迁地保护是防止物种灭绝的有效措施。为了解在新栖息地兰科植物与昆虫之间的关系, 从而为兰科植物的保护提供借鉴, 作者对迁地栽培于深圳市全国兰科植物种质资源保护中心的本地种血叶兰(Ludisia discolor)和外来种银带虾脊兰(Calanthe argenteo-striata)的传粉系统和繁殖策略进行了观察和研究。血叶兰和银带虾脊兰都具有白色小花组成的花序, 且花有距。在开放栽培条件下, 菜粉蝶(Pieris rapae)是这两种兰科植物唯一有效的传粉者。菜粉蝶携带血叶兰和银带虾脊兰花粉块的部位分别是降落时平衡身体的左侧足部和取食花蜜的喙。两种兰科植物传粉效率较高, 花粉移走与沉降的比值分别为1.14:1和0.74:1。血叶兰的结实率在2007和2008两年间无显著差异, 且均高于银带虾脊兰。究其原因, 一方面是由于它为传粉者提供报酬; 另一方面是因为血叶兰的花期与菜粉蝶的盛发期相吻合, 有利于充分利用传粉者; 而银带虾脊兰的花期滞后于菜粉蝶的盛发期, 传粉者缺失使得部分花未能授粉。血叶兰和银带虾脊兰都是高度自交亲和的物种, 但不存在无融合生殖和自动自花授粉的现象; 自交和异交的繁殖成功率无显著差异。这两种兰科植物可能存在由传粉者导致的自交现象。血叶兰和银带虾脊兰在迁地栽培到兰科中心后生长良好, 每年花期都有自然结果的现象, 植株周围有新生幼苗的建立, 种群有逐渐扩大的趋势, 显示出迁地保护的可行性。可以预测若干年后, 这两个种在兰科中心具有建立稳定种群的可能性。

Ex-situ conservation is an effective measure to prevent extinction of species. In order to learn the plant-pollinator relationship in ex situ habitat and shed insights into the ex situ conservation, we studied the pollination system and reproductive strategy of two orchids Ludisia discolor from Wutong Mountains, Shenzhen and Calanthe argenteo-striata from Malipo, Yunnan in the Botanical Garden of the National Orchid Conservation Center (NOCC), Shenzhen, southeastern China in 2007 and 2008. Both species have inflorescences with many white flowers which have spur with a narrow entrance. The butterfly, Pieris rapae, was their solely legitimate pollinators. The pollinaria of L. discolor were carried on the legs of butterflies, while that of C. argenteo-striata on the proboscis. The pollination efficiency in both orchids was high, and the ratio of pollinaria removal to massulae deposition was 1.14:1 and 0.74:1 in L. discolor and C. argenteo-striata, respectively. In 2007 and 2008, fruit set of open pollination in L. discolor was higher than that in C. argenteo-striata, which could be explained by that the former provides rewards to its pollinators while the latter is deceptive, as well as by that the flowering period of L. discolor was synchronized with the abundance of butterflies, which favored the orchid to exploit its pollinators, whereas the flowering period of C. argenteo-striata was lagged behind the outbreak period of butterflies, which made the flowers suffer insufficient pollinator visitation. Both species were self-compatible but there were no spontaneous autogamy or apomixes. The fruit sets of cross-pollination and self-pollination showed no significant difference. Ludisia discolor and C. argenteo-striata grow well after being transplanted to NOCC, and new seedlings were found near parent plants, indicating the population tended to expand, and the ex situ conservation was feasible. It could be predicted that these two orchids have the potential to establish stable populations in NOCC in the future.