V. Bozhanova, D. Dechev

The osmoregulation is one of the most important cell adaptation mechanisms occurred at beginning of drought. The inheritance of osmoregulation ability in durum wheat by using indirect method for trait measuring was studied. Five durum wheat genotypes with different level of tolerance to osmotic stress were included in diallel crossing scheme. Among the parents genotypes the old Bulgarian cultivar A-223 distinguishes with the lowest seedlings growth depression coeficient of 32,5 %, i.e. with best ability of osmotic regulation. The lowest osmotic regulation ability shows cultivar Gergana. The hybrid combinations including the most tolerant parent A-223 show the lowest coeficient of depression among the F hybrids. The conducted dialel analyses shows 1 the high significance of the effects of the general (GCA) and specific combinative ability (SCA) during the all 3 years of the investigation. The inheritance of high levels of osmoregulation is determinted by both the aditive and non-aditive gene effects. The non-aditive gene efects (SCA) strongly predominate over the aditive and have a significant role in the observed big heterozis effect. The significance of variances of both GCA and SCA requires the selection of single plants by investigated traits to be shifted in the later segregating progenies.