Morphophysiological Analysis of the Hierarchical Structure of Cystoseira barbata Thalli

Abstract

The hierarchical structure of the thallus of the brown alga Cystoseira barbata from the Black Sea and the relationship between the structure and apparent photosynthesis were studied. The thalli were selected for measurements in different months of the year from three regions of the Crimean shore. The morphological analysis was successively carried out at several levels of the thallus's structure: at the level of axes of different orders, at the level of separate branches, morphological divisions (sum of the main branches, sum of the adventitious branches, the stem) and the whole thallus. The following parameters were measured and calculated for all levels: weight, water content, ash, organic carbon and chlorophylls and c in biomass, surface area, relative surface area, relative (specific) and total photosynthesis (evaluated by the radioactive carbon method). Proceeding from the axial analysis, the authors suggest an example of the determination of morphological and physiological parameters of the whole thallus at the age of 2.5 years.Results of the measurements and calculations revealed that properties of the axes of different orders are essentially different. Properties of the axes of different orders, their number and proportion are in their turn responsible for the properties of the higher levels of the organization of the thallus (branches, divisions, whole thalli). Besides, the axial analysis provides knowledge on the morphophysiological condition of the plant and allows to calculate the carbon flow through the thallus and the population. The axial analysis enables to evaluate the effect of contamination on a certain species and its population. Methodological aspects of the axial analysis are also discussed.In the previous work (Khailov 1979) the structure of the Cystoseira thallus and its transformation in ontogenesis were described in terms of the main and the adventitious branches. However, branches are complex and variable per se. It was formerly shown that their carbon exchange with the environment is determined by the ratio of more elementary structures of different age . The axes of different orders are elementary structures which cannot be subdivided any further. So in the present work we have carried out the axial analysis of the main and the adventitious branches.

Preliminary results on Macroalgae distribution in destructive processes

“…The parameter of a specific surface (S/W) is widely used in the study of macro- phytes' morphology, where S is algae surface area, W is algae weight (MINICHEVA, 1991;FIRSOV, KHAILOV, 1979). To estimate functioning of algae species of different taxons we elaborated (OSKOLSKAYA, 1989) and applied for the first time in the present work the morphological parameter S o .…”

Ontogenetic Trends in Morphologic Parameters of Cystoseira barbata Thalli

“…Two highly important parameters of the thallus, which are closely related to its external chemical exchange, namely the surface area and the relative surface area, were not calculated in the present study, but they have been computed and discussed in detail in another paper devoted to Cystoseira (Firsov and Khailov 1979).…”

“…Indeed, the division by the entire mass implies a tacit assumption that the functional activities of different structures of the thallus are the same. Yet, in Cystoseira, the photosynthetic rates of zero order axes (main stems) and of third and fourth order axes, of which Cystoseira branches largely consist, differ by 4-to 5-fold (Firsov Khailov 1979). Even in old thalli that part of the bio m as s which pertains to third and fourth order branches retains high rates of carbon flow.…”

“…Morphophysiologic analyses complicate the study of substance flow, but they have the advantage of yielding more comprehensive, and hence more attractive, results. An example of such an ecochemical approach to perennial composite-dissected thalli can be found in Firsov and Khailov (1979).…”