Pollen and resource limitation in a gynodioecious species
Pollen and resource limitation in a gynodioecious species
复制标题
DOI：
10.3732/ajb.92.3.487
复制
发表时间：
2005-03-01
影响因子：
3
通讯作者：
Mutikainen, P
中科院分区：
文献类型：
--
作者：
Asikainen, E;Mutikainen, P
花粉或资源可用性的植物性别形态之间的差异可能会影响它们的相对适应性，从而影响二态性物种的性别比。在雌雄同体和雌性植物共存的雌雄异株物种中，多种因素（例如，雌雄同体的自体受精或稀有性或传粉者对雌性的歧视）可能会导致雌性比雌性植物更强的花粉限制。另一方面，在低营养条件下，雌性比雌雄同体更优越。针对雌性频率不同（4.4-23.0%）的几个种群，测试了补充人工授粉和资源添加对自花雌花异株多年生天竺葵（Geraniaceae）繁殖产量的影响。花粉和资源的可用性都限制了坐果和每株植物产生的种子数量；然而，结籽数（即每个果实产生的种子数量）仅受资源限制。由于雌性花粉限制与雌性频率无关，因此我们的结果表明雌性花粉限制并不取决于产生花粉的雌雄同体的频率。此外，由于花粉和资源的可用性限制了两种性别形态的繁殖产量，这些因素可能不会对 G. sylvaticum 雌花异株的维持和进化产生显着贡献。
Differences between plant sex morphs in pollen or resource availability may affect their relative fitness and thereby the sex ratio of dimorphic species. In gynodioecious species, in which hermaphroditic and female plants coexist, a variety of factors (e.g., hermaphrodite self-fertility or rarity or pollinator discrimination against females) might be expected to lead to stronger pollen limitation in females than in hermaphrodites. On the other hand, females have been found to be superior compared to hermaphrodites in low-nutrient conditions. The effects of supplemental hand-pollination and resource addition on the reproductive output of the self-fertile gynodioecious perennial Geranium sylvaticum (Geraniaceae) were tested for several populations that differ in their female frequency (4.4-23.0%). Both pollen and resource availability limited fruit set and the number of seeds produced per plant; however, seed set (i.e., the number of seeds produced per fruit) was limited only by resources. Because pollen limitation in females did not correlate with female frequency, our results suggest that pollen limitation in females does not depend on the frequency of the pollen-producing hermaphrodites. Furthermore, because pollen and resource availability limited reproductive output of both sex morphs, these factors may not contribute significantly to maintenance and evolution of gynodioecy in G. sylvaticum.