Home – Home – Jornals – Contemporary Problems of Ecology 2020 number 3

For a long time Amaryllidaceae served as a textbook example of monopodially growing bulbs. The main argumentation in favor of this viewpoint was the position of the first leaf of the innovation bud in Galanthus : it was not placed with its abaxial side to the inflorescence stalk. The discussion on monopodial or sympodial innovation was continued for more than 150 years, and was completed by the victory of the sympodial model. Nevertheless, the variability of phyllotaxis of the innovation bud in Amaryllidaceae did not receive satisfactory explanation by nowadays, that brings actuality to our research. We have reviewed and re-discovered the prophylls of the innovation bud throughout all the Amaryllidaceae family, leading to strict homologization of these leaves in different clades of the family. By the means of comparative structural morphology we rendered the universality of the sympodial model of bulb innovation in all the members of Amatyllidaceae. Based on the results of the provided study, we have postulated, that the prophyll of the innovation bud undergoes the reduction from well-developed green leaf (photoprophyll) through lower scales (cataprophylls) to complete ablation (phantom prophyll). Moreover, we revealed, that the prophyll morphological characters are synapomorphies for the principal geographical clades of Amaryllidaceae (established according to molecular phylogeny data). The major variability of the prophyll structure we documented for the African tribes of Amaryllidaceae. It is important to mention, that the postulated row of morphological reduction of the prophyll could not be referred to as the row of evolutionary events. As for the common ancestor of Amaryllidaceae, we propose the polymorphic state with different degree of the prophyll development. Further evolution lead to stabilization of the prophyll morphology in the majority of geographical clades, but African Amaryllidaceae. Correspondingly, our data undoubtedly proved the model of sympodial innovation for the bulbs in all the Amaryllidaceae family.