Ashman T-L, Majetic C J
1Department of Biological Sciences, University of Pittsburgh, 4249 Fifth Ave and Ruskin, Pittsburgh, PA 15260, USA.
Heredity (Edinb). 2006 May;96(5):343-52. doi: 10.1038/sj.hdy.6800815.
The characteristics of flowers influence most aspects of angiosperm reproduction, including the agents of pollination and patterns of mating. Thus, a clear view of the forces that mediate floral phenotypic evolution is central to understanding angiosperm diversity. Here, we inform on the capacity for floral phenotype to respond to selection by reviewing published data on heritabilities and genetic correlations for several classes of floral traits (primary sexual, attraction, mating system) in hermaphroditic plants. We find significant heritability for all floral traits but also variation among them, as well as a tendency for heritability to vary with mating system, but not life history. We additionally test predictions stemming from life history theory (eg, negative covariation between male-female traits and flower size-flower number), and ideas concerning the extent and pattern of genetic integration between flowers and leaves, and between the sexes of dioecious and gynodioecious species. We find mixed evidence for life history tradeoffs. We find strong support for floral integration and its relation with floral morphology (actinomorphy vs zygomorphy) and for a decoupling of floral and vegetative traits, but no evidence that modular integration varies with floral morphology. Lastly, we find mixed evidence for a relationship between the level of sexual dimorphism in attraction traits and the between-sex correlation in gender dimorphic plants.
花的特征影响被子植物繁殖的大多数方面，包括传粉媒介和交配模式。因此，清楚了解介导花表型进化的力量是理解被子植物多样性的核心。在这里，我们通过回顾已发表的关于雌雄同体植物几类花性状（原性、吸引力、交配系统）的遗传力和遗传相关性的数据，来介绍花表型对选择作出反应的能力。我们发现所有花性状都具有显著的遗传力，但它们之间也存在差异，并且遗传力有随交配系统变化的趋势，但不随生活史变化。我们还检验了源自生活史理论的预测（例如，雌雄性状与花大小 - 花数量之间的负协变），以及关于花与叶之间、雌雄异株和雌全异株物种的两性之间遗传整合程度和模式的观点。我们发现生活史权衡的证据不一。我们发现有力支持花的整合及其与花形态（辐射对称与两侧对称）的关系，以及花与营养性状的解耦，但没有证据表明模块整合随花形态而变化。最后，我们发现关于吸引性状的性二态性水平与性别二态性植物两性之间相关性的关系的证据不一。
