Ordano Mariano, Fornoni Juan, Boege Karina, Domínguez César A
Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275 Ciudad Universitaria, México, DF, CP 04510, México.
New Phytol. 2008;179(4):1183-1192. doi: 10.1111/j.1469-8137.2008.02523.x. Epub 2008 Jun 28.
Floral integration has been deemed an adaptation to increase the benefits of animal pollination, yet no attempts have been made to estimate its adaptive value under natural conditions. Here, the variation in the magnitude and pattern of phenotypic floral integration and the variance-covariance structure of floral traits in four species of Rosaceae were examined. The intensity of natural selection acting on floral phenotypic integration was also estimated and the available evidence regarding the magnitude of floral integration reviewed. The species studied had similar degrees of floral integration, although significant differences were observed in their variance-covariance structure. Selection acted on subsets of floral traits (i.e. selection on intrafloral integration) rather than on the integration of the whole flower. Average integration was 20% and similar to the estimated mean value of flowering plants. The review indicated that flowering plants present lower integration than expected by chance. Numerical simulations suggest that this pattern may result from selection favouring intrafloral integration. Phenotypic integration at the flower level seems to have a low adaptive value among the species surveyed. Moreover, it is proposed that pollinator-mediated selection promotes the evolution of intrafloral integration.
花部整合被认为是一种适应性特征，可增加动物传粉的益处，但尚未有人尝试在自然条件下估计其适应值。在此，研究了蔷薇科四个物种花部表型整合的程度和模式变化以及花部性状的方差协方差结构。还估计了作用于花部表型整合的自然选择强度，并回顾了有关花部整合程度的现有证据。所研究的物种具有相似程度的花部整合，尽管在它们的方差协方差结构中观察到显著差异。选择作用于花部性状的子集（即对花内整合的选择），而不是整朵花的整合。平均整合度为20%，与开花植物的估计平均值相似。综述表明，开花植物的整合度低于随机预期值。数值模拟表明，这种模式可能是由有利于花内整合的选择导致的。在所调查的物种中，花水平的表型整合似乎具有较低的适应值。此外，有人提出传粉者介导的选择促进了花内整合的进化。
