Inheritance studies of metric traits in three barley populations under normal and saline-alkali soils

The weighted least square estimates of gene effects (Hayman 1958) were estimated using 7 generations of the cross 'BG 25'×'NP 21' and 'BH 15'× 'RD 103', and 11 generations of the cross 'C 164'× 'EB 1556'. The joint scaling test of Cavalli (1952) indicated the failure of a simple additive - dominance model in majority of the cases. The variability of the characters studied could not be explained by the 6- parameter model in cross 'C 164'×'EB 1556', but it could explain the majority of characters in the crosses 'BG 25'×'NP 21' and 'BH 15'×'RD 103'. The grains per ear in 'BG 25'×'NP 21' exhibited differential response of generation means to a change in the environment due, perhaps. to the more pronounced expression of additive gene action in saline-alkali soil. Among the components of epistasis, additive X additive and dominance X dominance types of epistasis were important in 'BG 25'×'NP 21', while dominance X dominance type of epistasis was important in the crosses 'C 164'× 'EB 1556' and 'BH 15'×'RD 103'. The cross 'BH 15'× 'RD 103' appeared to be the least sensitive to a salinealkali soil condition.