不同类型土壤种植辣椒前后微生物多样性比较

Microbial Diversity Change in Different Soil Types After Cultivating Pepper

旨在通过研究种植辣椒后的不同类型土壤根际微生物的群落结构变化特征,探索适合辣椒种植的微生物群落结构与土壤类型。以辣椒自交系SJ11-3为材料,利用Illumina MiSeq 2500测序平台对其种植前后不同类型土壤(包括潮土、稻田土和黄棕土)根际微生物进行测序和生物信息学分析,研究土壤细菌16S r RNA基因V3+V4区域和真菌ITS1区域的丰富度、多样性及微生物群落结构。结果表明,种植前土壤中共获得2253个细菌分类操作单元(OTU)和775个真菌OTU,种植后土壤中共获得2353个细菌OTU和877个真菌OTU。辣椒种植会使不同类型土壤中细菌和真菌的OTU数量有所上升,且潮土中特有的OTU在种植辣椒前后均明显高于稻田土和黄棕土。同时研究发现,辣椒种植后Rhodanobacter、Gemmatimonas、Bradyrhizobium、Sphingomonas等细菌和Fusarium、Penicillium等真菌在不同类型土壤中相对丰度均显著升高。另外群落物种丰富度指数(ACE和Chao1指数)和群落多样性指数(Shannon和Simpson指数)分析发现,种植辣椒会使潮土、稻田土和黄棕土中真菌Shannon指数显著升高,而Simpson指数显著降低,物种多样性显著上升;细菌多样性则无显著变化。种植辣椒对潮土、稻田土和黄棕土中微生物多样性的变化均会产生重要影响,改变土壤微生物的丰富度及OTU类型。潮土在种植辣椒后微生物群落结构较为健康,未发现有大量病原菌富集,但稻田土和黄棕土则更容易造成病原菌的富集,因此推荐潮土为辣椒种植的适宜土壤。

To explore the microbial community structure and soil type suitable for pepper cultivation through the changes of the community structure of different soil rhizosphere microbes after pepper planting,we used the pepper(Capsicum annuum)SJ11-3,an inbreed line,as the material,and conducted the high throughput RNA-seq sequencing via Illumina MiSeq 2500 sequencing platform on the rhizosphere microorganisms from three different types of soil(fluvo-aquic soil,paddy soil and yellow-brown soil)after cultivating pepper with uncultivated soil as control.Using bioinformatics analyses,we evaluated the abundance indexes and the diversity indexes from the V3+V4 region of 16 S rRNA gene of soil bacteria and the ITS1 region of soil fungi as well as the soil microbial community structure.The results showed that a total of 2253 bacterial Operational Taxonomic Units(OTUs)and a total of 775 fungal OTUs were obtained in control while a total of 2353 bacterial OTUs and a total of 877 fungal OTUs were obtained after planting pepper.Planting pepper caused the increase of bacterial OTUs and fungal OTUs in the three different types of soil and the number of OTUs unique to fluvoaquic soil was significantly higher than those unique to paddy soil and yellow-brown soil before and aftercultivating pepper.In addition,we also found that the relative abundances of bacterial genus,including Rhodanobacter,Gemmatimonas,Bradyrhizobium and Sphingomonas etc.,and the fungal genus,including Fusarium and Penicillium etc.,were significantly increased in three types of cultivated pepper soil.Meanwhile,the analyses of the microbial community species abundance indexes(ACE and Chao1 indexes)and themicrobial community species diversity indexes(Shannon and Simpson index)indicated that planting peppercaused the significant increase of the fungal Shannon index but significant decrease of Simpson index in fluvo-aquic soil,paddy soil and yellow-brown soil.However,the bacterial community diversity indexes did notchange significantly.The results indicated that cultivating pepper could cause significant influence on thechanges of the microbial community diversity,the relative abundances and type of OUT in soil,and enhancethe growth and reproduction of bacterial genus and fungal genus in soil.Among the three types of soil,afterplanting pepper,the microbial community structure in fluvo-aquic soil was healthier and no large enrichmentof pathogenic bacteria was observed.However,in paddy soil and yellow-brown soil,the enrichment ofpathogenic bacteria easily occurred.Thus,we recommend fluvo-aquic soil as the suitable type for cultivatingpepper.