棘托竹荪连作对根际土壤细菌的影响

Effects of Continuous Cropping of Phallus echinovolvatus on Rhizosphere Soil Bacteria

棘托竹荪连作导致棘托竹荪产量降低、质量下降.土壤细菌群落结构组成及变化能够反映生态系统的结构和功能,在生态系统物质养分循环中发挥着重要的作用.目前,棘托竹荪连作对土壤细菌群落结构组成及分布的影响尚不清楚.以连续三年棘托竹荪根际土壤为材料,探讨连续种植棘托竹荪对根际土壤细菌的影响,为调控棘托竹荪连作障碍提供理论依据.试验选择连续三年棘托竹荪出菇高峰期的土壤及对应的未种植棘托竹荪的样地,采用"S"形取样法采集土壤样品,对土壤进行理化性质及分子水平上对16SrRNA基因进行HiSeq2500测序研究,利用R语言和SPSS22.0等软件分析棘托竹荪连作对土壤细菌多样性及群落结构的影响.种植棘托竹荪后,与对照相比,土壤有机碳、全磷、碱解氮等的含量均增加,细菌种群数量和多样性均增加.连作三年后,种植棘托竹荪区域的土壤细菌种群与多样性降低,慢生根瘤菌属,Candidatus_Solibacter和Chthoniobacter的相对丰度随连作年限的增加而逐渐增加,Kaistobacter、假单胞菌属、黄杆菌属、金黄杆菌属等菌群相对丰度则逐年减小.在种植棘托竹荪区域,属水平上的菌落受土壤理化性质影响比较大,特别是pH、有机碳、全磷、碱解氮、速效磷和速效钾.随连作年限的延长,棘托竹荪根际土壤理化性质、细菌的群落多样性及结构发生显著变化.

Continuous cropping of Phallus echinovolvatus resulted in lower yield and decreased quality.The soil bacterial community structure can reflect the structure and function of ecosystem and play an im-portant role in the material and nutrient cycle of ecosystem.At present,the effect of continuous cropping of Phallus echinovolvatus on soil bacterial community remains unclear.The aim of this study was to explore the changes of soil bacteria diversity with Phallus echinovolvatus rhizosphere soil for three continuous cropping years,to provide theoretical basis for the control of Phallus echinovolvatus continuous cropping obstacles.In the experiment,the samples were collected from the soil growing Phallus echinovolvatus for three consecutive years and the areas where no Phallus echinovolvatus had developed,using“S”sampling method,on soil physicochemical property and molecular level sequence of 16S rRNA genes based HiSeq2500 sequencing,u-sing R and SPSS 22.0 software analysis soil bacterial diversity and community structure on the continuous cropping of Phallus echinovolvatus.Compared with the control,the content of soil organic carbon,total phos-phorus,alkali-hydrolysis nitrogen and so on increased.The number and diversity of bacterial population in-creased.After three years of continuous cropping,the bacterial diversities indexes were decreased in rhizo-sphere soil.Bradyrhizobium,Candidatus_Solibacter and Chthoniobacter were increased,but these were de-creased in Kaistobacter,Pseudomonas,Flavobacterium and Chryseobacterium.The soil physicochemical were correlated with genus level in rhizosphere soil.With the extension of three continuous cropping years,the bacterial of Phallus echinovolvatus rhizosphere soil will be changed significantly.