PHYLOGENY OF EXTANT GENERA IN THE FAMILY CHARACEAE (CHARALES, CHAROPHYCEAE) BASED ON RBCL SEQUENCES AND MORPHOLOGY

Extant genera of Characeae have been assigned to two tribes: Chareae ( Chara, Lamprothamnium, Nitellopsis, and Lychnothamnus) and Nitelleae ( Nitella and Tolypella), based on morphology of the thallus and reprodu ctive structures. Character analysis of fossil and extant oogonia sugg est that Tolypella is polyphyletic, the genus comprising two sections, one in each of the two tribes. Eleven morphological characters and se quence data for the Rubisco large subunit (rbcL) were used to reconstr uct the phylogeny of genera, including the two sections of Tolypella. Parsimony analysis of the rbcL data, with all positions and changes we ighted equally, strongly supports the monophyly of the Characeae. The two Tolypella sections form a robust monophyletic group basal to the f amily. Transversion weighting yielded the same tree but with a paraphy letic Tolypella. The rbcL data strongly support monophyly of tribe Cha reae but tribe Nitelleae is paraphyletic. Parsimony analysis of morpho logical data produced one unrooted tree consistent with monophyly of t he two tribes; on this tree the Tolypella sections were paraphyletic. Combining morphological with rbcL data did not change the results deri ved from rbcL sequences alone. The rbcL data support the monophyly of the Characeae and Coleochaete, which together form a monophyletic sist er group to embryophytes.