BREEDING TOMATOES FOR SALT TOLERANCE - FIELD-EVALUATION OF LYCOPERSICON GERMPLASM FOR YIELD AND DRY-MATTER PRODUCTION

Salt tolerance of 59 cultigens of tomato (Lycopersicon esculentum Mill.), seven wild Lycopersicon accessions (acc.), and one interspecific hybrid was studied under arid field conditions. Evaluation of salt tolerance was based on relative total dry matter (RD) and relative total yield (RY), calculated as the ratio between performances of saline-treated and control plants. The tomato cultigens were irrigated with water having electrical conductivities (ECi) of 1.5 (control), 5, 10, or 15 dS.m-1. Considerable variation in salt tolerance was found among the cultigens, but at 15 dS.m-1 all showed reduced RD and RY (< 0.6). The cultivar M82-1-8 (M82), one accession of L. cheesmanii (Lc), three accessions of L. pennellii (Lpen), three of L. peruvianum (Lper), and an interspecific F, hybrid (M82 X Lpen acc. LA-716) were examined for RD at three salinity levels, ECi = 1.5, 10, and 20 dS.m-1, in three annual trials. The salt tolerance of Lpen and Lper were higher than those of M82 and Lc; the interspecific F1 was the most tolerant and was usually unaffected by even the highest salinity level. The results of this study indicate the existence of a genetic potential for high salt tolerance in wild Lycopersicon germplasm.