Biodiv Sci ›› 2007, Vol. 15 ›› Issue (6): 608-617.DOI: 10.1360/biodiv.070091

Special Issue: 植物与传粉者相互作用

• Special Issue • Previous Articles     Next Articles

Food-deceptive pollination in Cymbidium lancifolium (Orchidaceae) in Guangxi, China

Jin Cheng2, 4, Shiyong Liu3, Rong He3, Xinlian Wei3, Yibo Luo1, 2*   

  1. 1 The National Orchid Conservation Center, Shenzhen 518114
    2 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Bei-jing 100093
    3 Yachang Orchids Nature Reserve, Leye,Guangxi 533209
    4 Graduate University of the Chinese Academy of Sciences, Beijing 100049
  • Online:2007-11-20 Published:2007-11-20

Abstract: The orchid family is renowned for its enormous diversity of pollination mechanisms and unusually high occurrence of non-rewarding flowers compared to other plant families. We investigated the pollination biol-ogy of Cymbidium lancifolium during 2005 and 2006 in the Yachang Nature Reserve, Guangxi Province, SW China. Our observations showed that Apis cerana cerana (Hymenopterous, Apidae) was the only pollinator. The bee directly landed on the mid-lobe, then adjusted its direction and entered into the flower. When it found no rewards in the flower, it would exit from the flower with the hind legs forcibly grasping the mid-lobe. The pollinaria together with the anther cap adhered to the thorax by the viscidium during the re-treating process of the bees. The pollinator stayed for 8–71 s in the flower with an average of 18.3 s (N = 11). It is likely that C. lancifolium attracted the bee by the purplish chestnut spots on the labellum (false nectar guides) exploiting the foraging preference of bees. The anther cap that remained on the back of the pollinator blocked the pollinaria from being received by the subsequently visited flower. The height of the anther cap (0.154 ± 0.032 cm) (N = 10) together with thorax of the pollinator (2005: 0.37 ± 0.03 cm (N = 10), 2006: 0.35 ± 0.04 cm (N = 7)) was higher than the entrance of the flower (0.29 ± 0.04 cm) (N = 21), suggesting a possi-bility of anther cap retention for geitonogamy. The reproductive success in the population was respectively 21.13% and 21.28% in 2005 and 2006. Breeding experiments showed that C. lancifolium was self-compatible and there was no significant difference in reproductive success between self-pollination and cross-pollination. There was neither apomixes nor spontaneous autogamy. The pollination success of this species was depend-ent on pollinators. The viability of seed by TTC was estimated as 85.78% (N = 11), and it was not considered to be the key limiting factor for seed germination. Therefore, it is suggested that other factors, such as the density of the pollinators and their pollination frequency, influence the fruit set and maintenance of the popu-lation of C. lancifolium.