Approaching the Dominant Dwarfing Gene Ddw1 in Rye by Comparative Genetics

Rye (Secale cereale L.) is a major crop in Russia, Poland and Germany with versatile uses for human and animal nutrition and as a substrate for bioenergy production. Rye breeding aims to develop new high yielding varieties which are, in view of the global climate change, more robust and less demanding in water and fertilizer. These efforts are directed to enhance the sustainability of rye production and to keep rye competitive in modern agricultural production systems.

Lodging resistance ranks among the major breeding goals in rye. Improved lodging resistance will reduce the currently required application of growth regulators and, thus, increase the efficiency of rye production. The main approach to overcome lodging is a reduction of plant height by exploiting dwarfing mutants. In wheat and rice, the alteration of plant height by recessive dwarfing genes resulted in a significant increase of crop yield. In rye, particularly the dominant dwarfing gene Ddw1 has been used in Eastern European breeding programs to improve lodging in population varieties. The potential of Ddw1 for breeding highly productive hybrid rye varieties has yet not been elucidated. The implementation of Ddw1 in the development of homozygous dwarf inbred lines is hampered, as an efficient and reliable method to distinguish homo- and heterozygous dwarf genotypes is yet not available. In this study, we are approaching the long arm of rye chromosome 5R by comparative genetics to develop molecular markers for Ddw1. Results will be presented on mapping novel conserved orthologous set (COS) markers relative to Ddw1.