Sakai A K, Weller S G, Culley T M, Campbell D R, Dunbar-Wallis A K, Andres A
Department of Ecology and Evolutionary Biology, University of California, Irvine, CA, USA.
J Evol Biol. 2008 Jan;21(1):18-29. doi: 10.1111/j.1420-9101.2007.01439.x. Epub 2007 Nov 12.
Sex allocation theory addresses how separate sexes can evolve from hermaphroditism but little is known about the genetic potential for shifts in sex allocation in flowering plants. We tested assumptions of this theory using the common currency of biomass and measurements of narrow-sense heritabilities and genetic correlations in Schiedea salicaria, a gynodioecious species under selection for greater differentiation of the sexes. Female (carpel) biomass showed heritable variation in both sexes. Male (stamen) biomass in hermaphrodites also had significant heritability, suggesting the potential for further evolution of dioecy. Significant positive genetic correlations between females and hermaphrodites in carpel mass may slow differentiation between the sexes. Within hermaphrodites, there were no negative genetic correlations between male and female biomass as assumed by models for the evolution of dioecy, suggesting that S. salicaria is capable of further changes in biomass allocation to male and female functions and evolution toward dioecy.
性别分配理论探讨了两性如何从雌雄同体进化而来，但对于开花植物性别分配转变的遗传潜力却知之甚少。我们使用生物量这一通用指标以及对柳叶石竹（Schiedea salicaria）狭义遗传力和遗传相关性的测量，来检验该理论的假设。柳叶石竹是一种雌雄异株的物种，正在经历选择以实现两性的更大分化。雌性（心皮）生物量在两性中均表现出可遗传的变异。雌雄同体植株中的雄性（雄蕊）生物量也具有显著的遗传力，这表明了雌雄异株进一步进化的潜力。心皮质量上雌性与雌雄同体之间显著的正遗传相关性可能会减缓两性之间的分化。在雌雄同体植株中，不存在像雌雄异株进化模型所假设的雄性与雌性生物量之间的负遗传相关性，这表明柳叶石竹能够在分配给雄性和雌性功能的生物量上进一步变化，并朝着雌雄异株进化。
