当归不同生长时期根际土壤酶活性及微生物群落结构变化

Changes in Rhizosphere Soil Enzymatic Activities and Microbial Communities across Growth Stages of Angelica sinensis

【目的】研究当归(Angelica sinensis)不同生长时期根际土壤酶活性和微生物群落结构的动态变化及其关联性,为当归的健康种植和土壤改良提供科学依据。【方法】以甘肃产当归的根际土壤为研究对象,研究5个生长时期当归根际土壤5种初级代谢酶活性,并运用高通量测序对细菌和真菌群落门、属水平的变化进行研究。【结果】当归根际土壤细菌群落丰富度和均匀度不随生长时期变化,而真菌群落变化显著;生长后期细菌和真菌群落结构与前中期明显分离,这种分离主要由部分菌门和菌属丰度显著变化造成;细菌属间多以互利共生关系存在,细菌与真菌间更倾向于以此消彼长的关系存在;抽薹期根际土壤蔗糖酶活性最低,脲酶活性最高,相关性分析表明,细菌对酶活性的影响高于真菌,其中蔗糖酶与黄杆菌属(Flavobacterium)显著正相关,脲酶与拟杆菌属(Bacteroides)、毛壳菌属(Chaetomium)显著正相关,与马赛菌属(Massilia)、鞘脂菌属(Sphingobium)、Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium属、新鞘脂菌属(Novosphingobium)显著负相关;酸性磷酸酶、淀粉酶、过氧化氢酶在不同时期维持稳定,而鞘氨醇单胞菌属(Sphingomonas)、拟杆菌属(Bacteroides)、MND1属、芽单胞菌属(Gemmatimonas)和溶杆菌属(Lysobacter)在维持其活性上发挥着一定的作用。【结论】该研究反映出当归根际土壤细菌-真菌群落在其生长发育过程中的动态平衡,酶和菌属的生长周期波动及其关联性反映出与当归抽薹可能相关的酶和菌属,以及维持酶稳定的有关菌群。该研究为下一步当归促生菌的筛选及功能验证提供了科学参考。

[Objective] The objective of this study is to research the dynamic changes and correlation of rhizosphere soil enzyme activities and microbial community structure in different growth stages of Angelica sinensis, so as to provide scientific basis for healthy planting and soil improvement of Angelica sinensis. [Method] Taking the rhizosphere soil of A. sinensis in Gansu Province as the research object, the activities of five primary metabolic enzymes and the changes of phylum and genus levels of bacterial and fungal communities by high-throughput sequencing were studied in five growth periods. [Result] It was found that the richness and evenness of bacterial community in rhizosphere soil of A. sinensis did not change with growth periods, but the fungal community changed significantly. The community structure of bacteria and fungi in the late growth stages were significantly separated from that in the early and middle stages, which were mainly caused by the significant changes in the abundance of some phylum and genus. The relationship between bacteria tends to be mutually beneficial symbiotic, but between bacteria and fungi tends to be negative correlation. The invertase activities of rhizosphere soil were the lowest and urease activities were the highest at bolting stage. The correlation analysis showed that the effect of bacteria on enzyme activities was higher than that of fungi. Invertase was significantly positively correlated with Flavobacterium,urease was significantly positively correlated with Bacteroides and Chaetomium, and was significantly negatively correlated with Massilia, Sphingobium, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium and Novosphingobium. Acid phosphatase, amylase and catalase remained stable in different periods. Sphingomonas,Bacteroides, MND1, Gemmatimonas and Lysobacter played an important role in maintaining their activities.[Conclusion] This study reflects the dynamic balance of bacterial-fungal community in A. sinensis rhizosphere soil during its growth and development. The growth cycle fluctuation and correlation of enzymes and bacteria reflect some enzymes and bacteria those may be related to A. sinensis bolting, and the relevant bacteria that maintain enzyme stability. This study provides a scientific reference for the screening and functional verification of growth promoting bacteria of A. sinensis in the next step.