Age-related Morphophysiology of Brown Algae (using the example of representatives of Fucus and Laminariaceae). Some Views, Ideas and Results of the Last Millennium

Abstract

As a result of our own comprehensive research (1979–1999) and generalization of literature data, a fairly complete picture of age-related changes in structure and function in representatives of four families of brown algae, having different morphology, life expectancy and growth type, was obtained. Representatives of the Fucaceae Ag. family (Fucus evanescens C. Ag., Pelvetia wrightii Okam; семейства Sargassaceae (Decne.) Kutz.: Coccophora langsdoerfii (Turn.) Grev., Sargassum pallidum (Turn.) C.Ag., Sargassum mijabei Yendo; семейства Cystoseiraceae Kutz: Cystoseira crassipes (Turm.) C. Ag., Cystoseira barbata (Good, et Wood.) Ag. and the Laminariaceae (Bory) Rostaf. family: Laminaria japonica (J.E. Areschoug), Laminria cichorioides (Miyabe), Laminaria saccharina (L.) Lamour [currently, these species have been renamed and assigned to the genus Saccharina – Saccharina japonica, Saccharina cichorioides, Saccharina latissima, respectively] were selected as research objects. Methods have been developed for determining the age of entire thalli and individual morphological parts for a number of brown algae. The stages of growth, development, and aging of leaf-like plates, branches, trunks and entire thalli of algae are identified. For the first time, age-related changes occurring in the assimilation tissue of various parts of the thallus have been identified; age-related changes in the nucleus, vacuolar system, mitochondria and chloroplasts located at different distances from the surface. The preservation of a high level of structural organization of chloroplasts and photosynthetic activity at late stages of development in apically growing fucus algae has been established, which distinguishes them from intercalary growing kelp and aging leaves of higher plants. Interdependent age-related changes in the level of water content, organic and mineral substances were revealed. Data were obtained on the size-age composition and surface area of populations of various species of fucus and kelp algae. The research results can be used to assess the physiological state of an individual plant, its part and the phytocenosis as a whole, both normally and under various natural and anthropogenic influences, which is necessary, firstly, to obtain the production characteristics of the population, and secondly, during the artificial cultivation of algae and, thirdly, when choosing bioconcentrator organisms or environmental pollution monitor organisms.