Gaskett Anne C, Conti Elena, Schiestl Florian P
Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia 2019.
J Chem Ecol. 2005 May;31(5):1223-8. doi: 10.1007/s10886-005-5351-9.
Floral traits such as odor, color, and morphology are important pollinator attractants. Variation in floral traits may influence floral constancy, the tendency of pollinating insects to visit flowers of only one type. We investigated for the first time variation in odor between floral morphs in heterostylous species. We analyzed inter- and intraspecific odor variation in the "pin" and "thrum" floral morphs of sympatric Primula elatior and P. farinosa (Primulaceae). Floral volatiles were sampled with headspace sorption. Quantitative analysis and chemical identification were performed by gas chromatography coupled to mass spectrometry. The species produced different floral bouquets. P. elatior emitted mostly limonene with small amounts of alpha-pinene, myrcene, and sabinene. P. farinosa produced benzaldehyde, 4-oxoisophorone (2,6,6-trimethyl-2-cyclohexene-1,4-dione), benzyl alcohol, and benzyl acetate. These interspecific differences may play a role in promoting floral constancy and maintaining species integrity. Conversely, no differences were detected between the scents of pin and thrum morphs within each species. Heterostyly relies on pollinators visiting both floral morphs. There may be stabilizing selection against divergences in traits that may cause pollinators to develop floral constancy to only one of the floral morphs.
气味、颜色和形态等花部特征是重要的传粉者吸引物。花部特征的变化可能会影响花的忠实性，即传粉昆虫只拜访一种类型花朵的倾向。我们首次研究了异型花柱物种不同花形态之间的气味差异。我们分析了同域分布的高报春和粉质报春（报春花科）“针状花”和“柱状花”花形态的种间和种内气味变化。用顶空吸附法采集花的挥发物。通过气相色谱-质谱联用进行定量分析和化学鉴定。这两个物种产生了不同的花香组合。高报春主要释放柠檬烯，伴有少量的α-蒎烯、月桂烯和桧烯。粉质报春产生苯甲醛、4-氧代异佛尔酮（2,6,6-三甲基-2-环己烯-1,4-二酮）、苯甲醇和乙酸苄酯。这些种间差异可能在促进花的忠实性和维持物种完整性方面发挥作用。相反，在每个物种的针状花和柱状花形态的气味之间未检测到差异。异型花柱依赖传粉者拜访两种花形态。对于可能导致传粉者只对其中一种花形态产生花的忠实性的性状差异，可能存在稳定选择。
