Effect of Gamma Irradiation on Fertility Restorer Sunflower Lines (Helianthus annuus L.) and Their Regeneration through Direct Organogenesis and Somatic Embryogenesis

J. ENCHEVA and M. DRUMEVA
Dobroudja Agricultural Institute, BG-9520 General Toshevo, Bulgaria

Abstract

ENCHEVA, J. and M. DRUMEVA, 2005. Effect of gamma irradiation on fertility restorer sunflower lines (Helianthus annuus L.) and their regeneration through direct organogenesis and somatic embryogenesis. Bulg. J. Agric. Sci., 11: 437-443

The aim of this investigation was to follow the genotype response of five fertility restorer lines to in vitro cultivation of immature zygotic embryos using the method of direct organogenesis and somatic embryogenesis, as well as to study the effect of gamma- radiation at doses 2.5 Gy, 5 Gy, 7.5 Gy, 10 Gy, 12.5 Gy, 15 Gy, 17.5 Gy, 20 Gy, 22.5 Gy and 25.0 Gy on the increasing of regeneration response. A difference was observed in the genotype response both of the check variant and the variants with gamma irradiation with respect to in vitro regeneration. The highest regeneration potential under controlled conditions was demonstrated by line K-821, and lowest - by 2128 R. Line 147 R was most sensitive to the effect of gamma-radiation. Doses 5 Gy and 10 Gy proved most efficient for regeneration stimulationin genotypes 147 R and 1028 R. Lack of regeneration was registered in all investigated genotypes at dose 25 Gy, which was therefore considered terminal.

Key words: sunflower, direct organogenesis and somatic embryogenesis, gamma irradiation, fertility restorer lines