Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, CP 04510, México Distrito Federal, México.
New Phytol. 2010 Feb;185(3):829-40. doi: 10.1111/j.1469-8137.2009.03105.x. Epub 2009 Dec 3.
Although the 6 magnitude and pattern of correlation among floral traits (phenotypic integration) is usually conceived as an adaptation for successful pollination and reproduction, studies on the evolution of plant reproductive systems have generally focused on one or a few characters. If evolutionary transitions between reproductive systems involve morphological floral adjustments, changes in the magnitude and pattern of phenotypic integration of floral traits may be expected. In this study, we focused on the evolutionary dynamics of a complex adaptive trait, the extent of reciprocity (reciprocal placement) among sexual organs in a heterostylous species, and explored the associated changes in phenotypic floral integration during the transition from tristyly to distyly. The extent of reciprocity and both the magnitude and pattern of floral integration were characterized in 12 populations of Oxalis alpina representing the tristyly-distyly gradient. Although the extent of reciprocity increased along the tristyly-distyly transition, the flower size diminished. These adjustments did not affect the magnitude, but did affect the pattern, of floral integration. *Changes in the pattern of floral integration suggested that allometric, functional and pleiotropic relationships among floral traits were affected during this evolutionary transition.
虽然花部特征（表型整合）的 6 个度量及其相关性模式通常被认为是成功传粉和繁殖的适应特征，但植物繁殖系统的进化研究通常集中在一个或几个特征上。如果繁殖系统的进化转变涉及形态花部调整，那么花部特征的表型整合的程度和模式可能会发生变化。在这项研究中，我们关注的是一个复杂适应特征的进化动态，即异型花柱物种中性器官之间互惠程度（性器官的相互排列），并在从三型花柱到二型花柱的转变过程中探索了表型花部整合的相关变化。我们在代表三型花柱-二型花柱梯度的 12 个 Oxalis alpina 种群中对互惠程度以及花部整合的程度和模式进行了特征描述。尽管互惠程度沿着三型花柱-二型花柱的转变而增加，但花的大小却减小了。这些调整没有影响花部整合的程度，但确实影响了花部整合的模式。花部整合模式的变化表明，在这个进化转变过程中，花部特征之间的异速、功能和多效关系受到了影响。
