杓兰属植物的开花和结实动态

Flowering and fruit set dynamics in Cypripedium

作为被子植物中最进化的类群,兰科植物的开花和结实动态对制定其保护策略具有重要意义。利用20032007年的数据,对分布于四川黄龙寺自然保护区的5种杓兰的种群开花和结实动态进行了分析。结果表明所研究的所有杓兰种类均是自交亲和物种,但在自然条件下都必须依赖传粉媒介才能成功结实。尽管不同种类的杓兰植物具有不同的开花时间,但统计分析表明杓兰属植物的开花早晚与其结实率之间相关性并不显著,这可能因为不同的杓兰具有不同的传粉系统而导致的。而杓兰属植物的花期长短与结实率之间却呈显著的负相关,这可能是与杓兰属植物具有典型的欺骗性传粉系统相关的。另外,除绿花杓兰外,其他4种杓兰2003年的结实率明显高于20042007年间的结实率。而2003年一个突出的事件即是发生了SARS导致游客人数显著减少,暗示了人为活动对杓兰属植物成功结实具有比较大的影响。

The dynamics of flowering and fruit set of five Cypripedium species was evaluated during 2003 2007 in Huanglong Nature Reserve,Sichuan.Examination of the breeding system suggests that flowers of Cypripedium are selfcompatible but need pollen vectors for successful reproduction.No signifiacnt relations were detected between flowering time and fruit set in five Cypripedium species,which may be caused by that differnet Cypripedium species having different pollination systems.However,fruit sets depend negatively on the flowering duration in population level,which is relative to the learning ability of its pollinators in Cypripedium with typical deceptive pollination systems.In addition,fruit sets in 2004 2007 were significantly higher than those in 2003 in all Cypripedium species except C.henryi,thus pointing to the possibility that human disturbance had an effect on the level of fruit set because there were few visitors in 2003 due to SARS.