Exploring the phylogenomics of Dipcadi (Asparagaceae, Scilloideae) and assessing the utility of ITS as a DNA barcode

Abstract Dipcadi (Asparagaceae, Scilloideae) has long presented phylogenetic and taxonomic challenges. A recent study by Chapano et al. (in press) based on ITS sequence data found several non-monophyletic species and an unresolved backbone topology of the genus. In this study, we present the first high-throughput sequencing (HTS) phylogeny of Dipcadi , using data from target capture of the angiosperms353 loci. The sampling is focused on African diversity. Additionally, we provide an updated ITS phylogeny representing 15 Dipcadi species, including 18 newly sequenced accessions. We expand taxon sampling, especially of D. longifolium , to further explore phylogenetic relationships and species limits in the genus. Although the angiosperms353 loci did not fully resolve the backbone topology of Dipcadi , both approaches generated similar topologies with six well-supported clades, but with incongruences regarding deep nodes. We corroborate monophyly of D. marlothii and D. glaucum. Dipcadi longifolium represents a species complex, possibly including D. gracillimum , but we refrain from taxonomic revisions based on the current sampling. Dipcadi viride and possibly D. platyphyllum are paraphyletic, warranting further attention. Our findings confirm that ITS can be effectively employed as a barcode marker in Dipcadi .