Characteristics of microbial community in the rhizosphere soil of continuous potato cropping in arid regions of the Loess Plateau

Abstract

<p id="C4">The response of soil microorganisms to continuous cropping of potato was discussed in this study, aiming at revealing the microbial characteristics of continuous cropping soil degradation. Pot experiments and MiSeq high-throughput sequencing technology were used to study the characteristics of microbial communities in the rhizosphere soil of potato continuous cropping for 1 year (1_rh), 3 years (3_rh), and 5 years (5_rh), with fallow (CK) and rotation (R_rh) as controls. The results showed that compared with CK and rotation, Ace index, Chao index, and Shannon index of 3_rh and 5_rh soil samples decreased significantly. Compared with rotation, the relative abundance of Proteobacteria, Actinobacteria, and Acidobacteria in soil bacteria of continuous potato cropping was higher, while the relative abundance of Ascomycota in soil fungi was lower. In the bacterial community, compared with rotation, the number of <italic>Aeromicrobium</italic> in 1_rh, 3_rh, 5_rh increased by 258.01%, 625.93%, 76.04%, <italic>Arthrobacter</italic> increased by 245.42%, 1258.12%, 58.89%, <italic>Streptomyces</italic> increased by 203.83%, 116.74%, and 311.61%, respectively. In the fungal community, compared with rotation, the number of <italic>Fusarium</italic> in 3_rh increased by 225.00%, the number of <italic>Chaetomium</italic> in 5_rh decreased by 31.58%, and the number of <italic>Guehomyces</italic> in 1_rh, 3_rh, and 5_rh decreased by 55.40%, 58.14%, and 78.37%, respectively. <italic>Spizellomyces</italic> had a large number in fallow and rotation soils, but a small number in continuous cropping soils for three years and five years, which was close to the detection limit. The results indicated that long-term continuous cropping of potato reduced the diversity of soil microorganisms, changed the dominant population of microorganisms, and unbalanced the structure of soil microbial community.