三七连作土壤障碍因子及其生物消减机制研究

Soil cropping problems under continuous cropping condition have already been an important factor to restrict the sustainable development of tradition Chinese medicine. To solve the soil continuous cropping problem with biological modifications, we pretend to study how the soil continuous cropping problem occurs, with the aspect of interaction between soil activity factors and soil characters, on the Sanqi field in situ where we’ve selected as long-term monitoring place under natural cropping conditions. From the aspect of keeping the soil ecological system balance, we’re going to reducing the influence of soil continuous cropping with application of beneficial microorganisms and biological substrate to regulate the microbial community with the parameters analysis of health plant rhizosphere. The program applied will reveal the mechanisms of interaction between soil activity factors and soil characters. With the analysis of the parameters of soil activity factors and soil characters in the health plant rhizosphere, we could know how to construct healthy microbial community to reduce the influence of continuous cropping. Study the interaction among plant soil-borne disease, soil activity factors and soil characters under the no-tillage but continuous cropping system with the theory of soil ecological biology will help us to find new ways to reduce the influence of pharmaceutical plant continuous cropping to make the Sanqi cropping sustainable come true.

连作土壤障碍已成为制约我国中药材发展的重要因素。项目针对三七连作土壤障碍因子及其生物消减机制问题，在三七原产地建立定位监测区，在自然栽培环境下，从土壤活性因素与土壤理化因子演变及其互作影响方面，研究三七连作土壤障碍因子的发生机制；从平衡土壤生态系统方面，采取植物抗病菌与优势益菌群复合，生物基质消减与土壤微生态种群调节相结合的方法，试验研究抑制或消减三七连作障碍因子的机制和方法。项目实施，分析出障碍三七种植的土壤活性因素与土壤理化因素影响及其量变参数，获得健康土壤微生态构建的技术参数，探索出三七连作障碍因子生物消减的机制和方法。基于土壤生态学理论，剖析免耕连作栽培“植物土传病害－土壤活性因素－土壤理化因子”间的互作关系。本研究为预防药用植物连作障碍，实现三七的生态种植，提供科学依据和新的预防策略。

土壤连作障碍已成为制约我国中药材产量和品质提升的重要瓶颈，项目针对三七连作土壤障碍因子及其生物消减机制问题，在三七原产地建立多点定位试验监测区，从土壤微生物多样性组成、土壤酶活性因素、土壤理化因子及其互作影响方面，研究三七连作土壤障碍因子的发生机制；从土壤微生态系统修复方面，研究抑制或消减三七连作障碍因子的机制和方法。重要结果：（1）系统地阐明了三七种植土壤主要障碍因素及其发生机制，系统解析了三七土传病害的致病机理。阐明了土壤微生物种群动态变化及健康与病害土壤微生物区系在门类、属间、种间差异与土传根腐病害的关联性，明确了土壤真菌种群变化是导致青枯型和黄腐型根腐病主要原因；确定了土壤主要障碍因素分别为：Fusarium oxysporum、Cladosporium cladosporioides、Ralstonia、Stenotrophomonas 、Penicillium patulum和Trichoderma viride等，土壤磷酸酶、多酚氧化酶、脲酶，土壤pH值、硝酸盐、硫酸盐、碳酸盐等离子浓度；（2）明确了抑制三七病原菌的高效新生防菌和新活性化合物，探索出了三七连作障碍因子生物消减的机制和方法。通过系列试验与应用验证，获得抑制三七病原菌的真菌、细菌和放线菌126株，其中生防指数67.6%-85.3%高效活性菌株26株，从高效活性菌株中分离鉴定生防活性成分130余个，其中高活性成分62个、新化合物20余个，对三七病原菌最小抑制浓度（MICs）可达16μg/mL或更低；（3）优化集成了三七主要种植土壤类型区连作障碍消减的技术体系，并推广应用。.　项目研究成果，对构建三七种植健康土壤体系及实现三七生态种植等方面具有重要的指导意义，也为研究南方酸性红壤区其它作物土壤障碍因素消减机制方面，提供了全新的方法途径和指导作用。