不同前茬对当归产量品质及根际微生物群落的调控机制探究

Angelica Sinensis (Oliv.) is a Chinese herbal medicin in Gansu province，The planting area and output all rank first in the country, but the problem of root diseases and quality decline has become increasingly prominent, which severely limits the development of industrialization of the Chinese angelica. Production practices and previous studies have shown that the disease and quality of roots of Angelica sinensis have a close relationship with the pods of the former crops; the intrinsic relationship between soil microorganisms and plant yield and quality in the rhizosphere is a research hotspot in recent years. Based on the principle of interaction between soil microorganisms and plant roots, this study conducted the cultivation of Chinese angelica root after cultivating the crops of different economic crops in the main producing area of Angelica and determined the growth and roots of the microorganisms and medicinal materials in the rhizosphere soil of Angelica sinensis by using the routine culture-free method (high-throughput sequencing). The disease occurrence rate, yield, quality, and other indicators, combined with soil physicochemical characteristics, analyzed the dynamics of microbial community structure in the rhizosphere soil during the planting process of Angelica sinensis. By comparing the differences in the microbial community structure between the diseased plants and healthy plants, and different previous cropping rhizospheres, we looked for relevant The microbiological factors revealed the relationship between the rhizophere microbial community and the yield and quality of medicinal materials in the rhizome of Angelica sinensis, and provided scientific basis for reducing the occurrence rate of root disease, improving the quality of Chinese angelica and exploring the transplanting of Chinese angelica.

当归为甘肃省道地中药材，种植面积及产量均居全国首位，但根部病害及品质下降问题日益突出，严重限制当归产业化发展。生产实践和前期研究表明当归根部病害及品质与前茬作物茬口具有密切的关系；根际土壤微生物与植物产量与品质内在关系是近年的研究热点。本文依据土壤微生物与植株根系相互作用原理，在当归主产区培育不同经济作物茬口后进行当归种植，通过定期采用免培养法（高通量测序法）测定当归根际土壤微生物以及药材生长、根部病害发生率、产量、品质等指标，结合土壤理化特性，分析当归种植过程中根际土壤微生物群落结构动态，通过比较发病植株与健康植株、不同前茬间当归根际微生物群落结构的差异，寻找相关微生物因子，揭示茬口对当归成药期根际微生物群落特征及药材产量和品质的关系，为降低当归根部病害发生率、提高当归品质及探寻当归移栽茬口提供科学依据。

当归为甘肃省道地中药材品种之一，但轮作倒茬困难问题日益突出，严重限制当归产业化发展。根际微生物群落是植物生长和物质交换的重要场所，是影响中药材品质和产量的重要因素。相关文献及本课题组前期研究均证实，不同前茬根际土壤微生物群落结构对当归品质存在着明显的差异。本研究从不同茬口对当归根际微生物及产量品质影响角度入手，通过定期测定土壤微生物和当归产量品质构成，旨在揭示不同前茬对当归成药期根际微生物及其与药材产量和质量的关系，研究结果归纳如下： .1、当归重茬后出苗率和保苗率减低，发病率升高，分别为57.71%、47.89%和49.04%。根干物质、阿魏酸、藁本内酯、浸出物和挥发油的含量有所提高，分别为30.52%、0.061%、1.275%、61%和1.34%，对应的产量最低。成药期茎叶形态性状的数值呈先升高后降低的趋势，不同茬口下当归的品质形成进程各有差异。重茬不适宜当归移栽。.2、不同前茬当归种植过程中放线菌门（Actinobacteriota）、变形杆菌（Proteobacteria）、绿弯菌门（Chloroflexi）、拟杆菌门（Bacteroidota）等为主要菌群。当归、党参、黄芪、蚕豆、油菜茬口根际土壤细菌群落Shannon指数在当归移栽生长周期能表现出“高-低-高”的变化趋势；马铃薯茬口Shannon指数随着移栽当归和当归的生长呈现出降低的趋势，而青稞茬口Shannon指数随着当归的生长呈现出升高的趋势。.4、各茬口当归成药中期及采收期子囊菌门（Ascomycota）、担子菌门（Basidiomycota）、黏膜真菌门（Mucoromycota）为主要细菌种群。当归、党参、黄芪、马铃薯、青稞、油菜前茬移栽当归后根际土壤真菌群落子囊菌门（Ascomycota）丰度呈现出“高-低-高”的趋势，蚕豆茬口移栽当归后根际土壤真菌群落子囊菌门（Ascomycota）丰度呈现出持续增加的趋势。黄芪茬口当归采收期等7个处理根际土壤真菌群落子囊菌门（Ascomycota）丰度均超过70%。综合分析，当归移栽的适宜茬口排序为青稞>党参>蚕豆>黄芪>马铃薯>油菜。.通过上述工作，较为系统地回答了不同前茬当归根际微生物群落变化以及对药材产量、品质形成的调控机制，结果可对揭示当归品质形成及优化种植茬口、合理轮作具有理论指导意义和实际的应用价值。.