Response of red‐osier dogwood (Cornus stolonifera) seedlings to sodium sulphate salinity: effects of supplemental calcium

Abstract

A greenhouse study was designed to test the effects of sodium sulphate (Na2SO4) on red‐osier dogwood (Cornus stolonifera Michx) seedlings in the presence and absence of additional calcium (Ca2+). Changes in growth parameters, ion and carbohydrate accumulation and cell wall composition were examined. Calcium alleviated the effect of Na2SO4 on shoot height; however, it did not affect the reduction in shoot and root dry weights. An increased level of sodium (Na+) in roots of plant exposed to Na2SO4 was recorded in the presence of supplemental Ca2+ whereas there was no change in potassium (K+) and Ca2+ levels. In shoots of seedlings treated with Na2SO4, the addition of Ca2+ did not affect Na+, K+ and Ca2+ levels. The amount of soluble carbohydrates was increased in leaves of seedlings treated with Na2SO4 both in the absence and presence of supplemental Ca2+. The decrease in cell wall material in response to salt stress was alleviated by Ca2+ in stem tissues although Ca2+ did not alter the changes in hemicellulose and cellulose. Sugar composition of pectins and hemicellulose were modified in stems and leaves by Na2SO4 and/or Ca2+. The results of this study showed that calcium was able to alleviate the effects of salt stress on shoot height and cell wall content of red‐osier dogwood stems. Furthermore, changes occurred in cell wall composition of red osier seedlings treated with Na2SO4.