RESPONSES OF SOME LOCAL EXOTIC ACCESSIONS OF LENTIL (LENS-CULINARIS MEDIC) TO SALT STRESS

Assessment of salt tolerance at all growth stages is crucial to determine the overall tolerance of a crop. Salt tolerance of five tolerant ILL 5845, ILL 6451, ILL 6788, ILL 6793 and ILL 6796, three moderately tolerant ILL 6431, ILL 6770 and ILL 6784, and three sensitive ILL 6210, ILL 6439 and ILL 6778 accessions selected at the germination and seedling stages was assessed at the adult stage using sand culture salinized with 0, 30, or 60 mol m-3 NaCl. A positive correlation was observed between degrees of salt tolerance at different growth stages in three tolerant accessions ILL 6451, ILL 6788 and ILL 6793 which produced significantly higher seed yield than the other accessions. This was also affirmed in three sensitive and two moderately tolerant accessions (ILL 6770 and ILL 6784) whose salt sensitivity was conferred consistently at all growth stages. In contrast ILL 5845, and ILL 6796 which were highly salt tolerant and ILL 6431 which was moderately tolerant at the early growth stages had relatively low seed yield, hence showing a negative correlation between tolerances at different growth stages. High yielding accessions ILL 6451, ILL 6788 and ILL 6793 in general, accumulated higher Na+ and higher or moderate Cl- in their shoots compared with the other accessions, thus showing a typical halophytic mechanism of salt inclusion. K/Na ratios of all the tolerant, moderately tolerant and sensitive accessions except ILL 6784 and ILL 6778 were less than 1, a suggested minimum level for normal functioning of many metabolic processes in plants. The present study shows that salt tolerance observed previously at the early growth stages is conferred at the adult stage in most of the accessions of lentil examined here; but for others in which no positive correlation was observed between different growth stages suggests that a combination of certain characters can be used as selection criterion for improving salinity tolerance in lentil through exploitation of inter- and intra-cultivar/line variation.