Inheritance of the ability for regeneration via somatic embryogenesis in Cyclamen persicum

Objective of the studies was to analyse the mode of inheritance of the regeneration ability of Cyclamen persicum via somatic embryogenesis. Three genotypes inbred to I differing concerning their in vitro response were self- and cross-pollinated to produce I-3, F-1 and F-2 progenies. These progenies were tested in vitro by culturing unpollinated ovules on callus induction medium containing 9.05 muM 2,4-D (2,4-dichlorophenoxyacetic acid) and 3.94 muM 2iP (6-(gamma,gamma-dimethylallylamino) purine) for two passages of 8 weeks each, followed by a period of 8 weeks on hormone-free medium for differentiation of somatic embryos. Regarding the regeneration ability, uniformity was confirmed in the I-3 and F-1 generation indicating the homozygosity of the parental I-2 plants. No differences between reciprocal cross combinations were found, so that maternal effects have been excluded. In the F-2 progenies, derived from crosses between the regenerating genotypes 3051 and 3738, respectively, and the non-regenerating genotype RS8, the segregation of plants with and without regeneration of somatic embryos fit to a 15: 1 ratio. Therefore, a genetic control of the regeneration ability by two dominant major genes with epistatic interaction was postulated. Regarding the regeneration rates, defined as the percentage of calluses with somatic embryos, and the regeneration intensity, as indicated by the number of somatic embryos per callus, a continuous variation between the plants with regeneration ability was noticed. These observations point to the fact that - apart from physiological and environmental influences - additional modifying genes might be involved.