J. ENCHEVA, M. CHRISTOV, N. NENOV, P. IVANOV and V. ENCHEVA
Dobroudja Agricultural Institute, BG-9520 General Toshevo, Bulgaria
ENCHEVA, J., M. CHRISTOV, N. NENOV, P. IVANOV and V. ENCHEVA, 2003. Genetic variability of sunflower (Helianthus annuus L.) created by combination of polycross hybridization and ultrasonic or gamma radiation. Bulg. J. Agric. Sci., 9: 321–327
As a result from hybridization between the Bulgarian fertility restorer line R 763 and mixed pollen from a polycross population of known genetic composition, and treatment of immature embryos with gamma radiation or ultrasonic, a large number of new fertility restorer lines were developed. Lines R153 and R154, subjected to investigation in this study, are characterized by significant changes concerning most of the studied characters. The increased oil content in lines R153 and R154, the 100 % restoration ability and the very good combining ability in hybridization are the desired combination in the breeding programme of sunflower. Hybrid 99 and hybrid 100 developed with the participation of lines R153 and R154 considerably exceeded the mean standard (the Bulgarian commercial hybrids Albena and Super Start) by seed and oil yield. The combined use of interlinear hybridization with physical mutagenesis or ultrasonic and the embryo culture method leads to increased genetic variability in sunflower and to a considerable shortening of the breeding process, obtaining 5 generations within a single year.