Genetic differentiation between breeding lines, commercial samples and wild populations of Rooibos (Aspalathus linearis (Burm f.) R. Dahlgren)

Abstract

Roobios (Aspalathus linearis (Burm.f.) R. Dahlgren, Fabaceae) is a popular tea plant, so far produced by cultivating vegetatively propagated wild material. Aim of this work was the characterisation of newly derived breeding lines of Rooibos with molecular markers, the determination of their genetic relationships and the differentiation of breeding material to commercial samples and wild populations. Sequence-derived molecular markers were developed and analyzed with HRM (High-Resolution Melting). In total, 91 samples out of five breeding lines, two different accessions of commercial samples and one accession from the wild were analyzed with 11 molecular markers. Discriminant analysis showed a close relationship between breeding lines 16, 27 and 50, whereas the selection 48 was more distant. Lines 16 and 27 seem to be even genetically identical. All selections were distinguishable from the commercial samples and the wild accession. Anyhow, differentiation of lines 32 and 50 was statistically uncertain caused by the higher heterogeneity of these two lines. An improved statistical quality can be reached with additional samples. The genetical analysis is suitable for an identification of vegetatively propagated breeding lines and can be used for optimizing further breeding- and propagation planning.