DOES SALT TOLERANCE VARY IN A POTENTIAL OILSEED CROP BRASSICA-CARINATA AT DIFFERENT GROWTH-STAGES

The salt tolerance of two salt-tolerant (C90-1191 and P5/80) and two s alt-sensitive (C90-1115 and 77-321) lines of Ethiopian mustard (Brassi ca carinata) (selected on the basis of their performance in germinatin g ability and seedling growth in a screening experiment) was assessed at the adult stage under glasshouse conditions to evaluate the consist ency of salt tolerance at different growth stages of plant life cycle. No difference in response of all four lines differing in salt toleran ce was found to varying concentrations of NaCl in the growth medium, a lthough the latter two lines were slightly better than the former two in shoot dry mass, seed yield or yield components. The relatively good growth of the lines C90-1115 and 77-321 at the adult stage can be rel ated to their lower accumulation of Na, CI and Ca in their leaves. K/N a ratios, Ca/Na ratios, K versus Na selectivity, and Ca versus Na sele ctivity did not prove to be successful criteria in discriminating the lines differing in degree of salt tolerance. In conclusion, salt toler ance in B. carinata varies with the change in stage of its life cycle. Thus selection based at one particular stage may not produce individu als tolerant at all growth stages.