ArgyreiaLour属中的三种牵牛花物种。,A.lycioides(Choisy)Traiperm&Rattanakrajang,A.mekongensisGagnep&Courchet,和A.versicolor(Kerr)Staples&Traiperm,被发现是同时发生和共同开花的。Argyreiamekongensis和A.versicolor是罕见的,而A.lycioides几乎受到威胁,分布在缅甸和泰国各地。我们调查了关键的花卉特征(花卉形态和物候,以及花蜜腺盘和雄蕊毛状体的微观形态),并筛选了推测有助于传粉媒介吸引的重要化合物。我们的发现表明,花卉形态的某些方面(例如,花冠尺寸,肢体存在,和花色)的三个研究同源物表现出显着差异。此外,传粉者的组成似乎受花的形状和大小的影响;花冠管较宽的牵牛花物种被较大的蜜蜂授粉。所有物种的花蜜腺盘的形态相似,而在不同物种中观察到雄蕊毛状体的变化。在所有三个物种中都发现了腺毛,而非腺毛体仅在A.versicolor中发现。组织化学结果表明,每个物种的花蜜腺和雄蕊毛状体中存在不同的化合物,这可能有助于花卉吸引力和防御。这些发现表明,在同伴共同开花的牵牛花物种中,花卉游客之间存在一些隔离,这似乎受到花及其化合物的宏观和微观形态的影响。此外,了解这些同胞共同开花的Argyreia物种的花卉形态和化学引诱剂可能有助于维持其常见的传粉者,以保护这些稀有和濒危物种,尤其是A.versicolor.
Three morning glory species in the genus Argyreia Lour., A. lycioides (Choisy) Traiperm & Rattanakrajang, A. mekongensis Gagnep & Courchet, and A. versicolor (Kerr) Staples & Traiperm, were found co-occurring and co-flowering. Argyreia mekongensis and A. versicolor are rare, while A. lycioides is near threatened and distributed throughout Myanmar and Thailand. We investigated key floral characters (floral morphology and phenology, as well as the micromorphology of the floral nectary disc and staminal trichomes) and screened for important chemical compounds hypothesized to contribute to
pollinator attraction. Our findings demonstrate that some aspects of floral morphology (e.g., corolla size, limb presence, and floral color) of the three studied congeners exhibit significant differences. Moreover,
pollinator composition appears to be influenced by floral shape and size; morning glory species with wider corolla tubes were pollinated by larger bees. The morphology of the floral nectary disc was similar in all species, while variation in staminal trichomes was observed across species. Glandular trichomes were found in all three species, while non-glandular trichomes were found only in A. versicolor. Histochemical results revealed different compounds in the floral nectary and staminal trichomes of each species, which may contribute to both floral attraction and defense. These findings demonstrate some segregation of floral visitors among sympatric co-flowering morning glory species, which appears to be influenced by the macro- and micromorphology of flowers and their chemical compounds. Moreover, understanding the floral morphology and chemical attractants of these sympatric co-flowering Argyreia species may help to maintain their common pollinators in order to conserve these rare and endangered species, especially A. versicolor.