Shykoff Jacqui A, Kolokotronis Sergios-Orestis, Collin Carine L, López-Villavicencio Manuela
Laboratoire d'Ecologie Systématique et Evolution, CNRS UPRESA 8079, Université Paris-Sud XI, Bâtiment 360, 91405 Orsay Cedex, France.
Oecologia. 2003 Mar;135(1):1-9. doi: 10.1007/s00442-002-1133-z. Epub 2003 Feb 11.
Female fecundity advantage in gynodioecious plants is required for the spread and maintenance of this reproductive system. However, not all reproductive characters show female advantage in all species. We used a meta-analysis to summarise differences between females and hermaphrodites reported from the literature for several reproductive traits. Further we tested three hypotheses, (1) that female plants of species with many ovules produce more seeds per fruit while those with few ovules produce heavier seeds, (2) that females are more pollen limited than hermaphrodites, and (3) that floral sexual size dimorphism is more pronounced in species with few ovules, either because female reproductive success is less limited by pollen availability in such species or because flowers with few ovules require a smaller floral structure to protect the carpels. Overall, females compared to hermaphrodites produced more but smaller flowers, had higher fruit set, higher total seed production, and produced heavier seeds that germinated better. Species with many versus few ovules differed in female advantage for flower size dimorphism, flower number, fruit set and total seed production. However seed size, seed set per fruit and seed germination differences between females and hermaphrodites did not differ significantly between species with few and many ovules. We also found no evidence for differential pollen limitation between females and hermaphrodites. Degree of floral sexual size dimorphism differed significantly between species with few and many ovules. Though pistillate flowers were generally smaller than those of hermaphrodites, species with many ovules showed less difference in flower size between the sexes, suggesting either that the protective role of the perianth constrains the evolution of sexual size dimorphism in species with many ovules or that selection for adequate pollination in species with many ovules impedes the reduction in flower size of females.
在雌雄异株植物中，雌性的繁殖力优势对于这种生殖系统的传播和维持是必需的。然而，并非所有的生殖特征在所有物种中都表现出雌性优势。我们进行了一项荟萃分析，以总结文献中报道的雌性和雌雄同体在几种生殖性状上的差异。此外，我们检验了三个假设：（1）具有许多胚珠的物种的雌性植株每个果实产生更多种子，而胚珠较少的物种产生更重的种子；（2）雌性比雌雄同体更容易受到花粉限制；（3）在胚珠较少的物种中，花的性别大小二态性更为明显，这要么是因为此类物种中雌性的繁殖成功受花粉可获得性的限制较小，要么是因为胚珠较少的花需要较小的花结构来保护心皮。总体而言，与雌雄同体相比，雌性产生更多但更小的花，坐果率更高，总种子产量更高，并且产生的种子更重，发芽率更高。胚珠多与少的物种在花大小二态性、花数量、坐果率和总种子产量的雌性优势方面存在差异。然而，雌性和雌雄同体之间的种子大小、每个果实的结实率和种子发芽差异在胚珠少和胚珠多的物种之间没有显著差异。我们也没有发现雌性和雌雄同体之间存在不同花粉限制的证据。胚珠少和胚珠多的物种之间花的性别大小二态性程度存在显著差异。虽然雌花通常比雌雄同体的花小，但胚珠多的物种在花大小上的性别差异较小，这表明要么花被的保护作用限制了胚珠多的物种中性别大小二态性的进化，要么是胚珠多的物种中对充分授粉的选择阻碍了雌花大小的减小。
Zotero 插件