Katinas Liliana, Hernández Marcelo P, Arambarri Ana M, Funk Vicki A
División Plantas Vasculares, Museo de La Plata, La Plata, Argentina Laboratorio de Morfología Comparada de Espermatófitas (LAMCE), Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, La Plata, Argentina
Laboratorio de Morfología Comparada de Espermatófitas (LAMCE), Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, La Plata, Argentina.
Ann Bot. 2016 May;117(6):1009-21. doi: 10.1093/aob/mcw033. Epub 2016 Apr 20.
The plant family Asteraceae (Compositae) exhibits remarkable morphological variation in the styles of its members. Lack of studies on the styles of the sister families to Asteraceae, Goodeniaceae and Calyceraceae, obscures our understanding of the origin and evolution of this reproductive feature in these groups. The aim of this work was to perform a comparative study of style morphology and to discuss the relevance of important features in the evolution of Asteraceae and its sister families.
The histochemistry, venation and general morphology of the styles of members of Goodeniaceae, Calyceraceae and early branching lineages of Asteraceae were analysed and put in a phylogenetic framework to discuss the relevance of style features in the evolution of these families.
The location of lipophilic substances allowed differentiation of receptive from non-receptive style papillae, and the style venation in Goodeniaceae and Calyceraceae proved to be distinctive. There were several stages of style evolution from Goodeniaceae to Asteraceae involving connation and elongation of veins, development of bilobation from an initially cup-shaped style, and a redistribution of the receptive and non-receptive papillae.
These developments resulted in bifurcation in the styles of Asteraceae, with each branch face having a different function, and it is suggested here as a mechanism that promoted outcrossing, which in turn led to the great diversification in the family.
菊科植物在其成员的花柱形态上表现出显著的形态变异。由于缺乏对菊科姊妹科——草海桐科和萼角花科花柱的研究,我们对这些类群中这种繁殖特征的起源和演化的理解变得模糊不清。这项工作的目的是对花柱形态进行比较研究,并讨论重要特征在菊科及其姊妹科演化中的相关性。
分析了草海桐科、萼角花科以及菊科早期分支谱系成员花柱的组织化学、脉序和一般形态,并将其置于系统发育框架中,以讨论花柱特征在这些科演化中的相关性。
亲脂性物质的位置使得能够区分可接受的和不可接受的花柱乳头,并且草海桐科和萼角花科的花柱脉序被证明是独特的。从草海桐科到菊科,花柱演化有几个阶段,包括脉的合生和伸长、从最初杯状花柱发育出两裂,以及可接受和不可接受乳头的重新分布。
这些演化导致了菊科花柱的分叉,每个分支面具有不同的功能,本文认为这是一种促进异交的机制,而异交又反过来导致了该科的高度多样化。