濒危藏药红花绿绒蒿种子萌发的限制因子及解除方法研究

Meconopsis punicea, as an endangered and precious resource of Tibetan medicine and alpine ornamental plant, has important value of resource protection and development and application. However, the seeds of Meconopsis Punicea have the phenomenon of dormancy, and the mechanism and type of dormancy are not yet clear. This study attempts to (1) research into the response mechanism of the seed germination of Meconopsis punicea to habitat and elevation, so as to make clear how environmental factors (temperature, light, soil moisture and seed burial depth) affect seed germination and its influence mechanism; (2)conduct seed shape structure and embryo development observation, seed coat permeability test, seed embryo viability test, seed inhibiting substance identification of Meconopsis punicea, thus making clear the internal obstacles and dormancy types of seed germination of Meconopsis punicea, so that an effective germination method can be developed accordingly and to provide a theoretical basis and technical support for the protection of wild resources, domestication and cultivation, and deep resources development of Meconopsis punicea.

红花绿绒蒿(Meconopsis punicea Maxim．)作为濒危珍贵的藏药资源及高山观赏植物，具有重要的资源保护及开发应用价值，但红花绿绒蒿种子具有休眠现象，且休眠机理及休眠类型尚未明确。本研究试图通过（1）研究红花绿绒蒿种子萌发对生境、海拔的响应机制，明确环境因子（温度、光照、土壤水分和种子埋藏深度）对种子萌发的影响及其作用机理；（2）对红花绿绒蒿种子进行形态结构及种胚发育程度观察，种皮透性测验，胚活力测定，种子抑制物质的毒性测验及鉴定等方面的研究，明确红花绿绒蒿种子萌发的内部障碍及休眠类型，并制定出与之对应的高效催芽方法，为红花绿绒蒿野生资源保护，人工驯化栽培及深层次的资源开发提供理论依据及技术支持。

红花绿绒蒿作为珍稀濒危的藏药资源及高山观赏植物，因过度采集、生境退化及种子休眠等因素的影响，野生资源面临着枯竭的危险。为了保护这种稀缺的藏药资源，本研究进行了红花绿绒蒿资源调查，种子萌发特性，种子质量与产地环境因子的相关性研究。结果显示：（1）红花绿绒蒿集中分布于四川西北部、西藏东北部、青海东南部和甘肃西南部海拔3500～4000m的山坡草地及高山灌丛，野生资源蕴藏量仅有1百余吨，野生抚育及人工驯化栽培迫在眉睫。（2）红花绿绒蒿种子具有形态生理休眠(MPD)特性，变温层积和野外适生区自然层积是解除红花绿绒蒿种子休眠的有效方法，恒温10℃、纸床、全黑暗条件是红花绿绒蒿种子发芽的最适条件。呼吸代谢由EMP途径/TCA循环向PPP途径转变是打破红花绿绒蒿种子休眠的关键，KT/ABA、GA3/ABA、IAA/ABA、(GA3+IAA)/ABA比值变化是打破红花绿绒蒿种子休眠的直接原因。（3）种子千粒重与产地海拔呈显著正相关关系（P＜0.05），与产地经度、纬度均呈显著负相关关系（P＜0.05），种子长与经度呈显著负相关关系（P＜0.05），种子长、种子宽、千粒重与产地土壤因子无显著相关关系（P＞0.05）。以上研究成果对保护红花绿绒蒿野生资源、人工驯化栽培及深层次的资源开发均具有重要意义。