樟科植物花部蜜腺与性系统的系统发育分布规律初探

A preliminary study of phylogenetic distribution of floral nectaries and sexual systems in Lauraceae

花内蜜腺是很多被子植物重要的花部器官,有分泌花蜜、吸引传粉者的作用。樟科植物的可育雄蕊蜜腺和退化雄蕊蜜腺两种类型的花内蜜腺呈现与否以及数量在物种间存在明显差异。大部分两性花樟科植物存在两种蜜腺,单性花则往往缺失其中一种蜜腺。利用樟科植物叶绿体基因组构建系统发育树,概述了两种蜜腺及性系统在樟科植物中的系统发育分布规律。并检测了3种樟科植物两种蜜腺分泌的蜜量和含糖量差异。结果显示,樟科植物两性花和单性花有着很明显的分化界限;退化雄蕊蜜腺也随着单性花的出现而在雄花中消失;所测两性花中退化雄蕊蜜腺花蜜分泌量显著高于可育雄蕊蜜腺。

Floral nectary is an important flower organ in angiosperms to secrete nectar and attract pollinators.The presence of staminal nectary and staminodial nectary,and the number of them differed significantly among species.Most hermaphrodite flowers have two types of nectaries;and the unisexual flower plants tend to lack one of them.In this paper,the phylogenetic tree was constructed using chloroplast genome of Lauraceae,and the phylogenetic distribution of two nectary and sexual systems in Lauraceae was summarized.The differences of honey and sugar content secreted by two nectaries of three Lauraceae plants were detected.The results show that hermaphrodite flower and unisexual flowers of Lauraceae had obvious boundaries.Staminodial nectary disappeared in male flowers with the appearance of unisexual flowers.Staminodial nectary secretes more nectar than staminal nectary in three hermaphrodite flowers.