In vivo selection for salt tolerance in Coleus blumei

The aim of the investigation was to examine by in vivo screening the potential for salt tolerance in a selected cultivar of the amenity annual, Coleus blumei. Seedlings were placed on a capillary mat soaked in salinized nutrient solution. An initial dose response over the range 0-120 mM NaCl showed that at 90 mM NaCl only 15% of seedlings survived. A large scale screen of seedlings at 90 mM produced a number of survivors of which about 2% grew normally. Cuttings from these survivors showed more tolerance than cuttings from unselected plants. Seed progeny from some of these surviving plants were vegetatively more vigorous in the presence of 90 mM NaCl than seed progeny from unselected plants. Using this simple technique it was possible to screen large numbers of seedlings for salt tolerance in this species. It is suggested that the technique could also be used to screen for a wide range of other characters.