Unravelling the role of mate density and sex ratio in competition for pollen
Unravelling the role of mate density and sex ratio in competition for pollen
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DOI：
10.1111/j.1600-0706.2011.19842.x
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发表时间：
2012-02-01
期刊：
影响因子：
3.4
通讯作者：
Cunningham, Saul A.
中科院分区：
文献类型：
--
作者：
Bianchi, Felix J. J. A.;Cunningham, Saul A.
交配密度和性别比是授粉生物学中常用的概念，但并不总是明确区分。在这里，我们建议交配密度应仅捕获指定区域内雄性期花的数量，而忽略雌性期花的数量。性别比是指在一定区域内雄花期和雌花期花的比例，反映了雌性和雌性之间的竞争。我们使用空间显式模拟模型来量化植物传粉系统的交配密度和性别比变化的影响，该系统的特征是花粉损失率高或低以及从传粉者到柱头的沉积率的组合，然后评估授粉邻域的大小。在花粉损失相对较少的高效系统中，雌性之间的竞争至关重要。相比之下，在花粉损失率高的浪费系统中，交配密度成为主导因素，性别比例不再重要。这些模式是在景观和局部尺度上观察到的。低沉积和低花粉损失率的系统与大授粉区相关，而大授粉区随着沉积率和花粉损失率的增加而下降。这些结果表明，应仔细区分交配密度和性别比，并强调花粉损失与沉积率相互作用的复杂方式，而这一点以前尚未被认识到。
Mate density and sex ratio are commonly used concepts in pollination biology, but are not always clearly distinguished. Here we propose that mate density should only capture the number of male-phase flowers in a defined area and ignore female-phase flowers. Sex ratio is the ratio of male and female-phase flowers in a defined area and captures femalefemale competition. We use a spatially explicit simulation model to quantify the effect of variation in mate density and sex ratio for plantpollinator systems characterized by combinations of high or low rates of pollen loss and deposition from pollinator to stigma and then assess the size of pollination neighbourhoods. In efficient systems with relatively little pollen loss, femalefemale competition is of overriding importance. In contrast, in wasteful systems with high pollen loss rates, mate density becomes the dominant factor and sex ratio is no longer consequential. These patterns were observed at both landscape and local scales. Systems with low deposition and low pollen loss rates are associated with large pollination neighbourhoods, which decline with increasing deposition and pollen loss rates. These results show that mate density and sex ratio should carefully be distinguished and highlight the complex way in which pollen loss interacts with deposition rate, which has not previously been appreciated.