广西极小种群野生植物代表类群——穴居性石山苣苔属植物保育生物学和回归引种研究

Two typical cave-dwelling species of Petrocodon, Pet. jingxiensis and Pet. lui, belong to Plant Species with Extremely Small Populations (PSESP). They are in critically endangered due to their extremely limited distribution and small population. The genetic diversities, Ex situ (in Guilin Botanical Garden and similar cave habitats nearby GBG) and Near situ conservation (nearby type location) of two endemic Petrocodon species will be studied to realize ecological reintroduction. At the same time, diversities and structures, mating systems and paternity analysis of two species populations, genetic drift in Ex situ conservation populations of two species will be further researched by nuclear SSR markers. We will achieve the data of genetic variation and differentiation of two species, which are endemic to limestone caves, in this genus, so that the genetic characteristics of two species populations will be explored; the best strategy of sampling will be expounded for Ex situ conservation. Based on the researches of plant nutrition and cave-dwelling ecological communities design in Ex situ conservation situation for ecological reintroduction, we select similar cave habitats to realize. At the same time we will build artificial rejuvenated population and use nuclear SSR markers to monitor the genetic drifts of the Ex situ conservation populations. The result will reveal the genetic diversity and endangered mechanism of two cave-dwelling Petrocodon species, and provide a scientific basis for rational and effective protection germplasm resources of theirs.。

拟对两种极小种群的穴居性石山苣苔属植物--靖西石山苣苔和陆氏石山苣苔进行遗传多样性、迁地（桂林植物园内与选择植物园附近相似的山洞生境）与近地回归引种研究。采用SSR分子标记对两个洞穴局限分布的种之种群遗传多样性、遗传结构、交配系统和亲本、迁地保护群体的遗传漂变进行分析，将首次获得该属中特化于洞穴中的物种的种群分子遗传变异和遗传分化数据，并揭示其种群遗传特征；采用SSR分子标记研究两个种迁地保护的最佳取样策略；并在迁地状态下的植物营养因子研究基础上，进行洞穴植物生态回归的物种群落设计，并选择具有生态相似性的洞穴对其进行迁地和近地适应性生态回归；同时也在桂林植物园中，构建人工复壮种群，并利用SSR分子标记技术开展迁地保护种群的遗传漂变监控研究。上述研究将最终揭示两个极度濒危的极小种群野生洞穴植物种群遗传多样性及其濒危机制，为合理有效地保护以其为代表的穴居性极小种群野生植物种质提供有益的参考。

我国华南至西南广袤的喀斯特岩溶山地是世界上广义石山苣苔属Petrocodon植物主要分布区，很多种类生存现状堪忧，尤其是以穴居性的石山苣苔属更甚。以近年来才发现的、生存现状均被评估为极危（CR）的靖西石山苣苔Pet. jingxiensis和陆氏石山苣苔Pet. lui为例，从原生环境生态因子、种群生态位和种子萌发响应等方面初步研究了目标物种与环境之间、目标物种与伴生物种之间以及种内繁殖的相互关系，旨在揭示两种岩溶穴居性石山苣苔属植物的生境适应性、濒危现状及可能的致濒原因，为该类极小种群野生植物的科学有效保护和复壮提供理论依据。同时从遗传多样性等方面着手，以SSR 分子标记技术测定供试物种的交配系统，探讨两个穴居性代表物种在繁殖过程中的致濒因素。研究结果将有助于深刻认识其致濒原因，为穴居性石山苣苔属植保护和物种恢复提供科学理论依据。