Influence of Salinity on the Morphology and Physiology of Amaranthus Dubius [Callaloo] and Capiscum Chinese Var. Scotch Bonnet

The effects of salt stress on the morphology, growth and physiology of Amaronthus dubious [eallaloo] and Capsicum chinense [var. scotch bonnet pepper] were investigated. Various concentrations of sea salt have been used to obtain different salinity levels ofthe soil from 0 to 10 dS m-I • Low levels of salinity at 2 dS m" actually enhanced the growth ofthe plants as measured by the shoot height. Concentrations higher than this inhibited the growth of callaloo. For pepper, salinity level of 4.0 dS rn" was also not that inhibitory. However, salt levels above that level inhibited growth and the older leaves first turned yellowish in colour. There was a positive correlation between the increase in the level ofproline in the plant tissues and salt concentration. Proline content was higher in the shoot than the root. Soluble carbohydrates increased with increasing salinity levels in both callaloo and pepper. The protein levels decreased with increasing salinity levels in eallaloo but remained unchanged in pepper. The activity ofthe enzyme nitrate reductase was inhibited above concentrations of4.0 dS. rn' in both plants and the inhibition was severe in the roots. The results indicate that eallaloo is more sensitive to salt stress than scotch bonnet pepper and slightly different mechanisms are involved in the salt tolerance in callaloo and pcpper.