三七种植前后土壤营养、酶活性与微生物群落结构的变化研究

Study on Changes of Soil Nutrient, Enzyme Activity and Structure of Microbial Community before and after Cropping Panax notoginseng

【目的】明确三七连作对土壤养分、酶活性及微生物群落结构的影响,为克服三七连作障碍提供有效的策略。【方法】结合高通量测序技术,分析种植年限的延长对三七根际土壤真菌群落、细菌群落影响的相关性。【结果】随着种植年限的延长,土壤pH值、有机质、全钾、速效磷、速效钾含量上升,而全氮、全磷、碱解氮含量下降;土壤酶活性除碱性磷酸酶变化不大外,脲酶、蔗糖酶、多酚氧化酶均明显下降。高通量测序表明,三七种植前后土壤在科水平上检测分类出占比较高的真菌15类、细菌16类,其中,对照土壤中真菌主要以Hygrocybe为优势菌种,占比为55.17%;种植三七后土壤中真菌占比降至0.37%,Fusarium为优势菌种,占比为8.31%,其百分比含量增加32倍;种植三七后土壤中的细菌群落组成与种群密度变化明显,Pseudomonas、Streptomyces等生防细菌随着三七种植年限的延长呈下降趋势。【结论】随着三七种植年限的延长,土壤微生物的多样性总体呈上升趋势,土壤酶活性下降,土壤营养失调。

【Objective】The study was conducted to clarity the effects of Panax notoginseng continuous cropping on soil nutrient,enzyme activity and structure of microbial community and provide effective strategy for overcoming the obstacle to P.notoginseng continuous cropping.【Method】Combined with high-throughput sequencing,the influence of the extension of planting years on fungi and bacteria community of rhizosphere soil was analyzed.【Result】With the extension of plant years,the pH value and contents of total potassium,organic matter,available phosphorus and available potassium in soil were increased,while the contents of total nitrogen,total phosphorus,and alkali-hydrolytic nitrogen were decreased.Except for alkaline phosphatase,the activities of urease,sucrase and polyphenol oxidase in soil were decreased obviously.High-throughput sequencing showed that,15 fungi and 16 bacteria were detected and classified at the family level in soil before and after planting P.notoginseng.The Hygrocybe among the fungi from the soil(CK)before planting was the dominant strain,accounting for 55.17%,while the ratio was decreased to 0.37%after planting and the Fusarium was the dominant strain in the soil,accounting for 8.31%,which was 32 times higher than that before planting.The composition and population density of bacteria community in soil before and after planting P.notoginseng were obviously different,while the biocontrol bacteria like Pseudomonas and Streptomyces showed a decreasing trend with the extension of planting years.【Conclusion】Generally,the microbial diversity in soil showed an increasing trend with the extension of planting years.The soil enzyme activity descended and the soil nutrition lose bala nce.