Abstract
Gasteria currently comprises 29 species that are divided into two sections: sect. Gasteria Duval (with globose flowers) and sect. Longiflorae Haw. (with narrow elliptical flowers). This genus is native to southern Africa along the coastal regions of South Africa – extending into both Namibia and Eswatini. The species delimitation is problematic due to a limited number of morphological diagnostic characters that are phenotypically plastic. Evolutionary relationships in its tribe (Aloeae) have been studied mostly using Sanger sequencing. Despite this, no insight into the infrageneric classification of Gasteria has been gained. The aim of this study was to produce the first robust phylogenetic reconstruction for this genus. Members of Gasteria were collected and prepared for both Sanger sequencing (using rbcLa, matK, trnH-psbA, trnL-F, ycf1 and ITS1) and targeted sequencing (using the Angiosperms-353 kit). Various phylogenetic analyses were constructed from the Sanger sequencing and targeted sequencing data. Topologies generated from Sanger and targeted sequencing IQ-Tree result were broadly concordant sharing several supported clades whereas the ASTRAL species tree revealed that there is very little genetic variation between species. With an average of 165 genes recovered from targeted sequencing, new observations of the evolutionary relationships of Gasteria were provided...
M.Sc. (Botany)