Molecular systematics, evolution, and population biology in the mustard family (Brassicaceae)

The present review summarizes results from the past decade on the systematics, population genetics, and evolutionary biology of the mustard family, Brassicaceae (Cruciferae). The research of various authors is discussed and presented in the context of ongoing and accumulating studies. The review is useful in view of the immensely increasing work on Arabidopsis thaliana, the model species of plant molecular biology, and on important crop plants such as species of Brassica. Traditional and molecular-based phylogenies are critically discussed, new generic alignments are proposed, and groups in need of molecular studies are identified. Unfortunately, knowledge obtained from molecular genetics and development of A. thaliana is only very slowly creeping into the systematics of Brassicaceae. Future directions of research should move beyond assessing generic relationships or limits, and should also address character development and evolution, the molecular basis of various homoplastic characters, the nature of the genome, and many other new challenges that are emerging from detailed molecular studies of A. thaliana.