Evaluation of chlorophyll a fluorescence and leaf temperature in four native tree species under light and heat stress

• Grant number: 10/19457-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2011
• End date: November 30, 2011
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Carlos Alberto Martinez y Huaman
• Grantee: Jorge Luiz Simão Junior
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Global climatic change is one of the issues most currently discussed and a manner of reduce it is the absorption of greenhouse gas, like carbon dioxide, through reforestation projects, because the plants, especially trees, absorb carbon dioxide from the atmosphere. Nevertheless, the knowledge of what plants should be used is important because their ecologic and physiologic characteristics are different according to the specie. Light, carbon dioxide, water and temperature are extremely important for plants because they are the environmental factors that affect the photosynthesis. Therefore, gas exchange occurs with maximum absorption of carbon dioxide and minimum loss of water, avoiding death by dehydration. Four native tree species were used in this work: Aspidosperma polyneuron, Aspidosperma cylindrocarpon, Cariniana legalis and Cariniana estrellensis. Plants of the four species, grown in pots, were exposed to two conditions of luminosity and temperature. The parameters evaluated were fluorescence, photosynthetic pigments and leaf temperature, as well as the parameters of growth. It was observed that plants suffered photoinhibition, but Aspidosperma cylindrocarpon showed greater tolerance among the four species, followed by Cariniana estrellensis. Nevertheless, the behavior of the four species studied is still secondary, because they have slow growth and photoinhibition which was more pronounced in environments with more radiation. (AU)