ChileanJAR

Salinity reduces germination, delays emergence, and inhibits seedling growth of linseed (Linum usitatissimum L.) while some varieties are less affected by salinity than others. In this study, we aimed to determine the effects of NaCl levels (0, 5, 10, 20 and 30 dS m^-1) on germination and seedling growth of 10 linseed genotypes (lines 87, 89, 104, 114, 193, 194, 209, 215, C-90 and cv. Sarý-85) and to classify the genotypes for salinity tolerance using germination and seedling characteristics. Germination percentage, mean germination time, root and shoot length, seedling fresh and dry weight, Na⁺ content and Na:K ratio of seedlings were investigated. Classification of linseed genotypes for salinity tolerance was done according to (i) combination of Principal Component and Cluster Analysis, (ii) Na⁺ content, and (iii) Na:K ratio of seedling. The results showed that the highest values were obtained from lines 193, 194 and 215 except for mean germination time, while germination percentage was not adversely influenced by NaCl up to 20 dS m^-1. Seedling growth was inhibited at 20 dS m^-1 although genotypes exhibited varying responses. Na⁺ content was enhanced by NaCl, but seedling from lines 194, 193 and 215 had the lowest Na⁺ content at all NaCl levels. Cluster analysis performed by multiple parameters revealed three groups for salinity tolerance. It was concluded that lines 193, 194, and 215 were tolerant, lines 87, 209, C-90, and cv. Sarý-85 were moderately tolerant and lines 89, 104, and 114 were salt-sensitive genotypes. Classification of genotypes for Na⁺ content and Na:K ratio showed similar result for tolerant genotypes while different genotypes for sensitive group were detected.