基于土壤元素谱和微生物地理学的川芎道地产区地理尺度研究

As the producing area of Chinese medicinal material is normally regarded as a warrant for its quality, genuine medicinal material has always been advocating for traditional Chinese medicine(TCM), while it is quite difficult to define the spatial scale of the area scientifically and precisely. The feature of geographical distribution of soil microbes can be considered as a profile of corresponding habitats and thus we put forward a hypothesis that the geographical distribution pattern of plant metabolism is a consequence of the interplay between plants and soil microbes, which could unveil the fundamental principle of "Yin Fang Chuan Xing" , a theory of TCM theory. The results of our precedent study shows that some endophytic fungi inhabiting in Chuanxiong varied according to the cultivating areas of their hosts. Therefore, we infer that part of unstable endophytic fungi in Chuanxiong are derived from soil, and the certain strains of endophytic microbes are promising to the characterization of the cultivating areas of Chuanxiong. Also some plant growth promoting rhizobacteria will certainly benefit the growth of the herb. This study intends to obtain the information of the element spectrum and the geographical distribution pattern of microbial community in soil and Chuanxiong, spanning the core to the periphery of the genuine origin areas of Chuanxiong, using the combination of gradient equidistant sampling method, and Cyclotron, NMR, XRF, MiSeq technology and platform. One ecological-mathematical model will then be conducted to the analysis the geographical scale of genuine cultivating areas of Chuanxiong based on the correlation of the soil element spectrum, the microbial community and the quality of Rhizoma Chuanxiong. This research would hopefully provide innovative ideas and methods for the explore of the geographical scale definition of genuine producing areas, and the study on genuine medicinal material and its regionalization.

中医药界历来崇尚道地药材，并用产地标识保证药材质量，然而“地”的空间尺度相当模糊。鉴于土壤微生物地理分布格局是环境特征的综合表征，我们提出“因方舛性”是土壤微生物与植物共同驱动植物代谢地理分布格局的假说。前期发现川芎存在随产地变化的不稳定内生真菌菌群，推测这些菌群来自土壤，植物吸收恰当配比的元素和感染相关微生物是其正常生长发育和形成优质药材的条件，利用与川芎相关的土壤微生物和元素谱信息能表征其产地特征。本研究拟采用等距结合梯度采样方法，利用Cyclotron、NMR、XRF、MiSeq技术平台，挖掘川芎核心道地产区至周边流域内土壤及川芎元素谱、土壤微生物及内生菌群落的地理分布格局信息，建立基于土壤元素谱-微生物群落-药材质量关联的生态数学模型，明晰川芎道地产地的地理尺度范围，建立道地产区地理尺度界定方法，为道地药材研究和生产区划提供新思路和新方法。

为揭示中药材川芎道地产区的“自然边界”，本研究主要利用XRF、ICP-MS、HPLC、Miseq平台高通量测序技术等全面分析了四川盆地内川芎传统种植区及扩展区土壤元素谱和土壤微生物群落结构的地理分异规律。研究发现，川芎传统种植区内土壤理化性质、土壤微生物群落结构和药材质量具有明显的稳定性或一致性，在向南/东扩增区内则呈现出受山脉及河流主导的地理分异特征。土壤中Ca、P、Ti、Sr、Cr、Cu、Co、Zr、As、La、Y、Pb、Ce、Cd、Th、HN、TN和pH等土壤因子是影响川芎质量形成的主导因子，可作为川芎栽培地适宜性评价的指标。土壤微生物存在与土壤元素类似的地理分异规律，但主要由非核心菌群的差异性引起。Rhizoctonia、Verticillium、Dactylonectria、Plectosphaerella、Neocosmospora、Boeremia等多种内生菌属与川芎指标性成分或挥发油成分显著相关。研究证实川芎道地产区存在客观的地理边界：即以四川省都江堰市石羊镇风堆村为中心，向东或南方向各延伸60km左右，该区域可满足优质川芎栽培的养分需求；向东延伸70km，向南90~130km左右，该区域内可满足优质川芎栽培的微生态条件需求。通过定点栽培试验及文献既往数据分析，验证评价了都江堰川芎传统种植区（道地产区边界内）、高相似边缘区域栽培地（道地产区边缘）和低相似区域栽培地（边界外）生产的川芎药材质量，发现川芎质量“边界”效应在很大程度上依附于“道地”土壤自然地理边界。由此，初步建立一种“基于药材质量形成相关的土壤主导因子评估和划分药材适宜生长区”的有效方法。本研究拓展了四川盆地川芎道地药材生产区的范围，并证实传统的道地产区具有一定可延伸性，但仍具有其自然地理边界。本研究对优质川芎药材生产具有重要的现实指导意义；为传统道地产区狭窄的优质药材生产提供了新的研究思路和方法。