An examination of nectar production in 34 species of Dendrobium indicates that deceptive pollination in the orchids is not popular  

作　　者：Li-Bing Jia Shuang-Quan Huang 

机构地区：[1]Institute of Evolution and Ecology,School of Life Sciences,Central China Normal University,Wuhan 430079,China

出　　处：《Journal of Systematics and Evolution》2022年第6期1371-1377,共7页植物分类学报（英文版）

基　　金：This study was supported by National Natural Science Foundation of China(Nos.32030071,U1402267).

摘　　要：Nectar, the most common floral reward, is generally used to determine whether an orchid species involves deceptive pollination. Estimates of the deceptive pollination systems with nectarless flowers have ranged from one quarter to one third of the nearly 30 000 species of orchids. These estimates, however, are biased towards temperate-zone, usually terrestrial, orchids. Here we investigated nectar production and property in 34 epiphytic orchid species of the Southeast Asian genus Dendrobium. Twenty-one species were observed producing nectar. The amount and sugar concentration (in bagged flowers) of 12 species varied from 0.45 to 2.78 μL and from 8.1% to 31.1%. The nectar was sucrose-dominant, typical of bee-pollinated flowers. Reconstruction of phylogenetic relationship indicated that transition of nectar secretion occurred in the genus. Spur length was positively correlated with flower size but species with relatively long spurs tended to produce small volume of nectar. Nectar production was strikingly variable among and within individuals in some species, suggesting that a vital measurement of bagged and fresh flowers is needed. Given that the quantitative measurement of nectar or floral reward in orchid species remains scarce, an estimate of deceptive pollination systems awaits further survey in diverse genera.

关 键 词：among-and within-species variation in nectar production DENDROBIUM nectar properties nectar secretion transition nectar-rewarding 

分 类 号：Q94[生物学—植物学]