NOZAKI H

ASEXUAL AND SEXUAL REPRODUCTION IN GONIUM-QUADRATUM (CHLOROPHYTA) WITH A DISCUSSION OF PHYLOGENETIC-RELATIONSHIPS WITHIN THE GONIACEAE
J PHYCOL 29 (3): 369-376 JUN 1993

Abstract:
Morphological details of asexual and sexual reproduction in Gonium quadratum Pringsheim ex Nozaki (Goniaceae, Chlorophyta) were observed by light microscopy, based on clonal cultured materials originating from Nepal. In asexual reproduction, the alga exhibited two different patterns of cell cleavage during formation of 8- and 16-celled daughter colonies. Sexual reproduction was heterothallic and isogamous. The gametes bore a tubular mating structure (bilateral mating papilla) at the base of the flagella, and plasmogamy was initiated by the union of the tips of the papillae of the two gametes. The germinating zygote gave rise to four biflagellate gone cells joined in a colony (germ colony). Possible phylogenetic relationships within the Goniaceae at the species level are outlined, mainly on the basis of reproduction characteristics.