Female reproductive success and the evolution of mating-type frequencies in tristylous populations
Female reproductive success and the evolution of mating-type frequencies in tristylous populations
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DOI：
10.1111/j.1469-8137.2006.01800.x
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发表时间：
2006-01-01
期刊：
影响因子：
9.4
通讯作者：
Barrett, Spencer C. H.
中科院分区：
文献类型：
--
作者：
Hodgins, Kathryn A.;Barrett, Spencer C. H.
在三柱种群中，交配型频率由负频率依赖选择决定，通常导致平衡时的形态比相等。然而，三雄水仙（Narcissus triandrus）通常表现出长花柱（L）偏态，而中花柱（M）偏态较少。本文利用花粉传递模型和自然居群中雌性育性的测量，研究了这些不均匀的形态比例是否与雌性繁殖成功率的变异有关。我们的理论分析表明，形态比例偏态可能是由不同形态之间的母体适合度差异引起的，而这些效应又被不对称的交配放大了。在15个种群中，有9个种群的N.三雄雄蕊的不同变型之间结实率差异显著，但在11个居群中只有2个居群发生花粉限制。M型的平均结实率与其在种群中的频率呈正相关。我们的研究结果表明，交配模式和雌性育性之间的相互作用是负责在形态频率的变化和损失的M型从三柱种群的N。Triandrus。
In tristylous populations, mating-type frequencies are governed by negative frequency-dependent selection typically resulting in equal morph ratios at equilibrium. However, Narcissus triandrus generally exhibits long-styled (L)-biased populations with a deficiency of the mid-styled (M)-morph.Here we used a pollen-transfer model and measurements of female fertility in natural populations to investigate whether these uneven morph ratios were associated with variation in female reproductive success.Our theoretical analysis demonstrated that morph ratio bias can result from maternal fitness differences among the morphs, and that these effects were magnified by asymmetrical mating. In nine out of 15 populations of N. triandrus, seed set differed significantly among the morphs, but pollen limitation occurred in only two of 11 populations investigated. Average seed set of the M-morph was positively associated with its frequency in populations. Flower size was negatively correlated with the seed set of the M-morph.Our results suggest that interactions between mating patterns and female fertility are responsible for variation in morph frequencies and loss of the M-morph from tristylous populations of N. triandrus.