Chemosystematics of the Mniaceae. II. Flavonoids of Plagiomnium Section Rosulata

Abstract

Flavonoids were isolated from gametophytic plants of seven taxa of Plagiomnium section Rosulata, including the two allopolyploids (P. medium subsp. curvatulum and subsp. me- dium) and five of the six haploids (P. affine, P. ciliare, P. elatum, P. ellipticum, and P. insigne). A total of 22 flavonoids were isolated, most of which were C-glycosides of the flavone apigenin. Also detected were glycosides oftheflavones chrysoeriol and luteolin and an anthochlor pigment, chalcone O-glycoside, which represents a first report for bryophytes. Flavonoid profiles based on occurrence of 12 major compounds were species-specific and clustered the plants into three subgroups: 1) the European endemics P. affine and P. elatum, 2) the North American endemics P. ciliare and P. insigne, and 3) the circumboreal P. ellipticum and P. medium subsp. medium plus the high arctic P. medium subsp. curvatulum. A cladistic analysis of these same data was more consistent with prevailing taxonomic views, dividing the section into a ciliate-toothed subgroup and a sharp- toothed subgroup. Because of high similarity offlavonoid profiles between progenitor species and reduced expression offlavonoids in their allopolyploid derivatives, perfect hybrid complementation was not observed. Nevertheless, flavonoid profiles of both subspecies of P. medium do not contradict