Rye has important genes for biotic and abiotic stress resistance. Introduction of these genes to wheat by breeding wheat-rye translocation have been intensively used in wheat breeding program. Rye chromatin 1RS and/or 2RL show superior performance in unfavorable environments. In order to develop high yielding wheat, we applied various molecular breeding strategies. To develop EST-derived 1RS specific markers, we used comparative genomics with public sequence databases of Poaceae family. Putative rye chromatin specific sequences were used to design 1RS specific markers. To identify genes related to water deficiency, cDNA AFLP analysis was used in PEG treated seedlings of 1RS RILs. For functional analysis of identified genes and markers, we used Brachypodium distachyon, as a new model plant of temperate grasses. B. distachyon were recently applied for transformation and we constructed Agrobacterium-mediated transformation system. Integration of those strategies and conventional breeding method would enhance the usefulness of rye chromatins for wheat improvement.
The direct use of mutation is a valuable approach to generate variability in crops. The electron beam, one of the ionizing radiations, has been applied to evaluate its effect on seed germination and early seedling growth of creeping bentgrass (Agrostis palustris Huds., cv Penn-A1). The mature dry seeds were irradiated with various electron beam energies (0.3, 1.0, 1.3, and 2 MeV) and current levels (0.03 and 0.06 mA). Although large variability was existed within each dose, distinct difference of germiability and seedling vigor were not found at 0.3 MeV / 0.03 mA and 0.3 MeV / 0.06 mA beam condition. However, 1.0 MeV / 0.06 mA application most effectively inhibited and retarded seed germination and most severely restricted cotyledon and root growth in early seedling growth. The direct use of electron beam would be a valuable supplementary approach to generate mutants suitable for breeding purposes.