Laboratorio de Ecología Evolutiva y Biología Floral, Instituto Multidisciplinario de Biología Vegetal (CONICET-Universidad Nacional de Córdoba), Córdoba, Argentina.
Department of Environmental and Plant Biology, Ohio University, Athens, OH, USA.
Plant Biol (Stuttg). 2023 Aug;25(5):671-680. doi: 10.1111/plb.13536. Epub 2023 May 26.
Flower morphology is considered an important factor in species diversification because it may influence the efficiency of pollination in different ways (e.g. attraction and mechanical fit with different groups of pollinators). In the present study, we quantified the variation in flower morphology (i.e. shape and size) of the diverse South American genus Jaborosa Juss. (Solanaceae) in relation to contrasting pollination modes: rewarding pollination either by moths or by generalist small insects versus brood-site deceptive pollination by saprophilous flies. We examined variations of flower morphology in frontal (pollinator attraction) and sagittal (functional fit with pollinators) views in 12 Jaborosa species using geometric morphometric methods and comparative approaches to infer whether flower shape evolution, not attributable to flower allometry or phylogenetic relationship, is associated with shifts in pollination modes. We found remarkable variation in flower morphology among both Jaborosa species and pollination modes, largely in sagittal view. Evolutionary trends in shape of fly-pollinated flowers were mainly attributable to changes in developmental trajectories. Variation in flower architecture facilitated differential pollen placement - on the proboscis of moths, and either on the back or ventral region of saprophilous flies - promoting diversification of the genus. Diversification of shape, independent of size, in most of the studied Jaborosa species would indicate adaptation to contrasting pollination modes.
花形态被认为是物种多样化的一个重要因素，因为它可能以不同的方式影响传粉的效率（例如，以不同的传粉者群体为吸引对象和机械适配）。在本研究中，我们量化了具有南美特色的 Jabrosa Juss. 属（茄科）不同物种花形态（即形状和大小）的变化，这些物种的传粉模式存在差异：蛾类或一般性小型昆虫为有报酬的传粉者，而腐生蝇则通过育幼地欺骗性传粉。我们使用几何形态测量方法和比较方法，从正面（吸引传粉者）和矢状面（与传粉者的功能适配）两个角度，检查了 12 种 Jabrosa 物种的花形态变化，以推断花的形状进化（与花的异速生长或系统发育关系无关）是否与传粉模式的转变有关。我们发现，无论是 Jabrosa 物种还是传粉模式，花形态都存在显著差异，矢状面的差异尤为明显。蝇传粉花朵形状的进化趋势主要归因于发育轨迹的变化。花结构的变异促进了花粉的不同放置——蛾类的喙上，以及腐生蝇的背部或腹面——从而促进了该属的多样化。在大多数研究的 Jabrosa 物种中，形状的多样化独立于大小，这表明它们适应了不同的传粉模式。
