Inheritance of Salt Tolerance as Measured via Root Length in Spring Wheat (Triticum aestivum L.) Under Different Salinity Levels

A 6 x 6 diallel cross among three sensitive (18180-II, 18205-I, 18205-I and DN-18) and three tolerant (18194-II, DN-4, and LU-26S) wheat genotypes were analyzed. Thirty-six genotypes were sown in a completely randomized design in hydroponic culture. Data for root length was recorded in three salinity levels, that is., control, 10 and 15 d Sm-1. Additive gene effected controller tolerance in the two salinity levels (10 and 15 dSm(-1)). Dominance effects were highly significant under all three treatments. Variance components indicated dominance effects to be more important than additive effects for root length. The distribution of varietal points along the regression line indicated that the root length LU-26S, 18180-II and DN-18 possessed the highest number of dominant genes, and 18205-I, 18194-II and DN 4 carried the largest number of recessive genes. (C) 2006 by The Haworth Press, Inc. All rights reserved.