Effects of Rht-B1b and Ddw1 Dwarfing Genes in Two Connecting Populations of Spring Triticale under Greenhouse Experiment Conditions

Abstract

Dwarfing genes not only reduce the height of triticale plants, but also have pleiotropic effects on important agronomic traits. An important task for breeding is to evaluate the effects of gibberellin responsive (GAR) and gibberellin-insensitive (GAI) dwarfing genes in one genotype. In the greenhouse experiment, we evaluated the effects of the GAI gene Rht-B1b of wheat and the GAR gene Ddw1 of rye on height and the main agronomic traits in two connecting populations derived from crossing Ddw1 donors (cv. ‘Mudrets’ and cv. ‘Valentin 90’) with a Rht-B1b donor (cv. ‘Dublet’). The results show a strong decrease in height under the influence of Ddw1 in both populations by more than 30%. In this case, Rht-B1b in the presence of Ddw1 does not lead to a significant decrease in the height of the spring triticale; thus, this is not likely to be included in breeding programs in order to further reduce the height in the presence of Ddw1 in the spring triticale germplasm. However, Ddw1 reduces the 1000 grain weight, while Rht-B1b increases the grain number per spike and grain number per spikelet. Thus, our studies have demonstrated the negative effect of Ddw1 on spring triticale productivity of the main spike in the greenhouse experiment, which can be partially compensated by Rht-B1b.