FUNCTIONAL DIOECY AND ANDROMONOECY IN SOLANUM
FUNCTIONAL DIOECY AND ANDROMONOECY IN SOLANUM
复制标题
DOI：
10.2307/2409175
复制
发表时间：
1989-01-01
期刊：
影响因子：
3.3
通讯作者：
SYMON, DE
中科院分区：
文献类型：
--
作者：
ANDERSON, GJ;SYMON, DE
对澳大利亚特有的 19 种双性植物进行的实地和实验室研究有助于阐明茄属的雄花雌雄同株、雌雄异株和雌雄异体的性质和进化。有十种是雌雄同花的；通常，这些物种的花序具有单一的大型雌雄同体基部花和 12-60 个远端较小的雄花。我们认为，雄花同花的条件部分源自雌雄同体花的祖先，部分是通过花的半不育作用，但主要是通过添加雄花。据推测，由此产生的较大花序既可以吸引也可以夹带传粉媒介，从而在雌雄同体花中产生更多或更高质量的种子集和/或使雄花的花粉更加分散。我们认为，雌雄同体也可能有助于减少自交。其他九个物种在形态上是雌雄异株，但在功能上是雌雄异株。在这些物种中，雄花与雄花同花异株物种的雄花一样，具有具有丰富三孔花粉和高度减少的雌蕊的花药。形态上雌雄同体的花在功能上是雌蕊并且单独生于花序中，并且它们具有带有无孔花粉的花药。无孔的花粉虽然有活力，但永远不会发芽，并且被假设保留在雌花中，作为对无花蜜的茄属花中传粉者的奖励。研究具有花粉二态性的所有其他茄属物种，其中一种花粉形态是无孔的，最好也将其视为功能雌雄异株。我们的结论是，没有证据表明茄属雌雄异体。对其他科的审查表明，在任何其他被子植物群体中，这种不寻常的繁殖系统也几乎没有得到支持。初步分析表明，茄属植物中雄花雌雄同株和雌雄异株是多系的。此外，雌雄同体很可能源自雌雄同体的祖先，也可能源自雌雄同体的祖先。
Field and laboratory studies of 19 diclinous species endemic to Australia help to clarify the nature and evolution of andromonoecy, androdioecy, and dioecy in the genus Solanum. Ten species are andromonoecious; typically these species bear inflorescences with a single, large basal hermaphroditic flower and 12-60 distal, smaller staminate flowers. We suggest that the andromonoecious condition was derived from hermaphroditic-flowered ancestors in part by hemisterilization of flowers but largely by addition of staminate flowers. The resultant larger inflorescences are hypothesized to serve both to attract and to entrain pollinators, yielding more or higher-quality seed set in hermaphroditic flowers and/or greater dispersion of pollen from staminate flowers. We suggest that andromonoecy may also serve to reduce selfing. Nine other species are morphologically androdioecious but functionally dioecious. In these species, staminate flowers, like those of the andromonoecious species, bear anthers with copious tricolporate pollen and a highly reduced gynoecium. The morphologically hermaphroditic flowers are functionally pistillate and borne singly in inflorescences, and they bear anthers with inaperturate pollen. The inaperturate pollen, although viable, never germinates and is hypothesized to be retained in pistillate flowers as a reward to pollinators in the nectarless Solanum flowers. All other species of Solanum studied with pollen dimorphism in which one pollen morph is inaperturate are also best treated as functionally dioecious. We conclude that there is no evidence for androdioecy in Solanum. A review of other families suggests that there is little support for this unusual breeding system in any other angiosperm group either. Preliminary analyses suggest that andromonoecy and dioecy are polyphyletic in Solanum. Furthermore, dioecy is as likely to have arisen from hermaphroditic as from andromonoecious ancestors.