Photosynthesis and growth of sweet orange plants as functions of daily temperature amplitude

• Grant number: 09/03749-7
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2009
• End date: April 30, 2011
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Rafael Vasconcelos Ribeiro
• Grantee: Ana Carolina Rosa Bueno
• Host Institution: Instituto Agronômico (IAC). Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). Campinas , SP, Brazil

Abstract

The growth and development of crop plants are regulated by environmental factors, being the temperature one of the most important elements regarding the plant-environment interaction. The aim of this research project is to test the hypothesis that daily temperature amplitude affects the photosynthetic metabolism by changes in daily carbohydrate dynamics, i.e., there is an enhancement of photosynthesis when the consumption/accumulation of carbohydrates is favored by daily temperature variation. Then, a higher photosynthesis and carbohydrate dynamics will improve plant growth. The research will be carried out with Valencia sweet orange scions grafted on Rangpur lime or Swingle citrumelo plants growing in a growth chamber. With exception of temperature, the other environmental conditions (photosynthetic photon flux density, air vapor pressure deficit and photoperiod) will be maintained constant and the same in all temperature treatments. Plants will be subjected to the following temperature regimes (day/night): 25/25ºC; 27.5/22.5ºC; 30/20ºC; 32.5/17.5ºC, being the average temperature constant (25ºC). Plants will remain in each temperature regime for 20 days and during this time some physiological variables, such as CO2 assimilation, transpiration, stomatal conductance, dark respiration, potential and effective quantum efficiency of the photosystem II, photochemical and non-photochemical quenching, apparent electron transport rate, leaf water potential, plant hydraulic conductance, content of photosynthetic pigments, contents of carbohydrates in leaf, stem and roots and leaf photoassimilate exportation. Dry mass partitioning and some morphological traits (height, leaf area, specific leaf mass, stem diameter, number of shoots and shoot length) will be evaluated too. The experimental design will be in random blocks with six replications in a factorial scheme. Data will be subjected to the analysis of variance and mean values compared by the Tukey's test. (AU)

Scientific publications

(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)

PEDROSO, FERNANDA K. J. V.; PRUDENTE, DANIELLE A.; BUENO, ANA CAROLINA R.; MACHADO, EDUARDO C.; RIBEIRO, RAFAEL V.. Drought tolerance in citrus trees is enhanced by rootstock-dependent changes in root growth and carbohydrate availability. ENVIRONMENTAL AND EXPERIMENTAL BOTANY, v. 101, p. 26-35, MAY 2014. (10/14640-3, 09/03749-7)