Departament of Botany, Institute of Biological Sciences, University of Brasília, Brasília, DF, Brazil.
Departament of Biological Sciences, Institute of Biotecnology, Federal University of Catalão, Catalão, GO, Brazil.
Plant Biol (Stuttg). 2020 Sep;22(5):872-880. doi: 10.1111/plb.13091. Epub 2020 Jul 4.
Enantiostyly is a floral polymorphism in which two floral forms in the same species differ in deflection of the stigma to right or left position. In monomorphic enantiostylous plants, flowers of the two morphs occur within the same individual, usually in the same proportion. In self-compatible species the function of monomorphic enantiostyly is proposed to increase outcrossing rates and offer a reproductive advantage under pollination limitation. Enantiostylous species are usually self-compatible and show heteranthery, with poricide anthers and pollen as pollinator reward; however, there are families, such as Vochysiaceae, that have different characteristics. We analysed the reproductive system and pollination biology of Qualea parviflora and Q. multiflora, two enantiostylous species from the Brazilian Cerrado that have specific morphological and physiological traits. For this, we characterized flower traits, performed hand pollinations and studied floral visitors. We found no differences between morphs in the proportion of flowers, nectar produced or its concentration, pollen quantity and fruit set. Both species were self-incompatible and quite generalist regarding floral visitors. Enantiostyly in self-incompatible plants seems to confer a reproductive advantage by reducing self-interference resulting from stigma clogging. This novel result helps to expand our knowledge on this complex floral polymorphism and opens new avenues for future research on this topic.
偏态花柱是一种花部形态多态性，表现为同一物种的两种花型在柱头偏向右侧或左侧的位置上存在差异。在同型偏态花柱植物中，两种花型的花朵出现在同一植株个体内，通常比例相当。在自交亲和物种中，人们提出同型偏态花柱的功能是提高异交率，并在授粉限制下提供生殖优势。偏态花柱植物通常是自交亲和的，并表现出异型花柱，具孔花药和花粉作为传粉者的报酬；然而，有一些科，如卫矛科，具有不同的特征。我们分析了巴西塞拉多地区两种偏态花柱植物 Qualea parviflora 和 Q. multiflora 的生殖系统和传粉生物学，它们具有特定的形态和生理特征。为此，我们对花部特征进行了描述，进行了人工授粉，并研究了访花者。我们发现两种花型在花朵比例、产生的花蜜量或浓度、花粉数量和结实率方面没有差异。这两个物种都是自交不亲和的，并且对传粉者具有相当的泛化性。在自交不亲和植物中，偏态花柱似乎通过减少柱头堵塞导致的自干扰来赋予生殖优势。这一新颖的结果有助于扩展我们对这种复杂花部多态性的认识，并为该主题的未来研究开辟新的途径。
