Anatomical characteristics of the buds of different pomegranate cultivars

In Italy, pomegranate is not among the main fruit crops. However, its cultivation significantly increased in the last years, and the most recent data (2020) report a productive area of 1,100 ha with a total harvested production of 15,226 t of fruits. The growing cultivation and the interest of consumers in the nutraceutical properties of the fruit are not aligned with increasing knowledge of some important botanical and physiological aspects of this species. Among these, bud differentiation has been poorly investigated. This research aimed to study the buds’ morphology of four pomegranate cultivars to better clarify the bud differentiation process in the different types of twigs. Within the four pomegranate cultivars, two types of buds were observed: small, thin and with sharper scales on the twigs (short, medium, and long) and large, round and with oval-shaped scales on the spurs; large buds were also noticed on twigs but to a much lesser extent than the small and thin buds. The presence of an undifferentiated meristem, starch grains in the protective scales and two small transition leaves were observed in all the types of buds from summer to endodormancy; no changes were observed in this period apart from the increase in size. The undifferentiated meristem in the buds of all the cultivars indicated the pomegranate behaving as a species adapted for warm, sub-tropical and tropical areas, which differentiate the flowers prior to anthesis, similarly to other Mediterranean species such as olive and fig. However, further studies are needed for this species, especially on the molecular aspects and genetic control of bud differentiation.