CHLORIDE TOLERANCE IN SOYBEAN AND PERENNIAL GLYCINE ACCESSIONS

Diversity for chloride tolerance exists among accessions of perennial Glycine. Accessions whose tolerance thresholds exceed those of Glycine max cultivars may be useful germplasm resources. Soybean cultivars in cluding 'Jackson' (sensitive) and 'Lee' (tolerant) and 12 accessions o f perennial Glycine were evaluated for sodium chloride tolerance after 14 days in hydroponic culture at 0, 5, 10, and 15 g L-1 NaCl. Sodium chloride had adverse effects on the growth of G, max cultivars and per ennial Glycine accessions; however differential responses to salinity were observed among accessions. Considerably greater variation in sodi um chloride tolerance existed among the perennial Glycine accessions t han among the G, max: cultivars. Sodium chloride tolerance thresholds ranged from 3.0 to 17.5 g L-1 NaCl for the perennial accessions but on ly ranged from 5.2 to 8.0 g L-1 for the cultivars, based on a Weibull model of leaf chlorosis. All G, max cultivars were severely injured or killed by NaCl at 10 g L-1 and above. Five tolerant perennial Glycine accessions, G. argyrea 1626, G. clandestina 1388 and 1389, and G. mic rophylla 1143 and 1195, were significantly lower in leaf chlorosis sco re than any of the G, max cultivars at the 10 g L-1 NaCl treatment. Tw o accessions, G. argyrea 1626 and G. clandestina 1389 were able to tol erate 15 g L-1 NaCl with only moderate visual injury while all other a ccessions were severely injured or killed at this salt level. Variabil ity for chloride tolerance observed among the perennial Glycine access ions has potential utility for developing enhanced salt tolerance in s oybean.