三七免耕连作土壤微生态的演变特征与植物土传病害的关联性研究

Soil micro-ecological changes would affect the stability of the soil ecosystem, especially the relationship between changes in soil micro-ecology and plant soil-borne diseases, and it is the new and leading area in soil ecology, represent the developing direction of this science branch. For disset the relationship between the micro-ecological change and soil born disease in obstruct soil of no-tillage continuous cropping Sanqi, a soil position monitor region will be established in Sanqi garden for positioning monitoring studies in the whole growth period (3 years). Methods combined with molecular biology techniques will be used in this project, involving to analysis the change difference of soil microbial diversity, community structure and soil enzyme activity from the natural cultivation process in which it is intended to reveal the relevance between soil micro-ecological development characteristic and soil-borne diseases in no-till continuous cropping Sanqi, get the data of the soil microbial community structure, type of soil enzyme activity which is closely associated with Sanqi soil-borne diseases and their quantitative parameters, to explore the soil quality and safety evaluation of soil biology diagnostic parameters in Sanqi cultivate. Based on soil ecological theory, the relationship of the soil microbial community structure differences and the soil-borne diseases, interaction relationship of "soil microbes - soil enzyme - plants soil-borne diseases will analysis. The result will be useful for reconstruction the soil micro-ecological environment, solve the prevention and controlling of Sanqi soil-borne diseases in no-till continuous cropping obstacle in a scientific basis and new prevention strategies.

土壤微生态变化影响着土壤生态系统的稳定性，土壤微生态变化与植物土传病害的关系，是土壤生态学研究的新领域和发展方向。项目针对三七免耕连作土壤障碍的微生态变化与植物土传病害的关系问题，建立三七园地免耕连作土壤定位监测区，开展全生育期（3年）定位监测研究。结合分子生物技术分析方法，拟从自然栽培过程中土壤微生物多样性及其群落结构与土壤酶活性的变化差异方面，揭示出免耕连作土壤微生态的演变特征及其与三七土传病害的关联性，分析出与三七土传病害发生密切关联的土壤微生物群落结构、土壤酶活类型及其量变参数，探讨出三七栽培土壤质量与安全性评价的土壤生物学诊断参数。并基于土壤生态学理论，剖析土壤微生物群落结构差异与植物土传病害的关系问题，剖析免耕连作栽培下"土壤微生物－土壤酶－植物土传病害"间的互作关系。研究为免耕连作障碍土壤微生态重建及解决三七土传病害的生态防控，提供科学依据和新的预防策略。

土壤微生态变化与植物土传病害的关系，是土壤生态学研究的新领域和发展方向。项目针对三七免耕连作土壤障碍的微生态变化与植物土传病害的关系问题，建立三七园地免耕连作土壤定位监测区，从自然栽培过程中土壤微生物遗传多样性、特征微生物种群结构、土壤酶活性及土壤盐份浓度影响等方面，研究了土壤微生态的演变特征及其与三七土传病害的关联性，揭示出了三七免耕栽培土壤微生物与土壤酶活性的变化特征，分析出了三七土传病害的发生与土壤微生物和土壤酶活性的关联性，探讨了三七栽培土壤质量与安全性评价的土壤生物学诊断参数，剖析了土壤盐离子组份浓度对土壤微生物种群分布和土壤酶活性的互作影响及其与植物土传病害的关联性。结果显示：三七根腐发病率与各气候因素（地温、湿度、日照数/月）间均不存在统计学上的直线相关性（p＞0.05），但曲线回归分析达显著的相关性，说明气候因素特别是地温变化是通过影响土壤微生物种群变化，进一步影响三七根腐发病率的发生发展；三七根腐病害的发生及发病程度与根际土壤微生物类群比例的变化具有密切的关联性，根际土壤细菌与真菌比值(B/F)、细菌与放线菌比值(B/A)及好氧性细菌与厌氧性细菌的比值（Ae/An），可以作为评价三七土壤健康状况及病害防治测控的参考指标；土壤中Fusarium、Ralstonia、Stenotrophomonas 、Penicillium patulum和Trichoderma viride的丰度与三七土传病害的发生具有密切关联性，是导致三七连作障碍的主要微生物种群，发现Sphingobacterium multivorum、Pseudomonas chlororaphis 为疑似新种，是否为致病菌待研究；从健康土壤中纯化分离提取69株优势益生菌，其中新种6株；土壤中高浓度的盐分（EC值）抑制有益原核微生物种群的生长，特别是抑制Bacillus类群生长，同时抑制磷酸酶、脲酶及纤维素酶的活性；土壤中磷酸酶、多酚氧化酶及脲酶活性高低影响到三七的生长发育与发病程度，是导致三七连作障碍的主要酶活类型。本研究取得的相关成果，为三七连作障碍土壤微生态重建，提供科学依据和新的预防策略。