Comparative ecophysiological analysis between species of macroalgae from lotic environments: temperature and irradiance

• Grant number: 01/06139-3
• Support Opportunities: Regular Research Grants
• Duration: August 01, 2001 - March 31, 2004
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Orlando Necchi Junior
• Grantee: Orlando Necchi Junior
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

With this research we propose to tackle ecophysiological aspects of lotic environments, namely: 1) to compare the photosynthetic performance between species and populations, in the field and in the laboratory, involving variations in temperature and irradiance; the field evaluations will be carried out using fluorometry, in terms of effective quantum yield of photosystem II and relative rate of electron transport (ETR), and in the laboratory we will use both techniques, fluorometry and concentration of dissolved oxygen through the technique of clear and dark flasks (rates of gross photosynthesis, liquid and respiration); 2) to analyze the rates of photosynthesis and respiration in relation to the taxonomic group (Bacillariophyta, Chlorophyta, Cyanophyta, Rhodophyta and Xanthophyta) and of morphofunctional characteristics, through the study of representative species from each group and morphological type.As principal justification for the proposition of this project, we should highlight the lack of similar works, in scope and depth, on lotic macroalgae worldwide. The information available is limited to few species, which does not permit broader conclusions and there is still a notable lack of representation of species/populations from tropical regions. In this context, it becomes even more important to analyze, essential ecophysiological parameters (rates of photosynthesis and respiration) under different temperatures and irradiance in a representative number of species and morphological types of the groups of algae well represented in lotic environments. More global and representative information will provide assistance to better interpret the ecological role of these algae in lotic ecosystems. It is proposed to analyze the lotic algae in relation to the morphofunctional characteristics, in a similar way to the model developed for benthic marine macroalgae, analyzing representatives from each morphological type in relation to some characteristics: production (gross and liquid) and respiration, taxonomic group and type of thallus. This will permit better understanding of the adaptations of each morphological type or group of algae to the environmental characteristics, particularly temperature and irradiance. (AU)

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

BAUTISTA, A. I. N.; NECCHI JÚNIOR, ORLANDO. Photoacclimation in a tropical population of Cladophora glomerata (L. ) Kützing 1843 (Chlorophyta) from southeastern Brazil. Brazilian Journal of Biology, v. 68, n. 1, p. 129-136, Feb. 2008. (01/06139-3)

JAIR VIEIRA JR.; ORLANDO NECCHI JR.. Características fotossintéticas de uma população tropical de Nitella cernua (Characeae, Chlorophyta). Brazilian Journal of Plant Physiology, v. 18, n. 3, p. 379-388, 2006-09-00. (01/06139-3)

NECCHI JR‚ O.. Light-related photosynthetic characteristics of lotic macroalgae. Hydrobiologia, v. 525, n. 1, p. 139-155, 2004. (01/06139-3)

AIN. BAUTISTA; O. NECCHI-JÚNIOR. Fotoaclimatação em uma população tropical de Cladophora glomerata (L.) Kützing 1843 (Chlorophyta) do sudeste do Brasil. Brazilian Journal of Biology, v. 68, n. 1, p. 129-136, 2008-02-00. (01/06139-3)

NECCHI JNR‚ O.. Photosynthetic responses to temperature in tropical lotic macroalgae. PHYCOLOGICAL RESEARCH, v. 52, n. 2, p. 140-148, 2004. (01/06139-3)