Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence Kansas 66045 USA.
Am J Bot. 2009 Jan;96(1):83-95. doi: 10.3732/ajb.0800066. Epub 2008 Dec 11.
The origin and evolution of the perianth remains enigmatic. While it seems likely that an undifferentiated perianth consisting of tepals arose early in angiosperm evolution, it is unclear when and how differentiated perianths consisting of distinct organs, such as petals and sepals, arose. Phylogenetic reconstructions of ancestral perianth states across angiosperms have traditionally relied on morphological data from extant species, but these analyses often produce equivocal results. Here we describe the use of developmental genetic data as an additional strategy to infer the ancestral perianth character state for different angiosperm clades. By assessing functional data in combination with expression data in a maximum likelihood framework, we provide a novel approach for investigating the evolutionary history of the perianth. Results of this analysis provide new insights into perianth evolution and provide a proof of concept for using this strategy to explore the incorporation of developmental genetic data in character state reconstructions. As the assumptions outlined here are tested and more genetic data are generated, we hope that ancestral state reconstructions based on multiple lines of evidence will converge.
花被的起源和演化仍然是个谜。虽然由花被片组成的无分化花被在被子植物的早期进化中似乎就已经出现，但分化的花被由不同的器官组成，如花瓣和萼片，是何时以及如何出现的尚不清楚。对被子植物祖先花被状态的系统发育重建传统上依赖于现存物种的形态学数据，但这些分析往往产生模棱两可的结果。在这里，我们描述了将发育遗传数据用作推断不同被子植物类群祖先花被特征状态的附加策略。通过在最大似然框架中评估功能数据和表达数据，我们提供了一种研究花被演化历史的新方法。该分析的结果为花被演化提供了新的见解，并为使用该策略探索将发育遗传数据纳入特征状态重建提供了一个概念验证。随着这里概述的假设得到检验和更多遗传数据的产生，我们希望基于多种证据的祖先状态重建将趋于一致。
