太子参不同休耕年限土壤理化特征和微生物群落变化

太子参为福建道地中药材,连作效应严重限制其产业发展。休耕可以在一定程度上缓解连作效应,然而休耕对于缓解连作效应的机制尚不清楚。本文通过高通量测序分析不同休耕年限对太子参土壤微生物丰度及群落多样性的影响,并探索土壤理化性质、酚酸类物质与土壤微生物群落之间的关联性。结果表明:与对照太子参土壤相比,休耕土壤真菌多样性降低,细菌多样性增多。在细菌优势菌门中,酸杆菌门相对丰度显著增加,变形菌门与放线菌门相对丰度显著降低;真菌优势菌门相对丰度无显著变化。土壤酸性减弱,有机质含量随休耕年限增加呈现递减模式,酚酸类物质中苯甲酸和水杨酸含量显著降低,而对香豆酸等逐渐积累。综上,太子参土壤休耕改善了土壤微生物的菌群结构、土壤性质,从而缓解了连作效应。

Changes in physicochemical property and microbial community of Pseudostellaria heterophylla soil at diffe-rent fallow ages

Pseudostellaria heterophylla is authentic traditional Chinese herbal medicine in Fujian Province. P. hete-rophylla suffers from serious consecutive monoculture problems. Fallow can alleviate such problems, but the mecha-nism is still unclear. In this study, high-throughput sequencing was performed to analyze the changes in soil microbial community structure and diversity in the P. heterophylla soil at different fallow ages as well as their relationships with soil physicochemical properties and phenolic acids. The results showed that fungal community diversity decreased but bacterial community diversity increased in fallow soils compared with the control soil of P. heterophy-lla. For bacterial communities, the relative abundance of Acidobacteria increased, while that of Proteobacteria and Actinobacteria decreased in fallow soils. For fungal communities, the relative abundance of dominant phyla had no significant difference between fallow and control soils. Soil acidity and organic matter content showed a trend of weakening and decreasing, respectively, with the increases of fallow years. In addition, with the increases of fallow years, the content of phenolic acids in soil, including benzoic acid and salicylic acid, showed significant decrease, while some other phenolic acids such as p-coumaric acid were accumulated obviously. Taken together, fallow could efficiently ameliorate the structure of soil microbial community and soil properties of P. heterophylla, and thus alleviate the effects of continuous cropping.