Preliminary screening of domestic barley and wild barley genotypes for salt tolerance

Salinity is a critical challenge facing productivity of barley around the world, necessitating the development of salinity tolerant varieties. Screening genotypes of two barley species during germination and seedling growth stages was conducted to identify genotypes with superior performance under saline stress conditions. Five genotypes of domestic barley (Hordeum vulgare L.) and six of wild barley (H. bulbosum) were used in this study. Genotypes were germinated in solutions of 0, 1.0, 1.5, and 2.0% NaCl (0, 171, 257, and 342 mM NaCl). Shoot and root length were recorded 10 d after germination. Upon reaching the three-leaf stage, seedlings were irrigated with 500 mM NaCl solution for 3 wk to evaluate salt tolerance using the growth index. The analysis of variance showed there was a high genetic variation among genotypes. Only genotypes PI220054, PI227242, and PI420909 of wild barley species germinated at the 2% NaCl salinity level. All domestic barley genotypes failed to germinate at 2% NaCl salinity and showed reduction of root and shoot length greater than wild barley genotypes under saline conditions. Mean root and shoot lengths decreased as the level of NaCl increased for all genotypes. This condition was more intense in domestic than wild barley genotypes. Seedling screening showed PI268243 had the greatest growth index compared with the other genotypes. The PI227242 genotype had the greatest growth index among wild barley genotypes. Regression analysis indicated that there was no relationship between salt tolerance at germination and seedling growth stages.