Karyological studies of four Cladophora (Cladophorales, Chlorophyta) species from coastal North Carolina

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

“…11). Although centromeric regions could not be distinguished with certainty, presence of straight and curved chromosomes suggests submedian and median centromeres, respectively (Kapraun & Gargiulo, 1987a The species pair characterized by large-diameter filaments was found to have similar karyotypes. Both C. antennina and C. melagonium have chromosomes ranging from 0.8-1.8 ~m long (Figs 12 and 13), with the longest showing clear evidence of submedian centromeric regions.…”

“…7), and their absence in the latter (Fig. 8), suggests a positive correlation between heterochromatin and genome size (Sarma, 1983;Wik~ & Nordquist, 1970;Kapraun & Gargiulo, 1987a).…”

“…Aceto-orcein staining procedures used for the karyologicai study have been previously described (Kapraun & Gargiulo, 1987a). Documentation by photomicrographs was provided by an Olympus BH2-RFK fluorescence microscope.…”

“…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).…”

Karyological Studies of Cladophoropsis (Siphonocladales, Chlorophyta) from Bermuda

“…However, information from karyotype patterns and basic genome complements was not considered in his phylogenetic conclusions. Cytogenetics techniques developed for vascular plants have been applied successfully to systematics problems in marine algae, providing additional criteria to distinguish closely related species and suggesting possible genetic relationships (Mumford 1975, Mumford and Cole 1977, Cole et al 1983, Kapraun and Freshwater 1987, Kapraun and Martin 1987, Kapraun and Gargiulo 1987a, 1987b. Therefore, data from present and previous karyological studies were used to evaluate these proposed relationships.…”