Hydraulic conductivity and photosynthetic capacity of seedlings of Coffea canephora genotypes

Abstract

The aim was to investigate the morphological, photosynthetic, and hydraulic physiological characteristics of different genotypes of Coffea canephora under controlled cultivation conditions. Growth, conductance, and hydraulic conductivity of the root system of 16 C. canephora genotypes were evaluated in Experiment 1 (November 2013). In Experiment 2 (December 2014), in addition to the previous characteristics, gas exchange, photochemical efficiency, leaf water potential, and leaf hydraulic conductivity were investigated in five genotypes. No significant differences were observed in specific leaf hydraulic conductance, stomatal density, or gas exchange. The correlation between root hydraulic conductance and leaf area and dry mass indicates a physiological balance, reflecting the root system's ability to supply water to the aerial parts and maintain leaf water potential and photosynthetic activity during periods of high atmospheric evapotranspiration. These characteristics are important for genotypes cultivated under low water supply and high evaporative demand, even under irrigation.

Keywords

• coffee robusta
• conductance
• photosynthesis
• root system
• water transport