Leaf Anatomy of Different Peony and Its Environmental Adaptability

Abstract [Objective] We aim to investigate the morphological adaptation characteristics of peony in different habitats to the environment in the plain areas, and to provide references for peony conservation research and screening of high-quality germplasm resources. [Methods] The Central Plain peonies (Paeonia ostii ‘Fengdan’ and P .‘Luoyanghong’) and wild peonies (P . delavayi Franch, P . potanini, P . ludlowii, P . lutea (Tibet), P . lutea and P . qiui) were used as materials, and paraffin section technique was used to observe the leaf structure and analyze the related indexes. [Results] (1) The leaf epidermal morphology of the Central Plain peonies and wild peonies showed varying degrees of variation. The leaves were heterofacial, with the upper and lower epidermal cells were irregularly shaped, and the stomata was uniformly distributed in the lower epidermis. (2) The leaves and cuticles of P . ludlowii were thin. The palisade tissue was underdeveloped. The intercellular space was large and the stomatal density was high. The thickness of leaves, palisade tissue, and sponge tissue of P . lutea was the largest. (3) Stomatal density and epidermal thickness, chlorophyll b and chlorophyll a/b, total chlorophyll and chlorophyll a/b were significantly negatively correlated (P <0.01). Stomatal index is positively correlated with palisade tissue thickness, palisade tissue thickness and leaf thickness, chlorophyll b and total chlorophyll. [Conclusion] The wild peony germplasms except P . ludlowii have strong adaptability to the plain habitats, and the wet structure of P . ludlowii is the main reason why it cannot be cultivated in the plain area.