Cytochemical studies on portuguese carrageenophytes (Gigartinales, Rhodophyta)

Abstract

In opposition to the relatively hard cell walls of other algae, those of the majority of red algae are flexible and soft, what is due to the co-existence of great quantities of amorphous material and relatively scarce fibrilar components. The intercellular matrix of carrageenophytes is mainly composed of highly sulphated polygalactans, with D-galactose and anhidro-D-galactose, in contrast with the less sulphated agars, where the anhydro-L-galactose is predominant. In the scope of a larger work on the carrageenophytes of the Portuguese coast, chemical and spectroscopic analysis (vibrational and nuclear resonance spectroscopy) was carried out to the extracted and purified phycocolloids of these algae. As a complement of this work, the results of a cytochemical study on distribution of the main components of cell wall and intercellular matrix in the thalli are herein presented for the following carrageenophytes: Chondracanthus teedei var. lusitanicus, Gigartina pistillata, Gymnogongrus crenulatus and Ahnfeltiopsis devoniensis.