供水延迟和氮添加对独蒜兰资源分配及生长繁殖的影响

The genus Pleione D. Don (Orchidaceae) holds world-famous ornamental plants and important Chinese medicinal herbs. However, the natural populations of many species continue to be collected and under threat, while the techniques of artificial cultivation are not yet known well for the lack of knowledge on how Pleiones adapt to environmental factors. Most Pleione species have an epiphytic habitat, in which they frequently encountered water stress and nutrients shortage due to the detachment of the epiphytic habitat to terrestrial soil. The present project aims to investigate: 1) the conversion and allocation of the dry matter in the pseudobulb and the differential expression of drought-related genes under different degrees of delayed water supply; 2) the interactive effects of water stress and nitrogen deposition on the current year’s growth and reproduction; 3) the effects of fruit bearing, delayed water supply and nitrogen addition on the future growth and reproduction of Pleione plants. By the combining of morphological, physiological and molecular data, we hope the findings will bring a better understanding of the water and nitrogen needs of Pleione plants, and we also hope the accomplishment of this project will shed light on the protection and sustainable use of Pleione species, as well as on how epiphytic orchids response to global change.

兰科独蒜兰属（Pleione D. Don）植物是世界著名的观赏花卉和重要的传统中药。当前其人工栽培技术尚不成熟，许多种类自然种群遭到严重破坏，清楚认识其生物学特性及环境适应性、促成人工栽培将有助于更好保护和利用这类珍贵的资源。该属多数种类都有附生习性，其生境缺少缓冲基质，水分胁迫和养分匮乏是影响该类植物种群动态的关键环境因子。本项目拟以独蒜兰为对象，开展三方面的研究：1）采用干旱控制实验，揭示不同供水制度下独蒜兰假鳞茎内物质的转化和分配、耐旱基因的差异性表达；2）结合氮添加实验，认识干旱和氮沉降的交互作用对独蒜兰当年生长、繁殖的影响；3）通过人工授粉研究植株当年的结实行为、干旱和氮添加等因子对未来生长和繁殖的影响，以期从形态、生理和分子三个层面认识独蒜兰属植物的水分和养分需求，为该属植物资源的保护和利用提供科学依据，也为附生植物响应全球变化提供新的认知。

兰科独蒜兰属植物是世界著名的观赏花卉和重要的传统中药。清楚认识其生物学特性及环境适应性、促成人工栽培将有助于更好保护和利用这类珍贵的资源。本研究以艳花独蒜兰为材料，利用同位素标记、生理生化物质测定和组学技术等方法研究了假鳞茎在氮营养分配和干旱胁迫适应等方面的作用。研究发现独蒜兰假鳞茎内部储存的氮元素对新生器官，特别是果实的发育起了不可替代的作用。假鳞茎的代谢物积极响应外界水分条件变化，在植株应对干旱胁迫过程中发挥了重要的作用。不同年龄假鳞茎对外界水分变化的差异化响应还暗示了不同年龄假鳞茎在干旱胁迫中扮演了不同角色。假鳞茎的存在有利于增强独蒜兰对贫瘠和缺水的附生生境的适应。该研究有助于了解附生兰科植物对其生境的适应机制，也能为相关珍稀濒危类群植物的保护和可持续利用提供借鉴。