Seed weight and optimal imbibition period for some herbaceous peony (Paeonia spp.) species native to Serbia

Herbaceous peonies are plant species with high ornamental and medicinal value. Due to their endangerment, wild peonies are protected by law in Serbia. Possible ways to protect them are propagation and/or cultivation. Peonies can be propagated vegetatively (by rhizome division) or generatively (with seeds). As peony seeds have a double dormancy and their germination is a long-term process, it is important to determine which seed characteristics and pre-treatments have a positive effect on germination. Since peony seed weight is an important seed characteristic, and imbibition period is an effective pre-treatment, the aim of this study was to evaluate the peony species native to Serbia, and to determine seed mass, seed imbibition capacity, the influence of seed weight on imbibition and the influence of habitat on the studied parameters, as the mentioned parameters have hardly been studied for the tested species. The research was conducted in 2021. on three peony species native to Serbia (Paeonia tenuifolia L.-fern leaf peony or steppe peony; Paeonia peregrina Mill.-Balkan peony or Kosovo peony and Paeonia daurica Andrews). According to our one-year research, there was no statistically significant difference in seed weight depending on the natural habitat within the species and also not between P. peregrina and P. daurica. A significant difference was found in seed weight between steppe peonies and the other two studied species. In agreement with our results, the optimal imbibition time is two to three days for P. peregrina and one to two days for P. tenuifolia and P. daurica. The findings can be used as preliminary research for future peony germination studies.