Nectar secretion and nectaries in basal angiosperms, magnoliids and non-core eudicots and a comparison with core eudicots
Nectar secretion and nectaries in basal angiosperms, magnoliids and non-core eudicots and a comparison with core eudicots
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DOI：
10.1127/1869-6155/2014/0131-0075
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发表时间：
2014-01-01
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影响因子：
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通讯作者：
Erbar, Claudia
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文献类型：
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作者：
Erbar, Claudia
这项比较研究结合了原始结果与文献综述，总结了我们目前的知识，在被子植物花蜜腺。重点主要是在科（和属）水平上评价的基底被子植物（ANITA或ANA级和木兰科）。在大多数目中，至少有一个属是首次被研究或被重新研究。第二部分与核心真双子叶植物的成员进行了比较（在目的水平上）。在基部被子植物中，在一些科和属中，花蜜被提供，尽管不是大量的，并且除了花粉作为奖励。蜜腺部位是未分化的花被、退化雄蕊（“花瓣”）、雄蕊和心皮。雄蕊蜜腺占优势。花托花盘蜜腺不存在。关于组织学，可以发现所有类型的分化上皮蜜腺、叶肉蜜腺和毛状蜜腺，上皮蜜腺是最常见的蜜腺分泌类型。蜜腺在基群中的多样性结构、罕见的出现和分散的分布表明了趋同进化。花粉花分泌蜜腺的选择优势是什么？有人提出（Nepi等人，2009年），花蜜供应是对已经习惯于含糖分泌物（如裸子植物的授粉滴）的昆虫的一种适应。另一种（或补充）的方法，结果从观察花蜜生产主要限于雌性阶段的原雌蕊花。可以得出结论（参见Erbar & Leins 2013），花蜜确保了花在非花粉呈现阶段的吸引力。此外，在寻找稀疏花蜜的过程中，昆虫可能会接触到每个柱头，从而补偿了与雌雄同体雌蕊群相比，全生雌蕊群的经济劣势。
This comparative study combines original results with a review of the literature summarizing our present knowledge as regards nectaries in angiosperm flowers. The focus is mainly on the basal angiosperms (ANITA or ANA grade and magnoliids) which are evaluated at the family (and genus) level. In most orders at least one genus has been studied for the first time or was re-investigated. In the second part a comparison is made with members of the core eudicots (at the order level).In basal angiosperms, in a number of families and genera nectar is offered, though not in great amounts and in addition to pollen as a reward. Nectary sites are the undifferentiated perianth, staminodes ("petals"), stamens, and carpels. Staminodial nectaries dominate. Receptacular disc nectaries are absent. As regards histology, all types of differentiation epithelial, mesophyllary and trichomatic nectaries can be found, the epithelial ones being the most common type of nectar secretion. The diverse structures, the rare occurrence, and scattered distribution of nectaries in the basal groups indicate convergent evolution.What is the selective advantage of nectar secretion in pollen flowers? It has been proposed (Nepi et al. 2009) that nectar provision is an adaptation to insects which were already accustomed to sugary exudates (such as pollination drops of gymnosperms). An alternative (or supplementary) approach results from the observation that nectar production is limited mainly to the female phase of the proterogynous flowers. It may be concluded (see Erbar & Leins 2013) that the nectar assures the attractiveness of the flower in the non-pollen presenting phase. In addition, during searching for the sparse nectar the insect may come into contact with each stigma thus compensating the economic disadvantage of a choricarpous compared to a coenocarpous gynoecium.