shelter treatment were Proteobacteria, Acidobacteria, Chloroflexi and Actinobacteria at the phylum level. Uncultured bacterium, uncultured forest soil bacterium and uncultured proteobacterium were the main bacterial communities in the rhizosphere of pear trees in the open field. Rain-shelter treatment significantly increased rhizosphere microbial diversity and richness. Correlation analysis showed that the rhizosphere microbial diversity was positively correlated with total nitrogen, available nitrogen and pH value, but was negatively correlated with total potassium, total phosphorus, available potassium, available phosphorus, organic matter and water content, and was positively correlated with sucrose and reducing sugar content.

  Conclusion  Rain-shelter cultivation can promote the diversity and richness of microorganisms, enhance the stability of the rhizosphere micro-ecological environment. Rain-shelter treatment is conducive to the growth of pear trees and the formation of fruit yield and quality, but it was disadvantageous to soil material circulation. Proper open shelter cultivation could make use of soil material circulation in pear orchard and improve the sustainability of pear orchard production.