Effect of Gamma Irradiation for Induction of Gynogenesis in Cucumber (Cucumis sativus L.)

Institute of Horticulture and Canned Foods, BG-4002 Plovdiv, Bulgaria


NIKOLOVA, V, V. RODEVA, M. ALEXANDROVA and V. STOEVA, 2001. Effect of gamma irradiation for induction of gynogenesis in cucumber (Cucumis sativus L.). Bulg. J. Agric. Sci., 7: 415-420

Haploid induction by gynogenesis, followed by chromosome doubling, gives an opportunity for creation of homozygous genotypes, from heterozygous parents within only one generation. The inclusion of isogenic lines in the heterosis breeding leads to fast obtaining of F1 hybrids.
The only one of the published methods about haploid plant regeneration in Cucurbitaceae family employs pollination with γ (Co60) rays irradiated pollen. The parthenogenetic development of embryos must be followed by embryo rescue and in vitro cultivation.
In results of our investigations for induction of gynogenesis were established the suitable cucumber genotypes (T19 and S.R. PI 8360) as mother and father components, optimal doses of gamma rays for pollen irradiation (0.3 and 0.5 KGy), some specific peculiarities in development (slower growth and development) and morphology of haploid plants (specific leaves and flowers smaller is size with strongly cut petals), disturbances in microsporogenesis which determine a complete sterility.
For precise proof of haploid genome (n = x = 7) and selection of haploid plants the chromosome number was counted and were used cytological "markers"-number and type of sporads, pollen morphology and sterility.

Key words: gynogenesis, irradiated pollen, haploid, sterility