Am J Bot. 1998 Apr;85(4):508.
Nectar reabsorption in flowering plants seems to be a rare phenomenon and to our knowledge it has not been reported previously in the Orchidaceae. In this study we present data that show statistically significant differences in nectar sugar concentrations before and after pollination. Virgin flowers of the African epiphytic orchid Aerangis verdickii showed mean sugar concentrations in the nectar of 14.4 and of 18.3% in 1994 and 1995, respectively (sucrose mass by mass equivalent). Sugar concentration in nectar from naturally pollinated flowers had a mean of 3.2 and of 8.7% for the same period. In an experiment in the wild 60 flowers were protected against nectar theft by the ants. Half of those flowers were hand-pollinated. Control (virgin) flowers had nectar with a mean value of 13.8%, while flowers measured 48 h after pollination had a mean sugar concentration of 4.3%. The mean volume of nectar based on measurements of 23 virgin flowers from nine different plants was 19 uL. We estimated an average energy value for the nectar produced of 684 J per plant per season. At the study site, over 60% of the unmanipulated flowers were robbed of all their nectar by arboreal ants, Polyrachis spp. (Formicinae). The adaptive significance of nectar reabsorption for A. verdickii is probably a function of the environmental stresses to which it has been exposed and the relative costs of nectar production.
在开花植物中，蜜液再吸收似乎是一种罕见的现象，据我们所知，在兰科植物中尚未有过报道。在这项研究中，我们提供的数据表明授粉前后蜜液中糖浓度存在显著差异。非洲附生兰花 Aerangis verdickii 的处女花在 1994 年和 1995 年的蜜液中分别显示出 14.4%和 18.3%的平均糖浓度（以蔗糖质量当量计）。自然授粉花朵的蜜液中糖浓度在同期分别为 3.2%和 8.7%。在野外的一项实验中，有 60 朵花受到蚂蚁的保护，防止它们窃取花蜜。其中一半花朵被人工授粉。对照（处女）花的蜜液平均含糖量为 13.8%，而授粉 48 小时后的花朵平均含糖量为 4.3%。根据对来自九株不同植物的 23 朵处女花的测量，花蜜的平均体积为 19 μL。我们估计，每株植物每季节生产的花蜜平均能量值为 684 J。在研究地点，超过 60%的未受人为干预的花朵的花蜜被树栖蚂蚁（Formicinae 的 Polyrachis spp.）全部窃取。蜜液再吸收对 A. verdickii 的适应意义可能是其暴露于环境压力和花蜜生产相对成本的函数。
