Effects of the Rht8c, Rht-B1b, Rht-B1e and Rht-D1b genes on the plant height of wheat have been investigated. Variations of these effects are significantly modified by genetic background and year conditions. Complex of the alleles Rht8c Rht-B1a Rht-D1b Ppd-D1a is advantageous for the conditions of the South Ukraine region. There are gene(s) in the genotypes of some varieties which significantly decrease height and are unidentified by molecular markers in our investigation.