Variation in the quantity and quality of reward substances produced by flowers influences reproductive success in angiosperms. In this study, a comparative analysis of nectaries and nectar traits (volume, concentration and sugar composition) was performed on the hybrid × and its parental species to identify phenotypic variation that could affect reproductive success. The presence of nectarostomata and two types of nectary cells are significant, as well as the presence of xylem and phloem. Furthermore, possible interspecific differences in the amount of starch and mucilage may be relevant. Interspecific variation in nectar volume and concentration was found, with the hybrid exhibiting the highest concentration. All three taxa presented hexose-dominated nectar. In conclusion, × like its parental species has a functional and anatomically well-formed nectary. Differences in traits such as the amount of starch and mucilage associated with nectar volume, in combination with differences in nectar concentration could have potential consequences for fitness. Our results confirm previous reports on the development of functional structures in hybrid flowers and serve as the basis for future studies testing whether the differences observed here govern the dynamics of competition in hybridization zones.

中文翻译：

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仙人掌科两种花蜜及其自然杂交种的蜜腺微观结构和花蜜产生

花朵产生的奖励物质的数量和质量的变化影响被子植物的繁殖成功。在这项研究中，对杂交×及其亲本物种的蜜腺和花蜜性状（体积、浓度和糖成分）进行了比较分析，以确定可能影响繁殖成功的表型变异。蜜口和两种类型的蜜腺细胞的存在以及木质部和韧皮部的存在都很重要。此外，淀粉和粘液量的种间差异可能是相关的。发现花蜜量和浓度存在种间差异，其中杂交种的花蜜浓度最高。所有三个类群都呈现以己糖为主的花蜜。总之，×与其亲本物种一样，具有功能齐全且解剖结构良好的蜜腺。与花蜜量相关的淀粉和粘液量等性状的差异，加上花蜜浓度的差异，可能会对健康产生潜在的影响。我们的结果证实了之前关于杂交花功能结构发展的报告，并作为未来研究的基础，测试此处观察到的差异是否控制杂交区域的竞争动态。