Karyological Studies of Cladophoropsis (Siphonocladales, Chlorophyta) from Bermuda

Abstract

Karyological investigations of Cladophoropsis membranacea (C. Ag.) Boerg. from Bermuda revealed the presence of 16 chromosomes in vegetative nuclei. Results from this study and previously published information are used to suggest phylogenetic relationships among the Siphonocladales and Cladophorales.Evidence of synchronous mitotic divisions is presented for C. membranacea. Culture material exhibited a late afternoon peak in nuclear divisions. Data indicate that mitotic synchronization is independent of photon fluence rate, but may under photoperiodic control.

A checklist of benthic marine algae of the tropical and subtropical western Atlantic

“…prop. (30) afinis (Howe & Hoyt) Schneider (31) [Acrochaetium afine] barbadensis (Vickers) Woelkerling (32) [occidentalis; Acrochaetium barbadense; A. liagorae (Weber van Bosse) Hamel; A. occidentale; A. vanbosseae; Chantransia liagorae Weber van Bosse, non BGrgesen] bispora (BGrgesen) Garbary (31,33) [Acrochaetium bisporum] botryocarpa (Harvey) Woelkerling (34) codicola (BGrgesen) Garbary (35,36) [Acrochaetium codicola] compta (BGrgesen) Garbary (33,36) [Acrochaetium comptum] corymbijiera (Thuret in Le Jolis) Dixon in Parke & Dixon (31,37) [Acrochaetium bometii] dasyae (Collins) Woelkerling (31,38) dzviesii (Dillwyn) Woelkerling (39) [Acrochaetium daviesii ; A. sagraeana auct., non (Mont .) Bornet] densa (Drew) Garbary (29, 3 1, 33, 40) [Acrochaetium densum] emothrix (BGrgesen) Garbary (33) [Acrochaetium emothrix] globosa (BGrgesen) Garbary (33) [Acrochaetium globosum] gracilis (BGrgesen) Garbary (33,41) [Acrochaetium gracile] hallandica (Kylin) Woelkerling (28,29,31,42,43) [Acrochaetium dufourii ; A. sargassi ; Audouinella sargassi] hormorhiza (BGrgesen) Garbary (33) [Acrochaetium hormorhizum] hoytii (Collins) Schneider (3 1) [Acrochaetium hoytii] hypneae (BGrgesen) Lawson & John (28,31,44,45) [Acrochaetium hypneae; A. seriatum] infestans (Howe & Hoyt) Dixon in Parke & Dixon (46,47) [membranacea auct., non (Magnus) Papenfuss; Acrochaetium infestans ; Colaconema infestans ; Kylinia infestans] laxa (Abbott) Garbary (33,4...…”

Karyology and nuclear DNA quantification of four species ofChaetomorpha (Cladophorales, Chlorophyta) from the western Atlantic

“…Phylogenetic distance (most parsimonious branch length) estimates segregated cladophoralean algae into several closely related groups: (1) Chaetomorpha and Cladophora (Cladophorales); (2) Anadyomene and Microdictyon; (3) Cladophoropsis, and (4) Dictyosphaeria. It seems significant that these groups apparently have different basic chromosome complements (Kapraun & Breden, 1988).…”

“…In the closely related genus Cladophora (Olsen-Stojkovich et al, 1986;Kapraun & Breden, 1988), species show an unusual uniformity of chromosome numbers, with differences in chromosome size resulting in the karyotype complement of one species appearing to be a reduced or enlarged version of that of another (Kapraun & Gargiulo, 1987a, 1987b. These six basic chromosomes include three with median centromeres and three with sub-median ones (Wik-Sj6stedt, 1970).…”

Genetic variation and structure of the endangered freshwater benthic alga Marimo, Aegagropila linnaei (Ulvophyceae) in Japanese lakes

“…24 chromosomes for the material sampled in Japan. Because x = 6 is known to be the basic chromosome number in several related genera in Cladophorales (Sarma 1983;Kapraun and Breden 1988;Hinson and Kapraun 1991), the chromosome number 24 might represent tetraploidy. Although the nuclear phase of the algae we examined is still not certain, tetraploidy may explain the occurrence of more than three alleles found in this study.…”