摘要
珙桐(Davidiainvolucrata)是中国特有的珍稀濒危植物。目前对珙桐的研究主要集中在珙桐的形态描述、地理分布和种群和群落生态以及引种繁殖等方面。对其传粉生物学等的研究未见报道。花色一直被认为是吸引传粉者的诱物之一。传粉生态学家多利用滤镜、摄像等技术或行为学的方法研究花色与传粉者间的关系。黄酮类是花内色素中最重要的一类物质,并且已经有了成熟的提取分离方法。但还没有人具体地对它的变化与传粉者的访花关系进行研究。该文测定了各个花期的珙桐花序苞片、雄蕊和叶中的总黄酮含量及其组分变化,并对各个时期传粉者的传粉频率进行了观察。结果表明,随着花的发育,苞片、雄蕊和叶中的总黄酮含量都在下降,在雌蕊期膜翅目昆虫访问率高,但没有鞘翅目昆虫。此时黄酮可能同时起到了吸引和防御传粉者的作用。有几个黄酮组分含量在总黄酮中的比率上升,另有几个下降,增加了花与背景叶的对比度,可能强化了吸引传粉者的能力。
Aims Davidia involucrata is a rare and endangered plant endemic in China. Research has fo cused on its geographical distribution, morphological description, population ecology and synecology, introduction, reproduction, etc., but its developmental biology and pollination ecology have rarely been studied. Color has always been considered as an attraction to polhnators. Ecologists formerly studied the relationship between color and pollinator using filters and photography. Flavonoids are one of the most important pigments in flowers, and techniques for extracting and separating flavonoids have been developed; however, there have been no studies of the relationship between flavonoid variation and pollinators＇ visiting frequency. In this paper, we sought to determine whether flavonoids differ significantly and whether flavonoid variation affects pollination. Methods We determined flavonoid composition in bracts, stamens and leaves. We also observed the visiting frequency of pollinators. Important findings With floral development, the general flavonoid content of bracts, stamens and leaves all decreased. There were significant differences between each stage （p 〈 0.001）. The visiting frequency of Hymenoptera was high at the gynoecium stage, but no Coleoptera appeared. Flavonoids at the gynoecium stage may function in defense and inducement. Several flavonoid compounds increased and some others decreased, strengthening the contrast between flowers and leaves. It is likely that the contrast serves to attract pollinators.
出处
《植物生态学报》
CAS
CSCD
北大核心
2007年第1期166-171,共6页
Chinese Journal of Plant Ecology
基金
国家自然科学基金项目(30370149)
四川省科技厅项目(05JY029-107)
四川省教育厅项目(2004A192)
绵阳师院项目(MA2004009)
关键词
珙桐
传粉
花色
黄酮
Davidia involucrata, polhnation, color, flavonoids
