Vegetative Structure and Reproduction of Laurencia nipponica Yamada (Rhodomelaceae, Rhodophyta)

Algae > Volume 6(1); 1991 > Article

Algae 1991;6(1): 1-12.

Ki Wan Nam, Yuzuru Saito, Chul Hyun Sohn

Department of Marine Biology, National Fisheries University of Pusan. Laboratory of Marine Botany, Faculty of Fisheries, Hokkaido University. Department of Aquaculture, National Fisheries University of Pusan

ABSTRACT

Vegetative structure and reproduction of Laurencia nipponica Yamada were studied based on materials from Korea and type locality. The type specimen was also examined. Each axial segment produces four pericentral cells in alternating sequence. Antheridial trichoblasts arising from axial cell give rise to numerous spermatangia with single central nucleus rather than with apical nucleus being common within the genus. The formation of procarp with four-celled carpogonial branch and two sterile groups as well as post-fertilization process is essentially same as those illustrated by previous reports, except that the fertile segment (suprabasal cell) of female trichoblast always produces five pericentral cells. In stichidia, production of tetrasporangia is restricted to the third and fourth pericentral cells among the four, and there are no additional fertile pericentral cells. Each tetrasporangial mother cell (pericentral cell) cuts off two cover cells (pre-sporangial cover cells), followed by tetrasporangial initial and then another cover cell (post-sporangial cover cell). Among the anatomical characters, spermatangia with single central nucleus are unique within the genus Laurencia.

Key words: vegetative structure, reproduction, Laurencia nipponica, pericentral cell, spermatangia, procarp, tetrasporangia