Plant Diversity ›› 2022, Vol. 40 ›› Issue (01): 101-108.DOI: 10.1016/j.pld.2021.05.001

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Leaf physiological and anatomical responses of two sympatric Paphiopedilum species to temperature

Jing-Qiu Fenga,b, Ji-Hua Wangc, Shi-Bao Zhanga   

  1. a Key Laboratory of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, China;
    b University of Chinese Academy of Sciences, Beijing, 100049, China;
    c Flower Research Institute of Yunnan Academy of Agricultural Sciences, Kunming, 650205, Yunnan, China
  • Received:2020-12-28 Revised:2021-03-19 Online:2022-02-25 Published:2022-03-12
  • Contact: Shi-Bao Zhang
  • Supported by:
    This work was financially supported by the National Natural Science Foundation of China (31970361), the Applied Basic Research Plan of Yunnan Province (2018FA016), the Science and Technology Plan of Yunnan (2018BB010), and the project for Construction of International Flower Technology Innovation Center and Achievement Industrialization (2019ZG006), and the Project for Innovation Team of Yunnan Province. Thanks to Dr. John A Meadows for proofreading and editing. Thanks to Mr. Jianbo Yang for helping to make the map of species distribution.

Abstract: Paphiopedilum dianthum and P. micranthum are two endangered orchid species, with high ornamental and conservation values. They are sympatric species, but their leaf anatomical traits and flowering period have significant differences. However, it is unclear whether the differences in leaf structure of the two species will affect their adaptabilities to temperature. Here, we investigated the leaf photosynthetic, anatomical, and flowering traits of these two species at three sites with different temperatures (Kunming, 16.7 ± 0.2℃; Puer, 17.7 ± 0.2℃; Menglun, 23.3 ± 0.2℃) in southwest China. Compared with those at Puer and Kunming, the values of light-saturated photosynthetic rate (Pmax), stomatal conductance (gs), leaf thickness (LT), and stomatal density (SD) in both species were lower at Menglun. The values of Pmax, gs, LT, adaxial cuticle thickness (CTad) and SD in P. dianthum were higher than those of P. micranthum at the three sites. Compared with P. dianthum, there were no flowering plants of P. micranthum at Menglun. These results indicated that both species were less resistance to high temperature, and P. dianthum had a stronger adaptability to high-temperature than P. micranthum. Our findings can provide valuable information for the conservation and cultivation of Paphiopedilum species.

Key words: Conservation, Cultivation, High-temperature, Leaf anatomy, Paphiopedilum, Photosynthesis