乌、红天麻与蜜环菌生物种的共生选择性及其环境调节研究

Gstrodia elata BL. is a famed traditional medicine of China. It is reported that Gstrodia elata BL. finishes its lifecycle through symbiosis with Armillaria mellea, so its yield and quality is influenced by A. mellea vastly. In fact, A. mellea in China is comprised of 15 Armillaria biological species (ABS), also there are 6 G. elata subspecies in China，so the symbiosis relationships among them are compexed than ever reported. Studies abroad had proved that there is selectivity between Gstrodia elata BL. and biological species of A. mellea. However, the acurate symbiosis slectivity among G. elata BL. subspecies and ABS is ambiguous, which brought enormous risks to Gstrodia elata BL. cultivation. So determination which ABS can build perfect symbiosis with G. elata subspecies is of important value in field cultivating of G. elata BL. .In this application, we plan to conduct a series of in-situ experiments in Shennongjia Area to monitor the symbiotic selectivity among ABS and G. elata subspecies . We will select two subspecies of G. elata BL.(G. elata BL. f. glauca S. Chow and G. elata BL. f. elata, which are regarded as the subspecies of important economic value) and 15 ABS of China as material, and construct field experimental sites at 400, 800, 1200 and 1700 m altitude, respectively. One HOBO Mini weather station will be set in each experiment site , through which environment changes along altitude can be monitored, and BTC Mini-rhizotron Root Ecology Mornitoring System will be buried in each cultivating plot, so the symbiosis dynamics of each group of G. elata subspecies ×ABS can be monitored. Then we can analyze the selectivity among subspecies of G. elata and ABS, and the effects of environmental factors on this selectivity. In addition, we will measuring gastrodin content of each G. elata subspecies ×ABS, so the effects of ABS and environmental factors on medical quality of G. elata BL. can be analyzed. ..To understand the nature of symbiotic selectivity and environmental factors effects on this selectivity, symbiont of G. elata and ABS will be cultivated at 8℃、15℃、20℃、25℃、30℃ and 35℃, then the inhibition effect of anti-fungal protein in G. elata on each ABS, temperature effects on virulence of each ABS and digestion ability of subspecies of G. elata will be tested and analyzed..Our aims are projected on the following questions: ①Which ABS can build an balanced symbiosis with the aim subspecies of G. elata? ②How does the environmental factors, especially temperature, regulate this symbiotic selectivity? ③How do ABS and environmental factors affect the yield and medical quality of G. elata cultivated in field ? ④What's the mechanism of temperature affecting the symbiosis among G. elata BL. subspecies and ABS ? Answering these questions will not only be helpful to a deeper understanding of the relationship among G. elata BL. and Armillaria mellea, but also be beneficial to the perfect cultivation of G. elata BL. in China.

天麻是我国的名贵中药材，通过与蜜环菌共生获得营养，其产量和品质与蜜环菌种类密切相关。我国有6个天麻变型和15个蜜环菌生物种，但二者间共生选择性及其环境调节尚不明确，为天麻栽培用蜜环菌资源的利用、选育和天麻栽培带来极大困扰。本课题以神农架地区为研究基地，以最具经济价值的乌、红天麻和我国15个蜜环菌生物种为对象，在神农架不同海拔地区建立试验场，构建环境梯度系列并种植“天麻变型×蜜环菌生物种”组合，采用微根管系统观测蜜环菌索发育及天麻变型与蜜环菌生物种的共生动态，揭示二者间的选择性及其环境调控特征，明确蜜环菌生物种和环境对乌、红天麻药用功能性状的影响；同时，在室内研究温度对蜜环菌侵染性和乌、红天麻防卫系统的影响，揭示温度调控二者共生关系的机制。本研究在生物学领域和天麻栽培学领域均属首次，对于深化天麻和蜜环菌生物学关系的认识具有科学价值，能为天麻伴栽用蜜环菌种选育提供理论支撑，具有重大应用前景。

天麻是我国的名贵中药材。天麻属植物通过与蜜环菌共生获得营养，其产量和品质与蜜环菌种类密切相关。我国有多个天麻变型和多个蜜环菌生物种，但二者间是否存在共生选择性、是否存在环境调节尚不明确，为天麻栽培用蜜环菌资源的利用、优良菌株的选育和天麻栽培带来极大困扰。本课题以鄂西地区为主，系统调查了该地区蜜环菌的分布及其遗传多样性水平，并对我国主要天麻产区的栽培用蜜环菌株进行了分子鉴定。同时，以最具经济价值的乌、红天麻和我国主要的蜜环菌生物种为对象，在湖北省宜昌市五峰县、夷陵区的不同海拔地区建立试验场，构建环境梯度系列以种植“天麻变型×蜜环菌生物种”组合，观测天麻变型与蜜环菌生物种的共生动态，揭示二者间的选择性及其环境调控特征，明确蜜环菌生物种和环境对乌、红天麻药用功能性状的影响；同时，在室内研究了温度对蜜环菌侵染性和乌、红天麻防卫系统的影响，揭示温度调控二者共生关系的机制。结果表明，（1）在鄂西地区分布有8个蜜环菌生物种，发现了CBS N、CBS O在湖北省的新分布， 而CBS L为优势的蜜环菌分类单元；（2）目前栽培用的蜜环菌株以CBS B为主，占样本总数的84.21%，因此其遗传背景较为单一，可能是全国范围的无性引种所致；（3）天麻变型对蜜环菌生物种具有明显的选择性，其中以CBS B和CBS D亲和性较差，CBS F和CBS M亲和性较高；在850~1900 m 海拔范围内，海拔对红天麻与蜜环菌生物种的共生关系没有影响，对乌红杂交天麻与蜜环菌生物种的共生关系具有显著影响。尤其重要的是，蜜环菌生物种类群对红天麻的药用成分含量存在显著影响，以CBS F为首选蜜环菌生物种，除CBS D不能共生外，CBS B是最差的栽培用蜜环菌种质资源；对于乌红杂交天麻，CBS F伴栽样品的有效成分总量较高，CBS B最低。（4）温度变化对天麻-蜜环菌的共生关系具有显著的调节作用，因为蜜环菌能随温度升高提升其侵染力，而天麻则降低了其消化蜜环菌的能力，从而破坏了蜜环菌和天麻的共生关系。本研究在生物学领域和天麻栽培学领域均属首次，对于深化天麻和蜜环菌生物学关系的认识具有科学价值，能为天麻伴栽用蜜环菌种选育提供理论支撑，具有重要的应用前景。