Diallel Analysis of Salt Tolerance at Germination and the Seedling Stage in Barley (Hordeum vulgare L.)

Diallel cross analysis for eight varieties of barley (Hordeum vulgare L.) differing in their salt tolerance at germination and at the seedling stage was performed. Salt tolerance at germination was evaluated from average shoot length after ten days of incubation in 250 mM NaCl solution. Salt tolerance at germination was mainly controlled by recessive genes. Non-allelic gene interaction was not observed. Non additive genetic variance was larger than additive genetic variance, and the mean degree of dominance was 1.47. The broad and narrow sense heritabilities were as high as 0.99 and 0.75, respectively. On the other side, a leaf injury index was used to assess tolerance at the seedling stage after exposure to 500 mM NaCl solution for four weeks. Salt tolerance at the seedling stage was predominantly controlled by additive genes, and the mean degree of dominance was 0.52. Non-allelic gene interaction was absent, and dominance was directed toward tolerance. Heritabilities were 0.85 and 0.75 in a broad and a narrow sense, respectively. No correlation was observed between salt tolerance at germination and the seedling stage in the 8×8 diallel tables. Thus the mode of inheritance for salt tolerance was different between germination and the seedling stage.