Gibberellin-sensitive dwarfing gene Ddw1 has no negative effect on the root system of field-grown winter rye

Abstract

Rye is a small-grain cereal with an extensive and well-branched root system that is particularly suitable for grain production in marginal environments where other grain cereals, especially wheat, cannot thrive well. However, no significant genetic gain could be achieved to improve plant height and lodging resistance in the last 30 years in rye. Thus, the relatively low grain-to-straw ratio currently hinders rye from becoming more integrated into cereal crop rotations. Here, we report first results on the effects of the gibberellin-sensitive dwarfing gene Ddw1 on the root system and aboveground traits of rye under field conditions. We assessed root traits of semidwarf and tall genotypes in two field environments at the time of anthesis using soil coring, the core-break method and root scans. Semidwarfs revealed no negative but slightly positive effects on rooting depth, total root length, root length density, and cumulative root length distribution. While plant height was significantly reduced, no increase in harvest index and grain yield was observed in semidwarf prototypes. We conclude that rye does not lose the advantages of its deep and widely branched root system with the introgression of Ddw1, especially not on marginal sites.