Effects of NaCl Addition and Aeration Frequency of the Nutrient Solution on the Growth and Transpiration of Cucumber Plants Grown in a Glasshouse and a Growth Chamber

Abstract

Effects of 60 mM NaCI salinity, anoxia and hypoxia on the growth and transpiration of a cucumber (Cucumis sativus L. cv.‘Asomidori No. 5’ and‘Tokiwa Hikari 3A’) plant were studied in a glasshouse under sunlight and in a growth chamber. Both in the glasshouse and the growth chamber, 60 mM NaCI salinity combined with anoxia markedly suppressed growth and transpiration of plants. In the glasshouse, 60 mM NaCI combined with hypoxia also suppressed growth and transpiration of the plants, but the extent of the suppression was less marked. A parallel decline in net assimilation rate and transpiration rate as affected by salinity and anoxia was observed in the growth chamber experiment, suggesting a pivotal role in stomatal resistance to the decline in growth. The accumulation of Na and Cl under salinity was enhanced by the anoxia. Possible involvement of the concentrations of Na and Cl in the variability in fruit growth under salinity is discussed.