Morphological, phenological and metabolomic profiling of Greyia species
Ethnobotanical studies have documented the particular usefulness of herbal medicines in the treatment of various dermatological conditions. The genus Greyia has been found to offer dermatological benefits and contains three species namely Greyia flanaganii (GF), Greyia radlkoferi (GR) and Greyia sutherlandii (GS). The variation currently observed in plant material obtained and/or sold as GR necessitates that a clear differentiation between the three Greyia species be made in order to prevent adulteration of material and ensure the propagation of chemo types of each species with high activity. The aim of the research project was thus to investigate morphological, phenological and metabolomic differences in cultivated material as there seems to be morphological variation within species with intermediate types in the study population. Initial morphological description indicated different leaf forms and leaf margins. Flowering varies in terms of inflorescence type, density, and flowering time. Distinct evergreen trees were identified and these are linked to GF whereas GR and GS are deciduous. Leaf material was collected from more than 90 individual trees in a cultivation block at the Mothong African Heritage Site in Mamelodi, Pretoria. NMR-based metabolomic analysis indicated that GS and GF separate to some extent but plants from GR overlaps with both GS and GF indicating that GR might be an intermediate species and stressing the importance of identifying chemo types with good activity. Variation in the anti-tyrosinase activity of the ethanolic leaf extracts was evident and specific plants displaying better activity were identified.
Ing, V., Kleynhans, R. and Prinsloo, G. (2020). Morphological, phenological and metabolomic profiling of Greyia species. Acta Hortic. 1287, 49-56