Cucumber (Cucumis sativus L. cv. Fidelio) grown in sand culture in the greenhouse was trickle-irrigated with nutrient solution containing 0, 10, or 50 mm NaCl. Gas exchange of Individual leaves was measured by a portable infrared gas analyzer et saturating photosynthetic photon flux. Salt at 10 mm had no detectable effect on plant performance, but exposure to 50 mm NaCl caused net CO2 fixation to decline by 33% and 48% in the eighth and ninth oldest leaves, respectively. Stomatal conductance and transpiration rate were also reduced (≈ 50%) In these leaves. These differences, as well as lower leaf water potentials, were associated with a 60% reduction in fruit fresh weight. The relationship between net CO2 fixation and intercellular (substomatal) CO2 concentrations was determined for individual, attached leaves of plants with roots exposed to various concentrations of NaCl in hydroponics. With 50 and 100 mm NaCl, a nonstomatal contribution to the inhibition of photosynthesis at the chloroplast level was Indicated by strong inhibition of CO, fixation at a saturating CO2 concentration. Salt-induced inhibition of CO2 fixation was associated with accumulation of Na+ and Cl-, and lower K+ in the individual leaves examined.

The degree of salt resistance of Pistacia spp. grown in the western United States is not adequately known. This study evaluated seedling growth and ion uptake characteristics of two Pistacia spp. and one hybrid in outdoor lysimeters for two seasons. After 12 weeks, seedling stem elongation of P. atlantica Desf., P. terebinthus L. (three selections), and P. integerrima Stewart × atlantica (referred to as Gold II) was reduced by an average of 33% at soil solution salinity of 12.6 dS·m-1 (or 8.0 dS·m-1 in the saturation extract). Gold II was the most vigorous genotype and produced the greatest biomass in control and high-salt solutions. Decreases in root and stem growth (average of all seedlings combined) occurred at soil solution salinity of 13.8 dS·m-1 (or 8.7 dS·m-1 in the saturation extract). Increasing salinity resulted in a higher root to stem ratio, which was most pronounced in P. terebinthus. Comparatively small but significant differences in leaf Na and Cl concentrations between species and selections occurred. All species limited Na transport to leaf tissue up to 125 meq Na/liter in soil solution, storing the greatest amount in roots. Chloride concentrations on a dry-weight basis were substantially higher in leaves than in roots. Increasing salinity did not affect leaf K and Mg concentrations, whereas Ca was significantly reduced. Leaf Na and Cl concentrations of P. atlantica and P. terebinthus had significant correlation with Na and Cl concentrations in soil solutions (r = +0.83 to +0.94).

Postharvest changes in membrane lipids of Ca 2+ -infiltrated apples (Malus domestica Borkh. cv. Golden Delicious) have been evaluated. Calcium infiltration (2% or 4% w/v CaCl 2 ) improved fruit firmness retention over control (water-infiltrated) fruit following 6 months of 0°C storage and after 7 subsequent days at 20°C. During cold storage, total phospholipid (primarily phosphatidylcholine and phosphatidylethanolamine) and acylated steryl glycoside concentrations increased in Ca 2+ -infiltrated fruit but decreased in control fruit. Seven days following transfer from cold storage to 20°C, total phospholipid concentration remained highest in fruit infiltrated with 4% CaCl 2 . Free sitosterol and steryl glycoside concentrations were generally increased with increasing infiltrated Ca 2+ concentration throughout the postharvest evaluation period. Greater conservation of specific membrane lipid components in the Ca 2+ -infiltrated fruit, both during and after low-temperature storage, may contribute to the well-known beneficial effects of Ca 2+ infiltration in maintaining apple quality.