Response of grape rootstocks to salinity: changes in root growth, polyamines and abscisic acid.

Abstract

Effects of salinity (0, 50, 100 and 250 mM NaCl) on growth, root:shoot dry mass ratio, osmotic potential (ψπ),electrolyte leakage and contents of Na+ and K+, polyamines and abscisic acid (ABA) were studied in the grape rootstocks Dogridge, 1613, St. George and Salt Creek. In control rootstocks, the root length was highest in Dogridge and contents of K+ and ABA in Salt Creek. Salinity treatments increased root Na+ and decreased K+ content and St. George exhibited highest Na+ content and Na+:K+ ratio. The root:shoot dry mass ratio in all rootstocks increased upto 100 mM NaCl. With increasing NaCl concentration, putrescine, spermine and spermidine contents showed consistent increase and putrescine increase was highest in St. George and spermidine and spermine in the Dogridge and Salt Creek. Under salinity, the ABA content increased in all the rootstocks but more in Salt Creek and Dogridge than in St. George.