Increase of male reproductive components with size in an animal-pollinated hermaphrodite, Narthecium asiaticum (Liliaceae)
Increase of male reproductive components with size in an animal-pollinated hermaphrodite, Narthecium asiaticum (Liliaceae)
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DOI：
10.1111/j.1365-2435.2004.00826.x
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发表时间：
2004-02
影响因子：
5.2
通讯作者：
H. Ishii
中科院分区：
文献类型：
--
作者：
H. Ishii
在动物传粉的植物中，由于花粉产量的增加会导致来自同一亲本的花粉粒对胚珠的竞争加剧，因此雌性的功能预计会随着大小的增加而增加，而大量的花会导致两性通婚的增加，从而增加花粉的折扣。迄今为止，许多研究都支持这一预测。然而，在动物传粉植物亚洲花（Narthecium asiatium, Maxim）中，花的雄性生殖成分随着总状花序的大小而增加，而雌性生殖成分则没有增加。这主要是由于总状花序中上部花的相似趋势。中上部花离地高度与总状花序大小有关，较高的花吸引更多的传粉者。因此，在较大的总状花序中，更多的花粉粒从上部花中脱落。此外，花数量的增加可能不会增加该物种的局部配偶竞争和雌雄同体，因为在任何时候，无论总状花序大小，只有少数花具有雄性功能。这可能是即使亚洲蓟是一种动物传粉的植物，上部花的雄性生殖成分也随着大小而增加的原因。下部花的雄性生殖成分没有增加，这可能是由于下部花的高度与总状花序的大小无关。
Summary 1In animal-pollinated plants, female function is expected to increase with size because increased pollen production leads to more competition for ovules by pollen grains from the same parent, and a large flower number results in increased geitonogamy and, in turn, increased pollen discounting. To date, many studies have supported this prediction. 2In Narthecium asiaticum (Maxim), an animal-pollinated plant, however, male reproductive components in flowers increased with raceme size whereas female reproductive components did not. This was mostly because of the similar trend for middle to upper flowers within racemes. 3Height above ground for middle to upper flowers was associated with raceme size, and higher flowers attracted more pollinators. Accordingly, more pollen grains were removed from upper flowers in larger racemes. Furthermore, an increased number of flowers may not increase local mate competition and geitonogamy in this species because only a few flowers function as males at any one time, irrespective of raceme size. 4This may be the reason why male reproductive components of upper flowers increased with size, even though N. asiaticum is an animal-pollinated plant. Male reproductive components of lower flowers did not increase, probably because the height of lower flowers was not associated with raceme size.