Effect of genotype and season on gynogenesis efficiency in Gerbera

The effects of season, genotype and their interaction on haploid production were evaluated on four genotypes responsive to gynogenesis. Naked mature u nfertilised ovules, collected from April to October, were cultivated on mod ified MS basal medium plus 0.88 mu M 6-benzyladenine and 0.57 mu M indol-3- acetic acid. After 30-60 days, recovered calli were transferred to a MS bas al medium with 8.8 mu M BA and 0.57 mu M IAA for regeneration. Genotype and season of ovule collection substantially interact in the recovery of haplo id calli. Between the four genotypes analysed, two gave more calli in the s pring, one in the autumn and the fourth showed only weak differences betwee n seasons. Shoot recovery depended upon both the season of ovule collection and the genotype but no significant interaction was shown by our data. The ability to produce haploid callus is not predictive for efficient shoot re generation.