GROWTH, ION UPTAKE AND GAS-EXCHANGE OF 2 ANNONA SPECIES UNDER SALT STRESS

Growth, ion uptake and CO2/H2O-gas exchange of two-year-old Annona mur icata and Annona cherimola seedlings in response to NaCl salinity were investigated. Vegetative growth of A. muricata was not affected by th e salt treatments and there was no evidence for salt induced leaf necr osis. In contrast, dry matter production of A. cherimola was significa ntly reduced and the old leaves exhibited severe leaf symptoms. NaCl a pplication resulted in an increase of Na and Cl concentrations in all parts of the Annona plants. A, cherimola showed the strongest Na incre ase in leaves and stems. The concentration of Ca and K in leaves and s hoots was lower in salt stressed plants. Net photosynthesis rate as we ll as leaf transpiration decreased during the course of the experiment in the salinity treatments, whereas stomatal resistance increased.