題目：Species diversity in the genus Carex: phylogenetic patterns and the evolution of peatland sedges (スゲ属植物の種分化：ピートランド に生育するスゲの系統と進化)  

講演者：Prof. Marcia J. Waterway (Plant Science Department， McGill University， Canada)  

講演概要：Species richness in Carex is a source of both delight and frustration for those who study the genus， but the origin and maintenance of this diversity are not clearly understood. This talk will present the latest phylogenetic hypothesis for Carex and other genera of tribe Cariceae based on DNA sequence comparisons. The molecular phylogeny uses two non-coding chloroplast DNA regions (trnL intron and trnL-trnF intergenic spacer) plus both internal and external transcribed spacer regions from the nuclear ribosomal genes. The Cariceae tribe is monophyletic， but the genus Carex is polyphyletic. Species of Carex belong to each of three well-supported groups， which may represent distinct genera. Dominant Carex species in peatland habitats are restricted to only a few lineages suggesting evolutionary canalization. Within peatlands， closely related species segregate along environmental gradients of pH and rooting depth in relation to the water table， suggesting that niche differentiation has occurred during or after speciation.  

日時：5月10日（月）16:30-17:30  

場所：21号館1階会議室