Pl. Syst. Evol. 259: 81–83 (2006) DOI 10.1007/s00606-006-0433-x

Editorial: Evolution and phylogeny of the Brassicaceae

M. A. Koch1 and K. Mummenhoff2

1Heidelberg Institute of Plant Sciences, Biodiversity and Plant Systematics, University of Heidelberg, Germany 2Department of Biology, Systematic Botany, University of Osnabru¨ck, Osnabru¨ck, Germany

The Brassicaceae is a large plant family (338 scientific research. Since publication of the genera and 3700 species) of major scientific above mentioned symposium textbook on and economic importance. Almost 100 years ‘‘The Biology and Chemistry of the Crucife- after the first taxonomic and systematic trea- rae’’ (Vaughan et al. 1976), there has been no tise on the family of the Brassicaceae (Hayek special platform dedicated to the systematics 1911) and subsequent contributions (Schulz and evolution of this family. We suggest the 1936, Janchen 1942) we are now close to the time is more than ripe to summarize recent first comprehensive and natural system regard- progress in this field. ing the mustard family. The increasing impor- The papers included in this Special Volume tance of Arabidopsis and Brassica as model of Plant Systematics and Evolution were pre- organisms in Plant Sciences has greatly sented during the XVII International Botani- advanced systematics and taxonomy as well cal Congress (IBC 2005) in Vienna, in as evolutionary and developmental research on symposium 8.9 ‘‘Systematics and Evolution the entire family for two reasons: First, the in Brassicaceae’’ The recurring theme in the most modern and recently developed molecu- lectures was the problems which still have to be lar tools developed for the model plants were to be dealt with concerning phylogenetics and made available and have been applied success- character evolution in Brassicaceae. Some fully to wild relatives, and, second, it is contributions concentrated on recent progress important to prove these conclusions reached made in the field of molecular biology provid- for the model plants, also in their wild ing new insights into the evolution of pheno- relatives. types in this family (evo-devo research). In A first attempt to summarize actual knowl- further talks it was explained that hybridiza- edge of the family was provided 30 years ago tion, reticulation, and polyploidy have played (Vaughan et al. 1976). This book described an important role in speciation and differenti- those markers and methods associated with the ation of the Brassicaceae, particularly in Qua- study of evolution in the Brassicaceae which ternary times during periods which were were the most modern and informative at that greatly influenced by glaciation and deglacia- particular time. tion. Another presentation concentrated on During the last 20 years molecular biology molecular markers which can be utilized to and DNA techniques opened new avenues for address biogeographical questions, e.g. source a revolution in plant systematics and evolu- areas of genetic diversity, refugial areas, vicar- tion, and, for the reasons already given, the iant patterns, and colonization routes. Fur- Brassicaceae have been at the spear-head of thermore, results in the field of comparative 82 M. A. Koch and K. Mummenhoff: Editorial: Evolution and phylogeny of the Brassicaceae genomic studies were outlined which furthered This Special Issue is accompanied by two our understanding of genome-co-linearity, databases compiled by WARWICK et al. which duplications, and rearrangements through provide an excellent source for chromosome time. numbers and for verifying nomenclature. This symposium was dedicated to Herbert Consequently, the several papers do not only Hurka on the occasion of his 65th Birthday supply us with a highly current overview of and was in honour of his contributions to various aspects of crucifer evolution and science which have led to a better understand- systematics, but also provide advanced tools ing of evolution in the Brassicaceae. for working with the entire diversity of this The first contribution from EHRENDORFER family. and NEUFFER deals with HURKA’S and The editors of this volume are fully aware collaborators’ influential work. A most actual that various important aspects of crucifer overview on Brassicaceae phylogeny and evolution are not covered by this Special Issue, systematics is provided by AL-SHEHBAZ and i.e. research on self-incompatibility or molec- co-authors and a new tribal system is suggested ular ecology, or even descriptions of the reflecting phylogenetic relationships. This work various ‘‘molecular’’ and ‘‘analytical’’ tools has been complemented recently by two de- and databases. We apologize to our colleagues tailed forthcoming molecular studies (Beilstein whose work, due to limitation of space, could et al. 2006, Bailey et al. 2006). The large unfortunately not be included. number of bio/phylogeographic studies have Finally, we hope that this Special Issue been compiled by KOCH and KIEFER. These provides not only new insights into evolution, data not only provide the basis for phylogeo- but will also encourage and motivate the graphic hypotheses on various taxonomic lev- scientific community to join us in this exciting els, but also facilitate our understanding of the research of Brassicaceae. biogeographic history of the whole family. As We wish to thank each author for so with many other families, the crucifers are promptly agreeing to prepare a manuscript largely affected by hybridization and reticula- of their oral contributions at the Interna- tion, and, consequently, by polyploidization tional Botanical Congress in Vienna 2005, and genome re-organisation. These aspects are SUSANNE WARWICK and colleagues for pro- summarized and reviewed by MARHOLD and viding the databases and also all reviewers LIHOVA´with the focus on species evolution and for their careful and swift response in also by LYSAK and LEXER who concentrate on reviewing the papers. All concerned with genomes and chromosomes. Molecular biology the publication of this Special Issue of Plant has had a tremendous impact on our knowl- Systematics and Evolution worked hand-in- edge and comprehension of plant form and hand making it possible to present this function. BOWMANN’s contribution provides Special Issue less than one year after presen- insights into morphological variation in all tation at the IBC. plant organs, as well as growth habit, mating systems, and physiology, representing the breadth of the Brassicaceae species. References This offers ample opportunity to investi- Bailey C. D., Koch M. A., Mayer M., Mummen- gate the molecular basis of morphological hoff K., O’Kane Jr. S. L., Warwick S. I., evolution in this family. And, as the flower Windham M. D., Al-Shehbaz I. A. (2006) A itself is one of the key innovations in higher Global nrDNA ITS Phylogeny of the Brassica- plant evolution and diversification, NUTT et al. ceae. Mol. Biol. Evol. in press. elucidate the homeotic changes which played a Beilstein M. A., Al-Shehbaz I. A., Kellogg E. A. considerable role during the evolution of (2006) Brassicaceae phylogeny and trichome flowers of Brassicaceae. evolution. Am. J. Bot. (in press). M. A. Koch and K. Mummenhoff: Editorial: Evolution and phylogeny of the Brassicaceae 83

Hayek A. (1911) Entwurf eines Cruciferensystems Addresses of the authors: Marcus A. Koch (e-mail: auf phylogenetischer Grundlage. Beih. Bot. [email protected]), Heidelberg Centralbl. 27: 127–335. Institute of Plant Sciences, Biodiversity and Plant Janchen E. (1942) Das System der Cruciferen. Systematics, University of, Heidelberg, Im Neuen- O¨sterr. Bot. Zeitschr. 91: 1–28. heimer Feld 345, 69120 Heidelberg, Germany. Schulz O. E. (1936) Cruciferae. In: Engler A., Klaus Mummenhoff (e-mail: Klaus.Mummen- Prantl K. (eds.) Die natu¨rlichen Pflanzenfami- hoff@biologie.uni-osnabrueck.de), Department of lien, vol. 17B, Verlag von Wilhelm Engelmann, Biology, Systematic Botany, University of Leipzig, pp. 227–658. Osnabru¨ck, Barbarastrasse 11, 49069 Osnabru¨ck, Vaughan J. G., Macleod A. J., Jones B. M. G. Germany. (eds.) (1976) The biology and chemistry of the Cruciferae. Academic Press, London, pp. 1–355.