J Syst Evol ›› 2023, Vol. 61 ›› Issue (3): 530-537.DOI: 10.1111/jse.12916

• Research Articles • Previous Articles     Next Articles

Floral scent emission is the highest at the second night of anthesis in Lonicera japonica (Caprifoliaceae)

Hui-Hui Feng1, Xiao-Yue Wang2, Yi-Bo Luo3, and Shuang-Quan Huang1*   

  1. 1 Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan 430079, China
    2 Key Laboratory of State Forestry Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China, School of Life Sciences, Guizhou Normal University, Guiyang 550025, China
    3 State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    *Author for correspondence. E-mail:hsq@mail.ccnu.edu.cn
  • Received:2022-08-31 Revised:2022-09-19 Online:2022-09-22 Published:2023-05-01

Abstract: Floral color change in diverse plants has been thought to be a visual signal reflecting changes in floral rewards, promoting pollinator foraging efficiency as well as plant reproductive success. It remains unclear whether olfactory signals co-vary with floral color change. We investigated the production rhythms of floral scent and nectar associated with floral color change in Lonicera japonica. The flowers generally last 2-3 days. They are white on opening at night (N1) and become light yellow the following day (D1), yellow on the second night (N2), and golden on the second day of flowering (D2). Our measurements in the four stages indicated that nectar production decreased significantly from N1 and D1 to N2 and D2, tracking the floral color change. A total of 34 compounds were detected in floral scent and total scent emission was significantly higher in N2 than in the other three stages. The scent emission of three major compounds, Linalool, cis-3-Hexenyl tiglate, and Germacrene D was also significantly higher in N2, but the relative content of Linalool decreased gradually, cis-3-Hexenyl tiglate increased gradually, and the relative content of Germacrene D did not differ among the four measured stages. Greater scent emission by night than by day suggested a strong olfactory signal to attract nocturnal hawkmoths, the effective pollinators. However, floral scent rhythms in the four stages did not match the color change and nectar secretion, suggesting that floral color (visual) and scent (olfactory) in this species may play different roles in attracting or filtering various visitors.

Key words: floral color change, floral scent change, Linalool, Lonicera japonica, nectar dynamics, scent emission rhythm