New research at the Hortus: the delimitation of the genus Uvaria L.
In the tropical rainforests of Southeast Asia the soursop family (Annonaceae) can be found. The genus Uvaria is a part of this family, but it has not yet been described entirely correctly. That is what Annas Rabbani will be studying during the next four years as a PhD student at the Hortus botanicus Leiden.
In March 2023, Annas Rabbani started his PhD at the Hortus botanicus Leiden. He will be studying the plant genus Uvaria L., which includes more than 180 species within the woody plant family Annonaceae, that has about 2400 known species.
Describing Uvaria
Recent studies have revealed that several other, smaller genera might also be part of Uvaria. To accurately map out Uvaria, Rabbani will focus on two main questions. He will be using molecular methods for a proper delimitation of the genus, so it will become clear which species do and which species don’t belong within Uvaria. Furthermore, he will reconstruct the phylogeny (the natural and evolutionary relationships between the species) of the genus and study how the individual species can be distinguished.
To answer these questions, Rabbani will use various data sets. For example morphological traits, such as hair types, the sepals and petals and the reproductive organs. In addition to this, he will also dive into the DNA of the plants. Because Uvaria does not thrive well in the Dutch climate, Rabbani will mainly be using herbarium material (dried specimens of the plants). He might visit Indonesia to also collect and study live material.
Essential oils and edible fruits
The Annonaceae family is mainly found ine lowland tropical rainforest, an environment that is currently disappearing at a high pace because of oil palm plantations. That is why it is important now to describe the great diversity of plants that occur in that area: the species are disappearing almost quicker than they can be described. If the genus Uvaria has been mapped out, future research can be conducted to study ways we can use the plants. For example, the bark produces essential oils, which could be used for medical purposes. And several Uvaria species produce edible fruits. But before these qualities can be utilised, it is important that the genus has been properly delimited.
Rabbani will be supervised by Sylvia Mota de Oliveira (Naturalis Biodiversity Center) and Roderick Bouman (Hortus botanicus Leiden). His promotor is Paul Keßler (professor by special appointment of botanical bardens and botany of Southeast Asia and prefect of the Hortus botanicus Leiden).
Banner photo Uvaria narum: Wikimedia Commons
Portrait photo Rabbani: Mathilde Simons
Text: Emma Knapper