来自厄瓜多尔南部山地森林的47种龙胆目植物的花蜜糖分组成和体积。
Nectar sugar composition and volumes of 47 species of Gentianales from a southern Ecuadorian montane forest.
作者信息
Wolff Doris
机构信息
Department of Plant Systematics, University of Bayreuth, 95440 Bayreuth, Germany.
出版信息
Ann Bot. 2006 May;97(5):767-77. doi: 10.1093/aob/mcl033. Epub 2006 Feb 22.
BACKGROUND AND AIMS
This study investigates 47 taxonomically related species (Gentianales), all native to a tropical montane forest in southern Ecuador, in terms of nectar chemistry and nectar volumes in relation to pollination biology.
METHODS
Nectar volumes of covered (24-h production) and uncovered (standing crop) flowers were measured in the natural habitat. Sucrose, fructose and glucose were quantified in the nectar using high performance liquid chromatography. Flower visitors were observed.
KEY RESULTS
Nectar sugar concentration did not differ significantly among the pollination syndromes. Regarding sugar composition, the only significant differences were found in chiropterophilous and myiophilous flowers, which had a significantly lower sugar ratio than sphingophilous flowers. A separation of chiropterophilous and myiophilous flowers from the other pollination syndromes is further substantiated by non-linear multidimensional scaling using the chord-normalized expected species shared index of dissimilarity based on nectar sugar compositions. The matrix test revealed no correlation of observed floral visitors to nectar concentrations; however, a weak significant correlation was found between floral visitors and nectar sugar compositions. The nectar volumes of covered and uncovered flowers are related to, and differ significantly among, pollination syndromes. Matrix tests revealed correlation between floral visitors and nectar volume of covered flowers and, to a lesser extent, of uncovered flowers.
CONCLUSIONS
Sucrose is the predominant floral nectar sugar in the order Gentianales, suggesting that nectar sugar composition is a conservative characteristic. However, some degree of an adaptive convergence of floral nectar compositions to principal pollinator type within the constraints set by phylogenetic history is likely. The driving force to visitation appears to be the volume of nectar the visitor can expect to consume.
背景与目的
本研究调查了47种分类学上相关的物种（龙胆目），这些物种均原产于厄瓜多尔南部的热带山地森林，研究内容包括花蜜化学以及与传粉生物学相关的花蜜量。
方法
在自然栖息地测量了有覆盖物（24小时分泌量）和无覆盖物（现存花蜜量）花朵的花蜜量。使用高效液相色谱法定量花蜜中的蔗糖、果糖和葡萄糖。观察访花者。
主要结果
传粉综合征之间的花蜜糖浓度没有显著差异。在糖成分方面，仅在蝙蝠传粉和蝇类传粉的花朵中发现了显著差异，它们的糖比例明显低于天蛾传粉的花朵。基于花蜜糖成分，使用弦归一化预期物种共享差异指数的非线性多维标度法进一步证实了蝙蝠传粉和蝇类传粉的花朵与其他传粉综合征的分离。矩阵检验显示观察到的访花者与花蜜浓度之间没有相关性；然而，在访花者与花蜜糖成分之间发现了微弱的显著相关性。有覆盖物和无覆盖物花朵的花蜜量与传粉综合征相关，且在传粉综合征之间存在显著差异。矩阵检验显示访花者与有覆盖物花朵的花蜜量之间存在相关性，与无覆盖物花朵的花蜜量也有一定程度的相关性。
结论
蔗糖是龙胆目中花蜜的主要糖类，这表明花蜜糖成分是一个保守特征。然而，在系统发育历史所设定的限制范围内，花蜜成分可能会在一定程度上向主要传粉者类型发生适应性趋同。访花的驱动力似乎是访花者预期能消耗的花蜜量。
Zotero 插件