---

Seasonal variation rather than stand age determines bacterial diversity in the rhizosphere of wolfberry (Lycium barbarum L.) associated with soil degradation

Authors Zhang, Junhua; Li, Ming; Jia, Keli; Zheng, Guoqi; Long, Xi-En

Journal JOURNAL OF SOILS AND SEDIMENTS , APR 2018,4:18

DOI 10.1007/s11368-017-1854-6

Abstract Soil degradation occurs in wolfberry (Lycium barbarum L.) fields with increasing stand age, but the effect of stand age on rhizosphere microbial communities is unclear. We examined the seasonal variation of rhizosphere bacterial communities under long-term cultivation of L. barbarum.We determined surface (0-20 cm) and subsurface (20-40 cm) soil properties in L. barbarum rhizosphere at four stand ages (3-15 years) across three growth seasons (spring-autumn). Soil bacterial communities were characterized by 16S rRNA high-throughput sequencing.Soil nutrient availability in the surface was higher than that in the subsurface. Total soil organic carbon (TOC), nitrogen (TN), and phosphorus (TP) occurred at the highest levels in the summer across different stand ages. Soil bacterial diversity in the autumn was lower than that in the spring and summer. More diverse communities were found at stand ages of 3 and 6 years compared with 9 and 15 years. The relative abundance of Proteobacteria was highest in the summer, whereas the relative abundance of Bacteroidete at stand age of 9 years was significantly higher than those at other stand ages across different seasons. Xanthomonadaceae abundance increased with stand age, while Bacillus and Pirellulaceae abundances decreased in the spring and summer compared with autumn. Soil electric conductivity was a key edaphic factor for the rhizosphere bacterial community structure.Seasonal fluctuation, rather than stand age, determines soil bacterial diversity in the rhizosphere of L. barbarum associated with soil degradation under long-term cultivation of L. barbarum.

Species covered 黄果枸杞 Lycium barbarum