CO2 Assimilation Characteristics of Five Prunus Tree Fruit Species1

Abstract

Abstract Photosynthetic CO2 assimilation characteristics of 5 Prunus species were compared with respect to leaf nitrogen content and water use. The mean maximum CO2 assimilation rates of peach, plum, and cherry were all very similar when expressed on a leaf area, leaf nitrogen, and water use basis (1.33–1.37 nmol CO2 cm−2s−1, 6.17–6.75 nmol CO2 mgN−ls−1, 0.19–0.21 nmol CO2 µgH2O−1). In comparison, the mean maximum CO2 assimilation rate of almond was higher when expressed on a leaf area basis (1.80 nmol CO2 cm−2s−1), the same when expressed on a leaf N basis (6.47 nmol CO2 mgN−1s−1), and lower when expressed on a water use basis (0.16 nmol CO2 µgH2O−1). The mean maximum rate of CO2 assimilation in apricot leaves was lower than that of peach, plum, and cherry when expressed on a leaf area (0.67 nmol CO2 cm−2s −1) and leaf N basis (3.76 nmol CO2 mgN−1s−1) but the same when expressed on a water use basis (0.19 nmol CO2 µgH2O−1). The interspecific relationship between leaf N content and leaf CO2 assimilation rate was found to be similar to that described previously for leaves of a single cultivar of peach.