Evolution of syncarpy in angiosperms: theoretical and phylogenetic analyses of the effects of carpel fusion on offspring quantity and quality
Evolution of syncarpy in angiosperms: theoretical and phylogenetic analyses of the effects of carpel fusion on offspring quantity and quality
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DOI：
10.1046/j.1420-9101.2002.00414.x
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发表时间：
2002-07-01
影响因子：
2.1
通讯作者：
Willson, MF
中科院分区：
文献类型：
--
作者：
Armbruster, WS;Debevec, EM;Willson, MF
合心皮的重复进化是被子植物大进化的主要特征之一。我们提出了新的系统发育和理论分析的结果，以评估的频率和性质的过渡到合心果，和可能的优势，合心果在各种生态条件下的离果。利用最近的分子估计被子植物的有性生殖，我们确定，至少有17个独立的进化过渡从离体结实到合心结实已经发生，这些过渡的约四分之三允许花粉管之间的心皮和受精胚珠，否则将被留下未受精。大多数这些转变也加剧了花粉之间的竞争，可能提高后代的健身。高比例的进化转变，促进花粉竞争和花粉管进入所有心皮支持的假设，syncarpy的主要优势是在增加后代的质量和数量。通过分析和模拟研究，更彻底地评估了合心果的潜在优势。这表明，在边缘授粉条件下，同心结实比离心结实具有优势，即能增加子代数量，但随着授粉次数的增加，其优势逐渐减弱。后代质量优势在更广泛的条件下持续存在，包括在相当高的授粉率下。
The repeated evolution of fused carpels (syncarpy) is one of the dominant features of angiosperm macroevolution. We present results of new phylogenetic and theoretical analyses to assess the frequency and nature of transitions to syncarpy, and the possible advantages of syncarpy over apocarpy under a variety of ecological conditions. Using a recent molecular estimate of angiosperm phylogeny, we ascertained that a minimum of 17 independent evolutionary transitions from apocarpy to syncarpy have occurred; about three-quarters of these transitions allowed pollen tubes to cross between carpels and fertilize ovules that would otherwise be left unfertilized. Most of these transitions also intensified competition between pollen, potentially enhancing offspring fitness. The high proportion of evolutionary transitions promoting pollen competition and pollen-tube access to all carpels supports the hypothesis that the main advantage of syncarpy is in increasing offspring quality and quantity. The potential advantages of syncarpy were more thoroughly evaluated by analytical and simulation studies. These showed that the advantage of syncarpy over apocarpy involving increased offspring-quantity held under conditions of marginal pollination and declined with increasing pollination. The offspring-quality advantage persisted over a wider range of conditions, including under quite high pollination rates.