Evolution of Syncarpy and other morphological characters in African Annonaceae: A posterior mapping approach
Evolution of Syncarpy and other morphological characters in African Annonaceae: A posterior mapping approach
复制标题
DOI：
10.1016/j.ympev.2008.01.018
复制
发表时间：
2008-04-01
影响因子：
4.1
通讯作者：
Chatrou, L. W.
中科院分区：
文献类型：
--
作者：
Couvreur, T. L. P.;Richardson, J. E.;Chatrou, L. W.
先天性的心皮融合或合心皮被认为是一项关键创新，因为它存在于 80% 以上的被子植物中。然而，在木兰科植物中，合果很少进化。为了解释这一特征的进化，提出了合心皮的两种替代进化起源：单个心皮的增殖与中等数量心皮的融合。木兰科番荔枝科为检验这些假设提供了理想的环境，因为两个非洲属，Isolona 和 Monodora，在一个具有多心皮和单心皮属的无孢子科中是合心皮的。除了合果之外，还研究了其他六种形态特征的演变。重建了非洲番荔枝科，特别是伊索罗纳科和莫诺多拉科的系统发育关系。使用最大简约和贝叶斯推理方法对六个质体区域进行测序和分析。使用贝叶斯后验映射方法来研究特征进化，因为它解释了映射和系统发育的不确定性，并且还允许沿着分支的多个状态变化。我们的系统发育分析恢复了一个完全解析的进化枝，包括非洲特有的十二个属，包括伊索罗纳属和莫诺多拉属，它们嵌套在所谓的长枝进化枝内。这是迄今为止在番荔枝科中发现的最大、物种最丰富的非洲属分支。这两个合心皮属被推断为与具有多心皮无顶果雌核属的属为姐妹的进化支，支持了合心皮是由中等数量的心皮融合产生的假设。在研究这两个属的花卉解剖学时，这一假设也得到了支持。番荔枝科提供了在无壳木兰科中唯一明显的合果进化的例子。这里提出的结果可以更好地理解番荔枝科和一般被子植物内合果的进化。由爱思唯尔公司出版
The congenital fusion of carpels, or syncarpy, is considered a key innovation as it is found in more than 80% of angiosperms. Within the magnoliids however, syncarpy has rarely evolved. Two alternative evolutionary origins of syncarpy were suggested in order to explain the evolution of this feature: multiplication of a single carpel vs. fusion of a moderate number of carpels. The magnoliid family Annonaceae provides an ideal situation to test these hypotheses as two African genera, Isolona and Monodora, are syncarpous in an otherwise apocarpous family with multicarpellate and unicarpellate genera. In addition to syncarpy, the evolution of six other morphological characters was studied. Well-supported phylogenetic relationships of African Annonaceae and in particular those of Isolona and Monodora were reconstructed. Six plastid regions were sequenced and analyzed using maximum parsimony and Bayesian inference methods. The Bayesian posterior mapping approach to study character evolution was used as it accounts for both mapping and phylogenetic uncertainty, and also allows multiple state changes along the branches. Our phylogenetic analyses recovered a fully resolved clade comprising twelve genera endemic to Africa, including Isolona and Monodora, which was nested within the so-called long-branch clade. This is the largest and most species-rich clade of African genera identified to date within Annonaceae. The two syncarpous genera were inferred with maximum support to be sister to a clade characterized by genera with multicarpellate apocarpous gynoecia, supporting the hypothesis that syncarpy arose by fusion of a moderate number of carpels. This hypothesis was also favoured when studying the floral anatomy of both genera. Annonaceae provide the only case of a clear evolution of syncarpy within an otherwise apocarpous magnoliid family. The results presented here offer a better understanding of the evolution of syncarpy in Annonaceae and within angiosperms in general. Published by Elsevier Inc.