不同连作年限草莓根际细菌和真菌多样性变化

Biodiversity of bacteria and fungi in rhizosphere of strawberry with different continuous cropping years

摘要:

【目的】以不同连作年限草莓根际土壤为材料，探讨不同连作年限土壤细菌、真菌多样性的变化，以期为草莓连作障碍调控提供理论依据。【方法】将没有连作(CK)、连作1年(1Y)、连作8年(8Y)的土壤分别与珍珠岩以3:1的体积充分混匀装盆，“宁玉”草莓苗于2016年9月10日定植于盆栽土壤中，定植后50 d时(开花前)进行土壤取样，提取基因组DNA，通过PCR扩增建立文库，利用Miseq平台Illumina第二代高通量测序技术并结合相关生物信息学方法，分析土壤细菌16S rRNA基因V4+V5区域和真菌ITS1+ITS2区域的丰富度和多样性指数以及群落结构。【结果】从9个草莓根际土壤样本中获得3 192个细菌分类操作单元OTU和762个真菌OTU，其中，变形菌门、厚壁菌门、放线菌门、拟杆菌门和蓝藻门为草莓根际土壤的优势菌种，在CK、1Y、8Y草莓根际土壤中分别占细菌总数的87.86%、64.83%和61.79%；子囊菌门和担子菌门为优势真菌，在CK、1Y、8Y草莓根际土壤中分别占真菌群落的69.17%、69.06%和76.18%。从门的分类水平看，酸杆菌门、放线菌门、拟杆菌门、厚壁菌门、绿弯菌门、蓝菌门、浮霉菌门、芽单胞菌门、变形菌门以及真菌担子菌门、接合菌门、壶菌门的比例在不同连作年限的草莓根际土壤中显著改变(p<0.05)。属水平的分析也表明，共有29个细菌属和19个真菌属的比例发生改变(p<0.05)。【结论】随连作年限的延长，草莓根际土壤生态系统中细菌和真菌群落各门类组成的比例会发生显著变化。

Abstract:

[Objective] The aim of this study was to explore the changes of soil bacteria and fungal diversity with strawberry rhizosphere soil of different continuous cropping years, to provide theoretical basis for the control of strawberry continuous cropping obstacles. [Methods] The soils without continuous cropping (CK), continuous cropping for 1 year (1Y) and continuous cropping for 8 years (8Y) were separately mixed with perlite in a ratio of 3:1. ‘Ningyu’ strawberry plants were transplanted in the potted soil on 10th of September in 2016; soil samples were collected 50 d after transplanting (before flowering); genomic DNA was extracted, and PCR was amplified to establish libraries. The 16S rRNA genes V4+V5 regions of soil bacteria and fungal ITS1+ITS2 regions were sequenced by Illumina high-throughput sequencing technology on Miseq platform, and related biological analysis was conducted to explore the changes of soil bacterial and fungal abundances, diversities and structures. [Results] A total of 3 192 bacterial operational taxonomic units (OTUs) and 762 fungal OTUs were obtained from 9 strawberry rhizosphere soil samples. Among them, Proteobacteria, Fimicutes, Actinobacteria, Bacteroidetes and Cyanobacteria were the dominant bacteria, which abundances of total bacteria were 87.86%, 64.83% and 61.79% respectively in strawberry rhizosphere soil of CK, 1Y, 8Y. Ascomycota and Basidiomycota were dominant fungi, which abundances of fungal community were 69.17%, 69.06% and 76.18% respectively in strawberry rhizosphere soil of CK, 1Y, 8Y. At phylum level, the ratios of Acidobacteria, Actinobacteria, Bacteroidetes, Fimicutes, Chloroflexi, Cyanobacteria, Planctomyces, Gemmatimonadetes, Proteobacteria, Ascomycota, Zygomycota and Chytridiomycota were significantly changed in different cropping years (p<0.05), The analysis at the genera level also showed that the ratios of 29 genera of bacteria and 19 genera of fungi were significantly changed in different cropping years (p<0.05). [Conclusion] With the extension of continuous cropping years,?ratios of various kinds of bacterial and fungi in ecosystem of strawberry rhizosphere soil will be changed significantly.