INQUIRING FOR A CHANCE TO OBTAIN STRAWBERRY (FRAGARIA-X-ANANASSA DUCH) DIHAPLOIDS

The possibility of dihaploid development from tetrahaploid anthers in strawberry has been tested in culture. From the total number of 4635 a nthers taken from 57 tetrahaploid plants (secondary cycle of anther cu lture) and 4042 anthers from 7 octoploid varieties - 119 plants were o btained. The success depended on the growing conditions of donor plant s (field conditions appeared better) and plant genotypes (tetrahaploid s previously regenerated in vitro were better donors). The majority of plants regenerated from tetrahaploid anther callus (54.6%) were mixop loids. The remaining plants were polyploids from 2n=4x=28 to 2n=8x=56. Only 3 mixoploid individuals had lower than 2n=4x=28 number of chromo somes. Plants regenerated from anther callus were capable of developin g seeds and fruits. Seed germination was rather low and fruit yield va ried. Still, it was possible to select a group of 12 plants, possibly of somaclonal origin, fit for further breeding.