J. ENCHEVA, M. CHRISTOV and P. IVANOV
Dobroudja Agricultural Institute, BG - 9520 General Toshevo, Bulgaria
ENCHEVA, J., M. CHRISTOV and P. IVANOV, 2004. Developing of B lines in sunflower (Helianthus annuus L.) by combined use of polycross method with ultra sound and embryo culture method. Bulg. J. Agric. Sci., 10: 281-290
As a result from the polycross method between Bulgarian sunflower B line 1607 (line with normal cytoplasm, sterilized by GA3) and mixed pollen from six B lines (lines with normal cytoplasm) with known genetic composition, and treatment of immature hybrid embryos with ultra sound, a large number of new B lines were developed. To shorten the breeding process, the method of embryo culture was used. Five generations were obtained within one calendar year through it. Lines 15, 19, 24, 25, 47, 52, 56, 57, 58 and 63, subjected to investigation in this study, are characterized by significant changes concerning most of the studied characters. The changed morphology of the lines and the very good combining ability in hybridization are the desired combination in the breeding programme of sunflower. Hybrids 67, 71, 77, 79, 80, 81 and 82 developed with the participation of lines mention above possess higher seed and oil yield and shorter vegetation period than the mean standard (the Bulgarian commercial hybrids Albena and Super Start). Due to the good combining ability in hybridization, sterile analogues were developed to the 5 of the new B lines (24, 52, 56, 57 and 58). The combined use of polycross method with ultra sound and 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.