Effects of intercropping with Mucuna pruriens var.utilis on sugarcane rhizosphere microbe based on high throughput sequencing

【Objective】The effects of Mucuna pruriens var.utilis intercropping with sugarcane on the microbial diversity in the rhizosphere of sugarcane were investigated, and a theoretical foundation was laid for improving the soil microbial community structure of M.pruriens intercropping with sugarcane and promoting the growth of sugarcane.【Method】A single-factor design experiment was conducted to analyze the microbial community structure of sugarcane rhizosphere soil at the phylum and genus levels by Illumina HiSeq high-throughput sequencing technology under the two planting methods of sugarcane monoculture(CK) and sugarcane intercropping M.pruriens(T treatment), and principal component analysis(PCA) to determine the effect of intercropping M.pruriens on sugarcane rhizosphere soil nutrients.【Result】The contents of total nitrogen, total potassium, hydrolyzable nitrogen, available phosphorus and organic matter in rhizosphere soil of T treatment were higher than those of CK treatment.The richness and diversity of bacteria in the rhizosphere soil of T treatment was higher than that of fungi.The bacterial richness of bacteria in the rhizosphere soil of Ttreatment was higher than that of CK, but the difference was not significant(P> 0.05, the same below), its diversity was significantly higher than that of CK(P< 0.05, the same below).The abundance and diversity of bacteria in the rhizosphere soil under T treatment were significantly higher than that of CK.The dominant phylum of bacteria in CK and T treatments were Proteobacteria, Actinobacteria, Chloroflexi and Acidobacteria, and their relative abundances were more than 10.00%.The dominant bacteria genera were Mizugakiibacter, Luedemannella, Actinothermus and Bruyobacte, but the relative abundances of Mizugakiibacter, Luedemannella, Actinothermus decreased by 2.47%, 1.78% and 0.68%, other bacteria increased by 0.10%-0.86% compared to CK under T treatment.The dominant fungal phyla in the rhizosphere soil of CK and T treatments was Ascomycota, 80.00% and 92.00% respectively, followed by Basidiomycota, 8.00% and 6.00%, the top three dominant fungi genus all belonged to the genus Taifanglania, Chaetomium and Fusarium.Principal component analysis(PCA) of six root soil samples treated with CK and T showed that the variation of bacterial community PC1 was 29.37%, the variation of PC2 was 20.26%, the total contribution rate of both was 49.63%;the variation of fungal community PC1 was 33.44%, the variation of PC2 was 27.73%, the total contribution rate of both was 56.17%.The bacterial communities of CK and T treatment belonged to different quadrants, respectively, CK was located in the 1^st and 3^rd quadrants, and T treatment was located in the 2^nd and 4^th quadrants.【Conclusion】The results show that intercropping sugarcane with M.pruriens improves the soil nutrient status, changes the microbial community structure, and increases the richness and diversity of bacteria and fungi in sugarcane rhizosphere, but does not affect the sequence of dominant microflora.