J Syst Evol ›› 2015, Vol. 53 ›› Issue (2): 196-202.DOI: 10.1111/jse.12123

• Research Articles • Previous Articles    

Comparison of floral properties and breeding system in dimorphic Buddleja delavayi (Scrophulariaceae)

Gao Chen1 , Wei-Chang Gong1,2, Jia Ge1 , Yang Niu3 , Xin Zhang1,2, Bruce L. Dunn4 , and Wei-Bang Sun1 *   

  1. 1Kunming Botanical Garden, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
    2University of Chinese Academy of Sciences, Beijing, China
    3Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
    4Department of Horticulture and Landscape Architecture, Oklahoma State University, Stillwater, OK, USA
  • Received:2014-03-25 Accepted:2014-07-21 Online:2014-09-29 Published:2015-03-25

Abstract: In this study, floral color, scent composition and emission rate, nectar property, pollinators, and breeding system of dimorphic Buddleja delavayi Gagnep. were investigated. Flower color of B. delavayi was determined using a standard color chart and spectrophotometer, and two distinct color polymorphisms were observed having purple or white flowers. Floral scents of B. delavayi were collected using dynamic headspace adsorption and identified with coupled gas chromatography and mass spectrometry. In total, 28 compounds were identified from the flowers of B. delavayi. The identified scents were divided into three chemical classes based on their biosynthetic origin: terpenes, fatty acid derivatives, and benzenoids. The scent profiles in all individuals were dominated by a few components, such as lilac aldehyde and alcohol, 4-oxoisophorone, benaldehyde, and oxoisophorone oxide. Floral scent composition (benzenoids and terpenes) showed a significant difference between white and purple flower morphs. Flower color–flower scent associations in B. delavayi were identified with two distinct scent profiles in the two color phenotypes. The studies of other floral characteristics (nectar, floral visitors, breeding system, and fruit set) indicated that floral scent emission rate, nectar volume, visitor visitation frequency, and natural fruit set were not significantly different between the two flower color morphs. Bagging experiments revealed that seed production of B. delavayi is dependent mainly on honeybee Apis cerana. Lastly, this study implies that dimorphic floral color in B. delavayi may have been maintained by floral visitors and nectar guide color.

Key words: breeding system, Buddleja delavayi, floral scent, lilac aldehyde, nectar, spectrophotometer