Open Access

ARTICLE

Reproductive Biology, Seed Formation and Vegetative Propagation of Paeonia peregrina and Ornamental Cultivars

Christina Stoycheva¹, Eva S. Savova², Rosen S. Sokolov², Ekaterina Kozuharova^1,*
1 Department of Pharmacognosy, Faculty of Pharmacy, Medical University, 2 Dunav St., Sofia, Bulgaria
2 Institute of Ornamental and Medicinal Plants, Negovan, Sofia, Bulgaria
* Corresponding Author: Ekaterina Kozuharova. Email:
(This article belongs to the Special Issue: Guardians of Green: Protecting Plants Through the Conservation of Pollinators)

Phyton-International Journal of Experimental Botany https://doi.org/10.32604/phyton.2026.087714

Received 22 June 2026; Accepted 14 July 2026; Published online 22 July 2026

Abstract

Paeonia peregrina Mill. is a medicinal plant of conservation concern in Bulgaria, where its petals and roots are harvested from wild populations for pharmaceutical use. Developing effective propagation methods is therefore essential for its conservation and potential cultivation. This preliminary study investigated selected aspects of the reproductive biology of P. peregrina, including pollination, seed formation, seedling development, and vegetative propagation. Field observations and experiments were conducted during 2024–2025 in a natural population near the town of Boboshevo, southwestern Bulgaria, while propagation trials were performed under ex situ conditions. To assess the role of pollinators, flowers were isolated from insect visitors during the bud stage. Pollinator exclusion resulted in almost complete reproductive failure, with only 0.74% seed set and the production of abortive seeds, whereas freely pollinated flowers achieved a mean seed set of 40.55%. Honeybees (Apis mellifera) were the most frequently observed pollen vectors, while bumblebees and ants were also recorded visiting flowers and buds. These findings indicate a strong dependence on insect-mediated pollination for successful seed production. Seeds sown immediately after ripening germinated in the second spring following sowing, demonstrating a prolonged dormancy period requiring sequential warm and cold stratification phases. Germination exceeded 50%, but seedling growth during the first year was slow. Irrigation and fertilization significantly improved the development of young plants, resulting in greater root biomass and larger underground organs after the second growing season. Vegetative propagation through division proved feasible and reliable, with 100% survival of daughter plants obtained from five-year-old specimens. However, the propagation coefficient was relatively low compared with the cultivated species P. lactiflora, reflecting the limited number of divisible vegetative buds. Nevertheless, transplanted and divided plants successfully regenerated under cultivation. The results demonstrate that P. peregrina relies heavily on pollinators for sexual reproduction and possesses slow but effective pathways for both seed and vegetative propagation. These findings contribute to the development of cultivation strategies that could support conservation efforts, reduce harvesting pressure on wild populations, and ensure a sustainable supply of medicinal plant material. Conserving both native habitats and pollinator communities is crucial to ensuring the long-term persistence of the species.

---

Keywords

Paeonia peregrina; self-pollination; pollen vectors; vegetative and seed propagation specifics; Bulgaria

---