Evaluation of the subtribes Moricandiinae, Savignyinae, Vellinae, and Zillinae (Brassicaceae, tribe Brassiceae) using chloroplast DNA restriction site variation

Abstract

Chloroplast DNA restriction site data was used to assess relationships among 21 taxa of the subtribes Moricandiinae, Savignyinae, Vellinae, and Zillinae (tribe Brassiceae, Brassicaceae). A total of 301 restriction site mutations was observed, with 154 (51.2%) phylogenetically informative. Cladistic analyses, based on Wagner and Dollo parsimony, indicated two major clades. One of these, the Vellinae–Zillinae clade, included members of the Vellinae and Zillinae, with a clarification of the positions of certain genera. The second, the Brassicinae : Rapa–Oleracea clade included Brassica rapa, Moricandia, Pseuderucaria, and Rytidocarpus. The position of Henophyton (Savignyinae) was not clearly resolved. Within the Vellinae–Zillinae clade, two main lineages were evident: (i) Vellinae-core clade, which includes Boleum, Carrichtera, and Vella (all members of the Vellinae) and Euzomodendron (Savignyinae); (ii) Zillinae clade, which includes Fortuynia, Physorrhynchus, Zilla (all Zillinae), and Foleyola and Schouwia (assigned to Moricandiinae and Vellinae, respectively). The positions of Psychine and Succowia (both assigned to Vellinae) were not clearly resolved in the strict consensus but were aligned with the Vellinae-core clade in almost all of the most-parsimonious Wagner trees. The cpDNA data did not support the current separate subtribal ranking for the Moricandiinae but instead revealed the genetic similarity of Moricandia, Pseuderucaria, and Rytidocarpus to subtribe Brassicinae. Key words: Brassicinae, Moricandiinae, Savignyinae, Vellinae, Zillinae, molecular systematics.