Molecular analysis of genome instability in barley (Hordeum vulgare)

A reliable protocol for regenerating barley from seedling explants, including leaf bases with a complete apical meristem, has been developed at the Institute of Genetic Engineering. The system was established with Bulgarian barley cultivars (Ruen, Karnobat, Obzor and Yubilei) and reconstructed genotypes (K. Gecheff IG). Pretreatment of the mature embryos with a high concentration of 2.4D generated valuable and stable genetic deviations in the regenerants. The brewery cultivar Ruen was selected as the model genotype. It has been demonstrated that genetic variations, such as higher yield, earlier maturation and lower protein content, have been induced and maintained for 5 years. Comparative experiments, including treatment of barley mature seeds with 60Co gamma rays (10 and 20 krad) and sodium azide (1.10-3 M and 5 x 10-4 M), were also carried out. The results obtained showed that both treatments stimulated calusogenesis and regeneration of the plants. Molecular markers such as proteins, restriction fragment length polymorphisms (RFLPs) and random amplified polymorphic DNAs (RAPDs) were applied in studies on the mutagenic effects of 2.4D, gamma rays and sodium azide, and a combination threof, on the quality and quantity of the genetic diversification generated in tissue culture of the Bulgarian barley cultivars Ruen, Karnobat, Obzor and Yubilei and the reconstructed genotypes