Molecular analyses on the genetic diversity and inheritance of (−)-α-bisabolol and chamazulene content in tetraploid chamomile (Chamomilla recutita (L.) Rausch.)

By analysing di- and tetraploid chamomile (Chamomilla recutita (L.) Rausch.) accessions using 18 RAPD primers and 16 EcoRI + 3/MseI + 3 AFLP primer combinations genetic similarity (GSD) was estimated in a range of 0.68-0.95 (RAPDs) and 0.74-0.88 (AFLPs), respectively. UPGMA-cluster analysis revealed two main groups and additional sub-clusters according to the origin of germplasms but not to the phytochemical composition. In lines selected for the development of segregating populations for marker development a high level of genetic homogeneity within (GSD ≈ 0.9; H′ ≈ 0.1) but diversity between lines (GSD ≈ 0.7; H′ ≈ 0.5) was detected which facilitated the selection of contrasting parental genotypes with respect to (−)-α-bisabolol and chamazulene content as well as genome composition. Segregation analysis of 841 F2-individuals revealed a monogenic recessive mode of inheritance of the (−)-α-bisabolol and chamazulene content. By bulked segregant analysis three AFLP-markers linked to the (−)-α-bisabolol locus and one RAPD and 17 AFLP markers for the chamazulene content were detected. At least the markers for the chamazulene content are suited for pre-flowering marker based selection procedures.