POLLINATION WITH GAMMA-IRRADIATED POLLEN AND DEVELOPMENT OF FRUITS, SEEDS AND PARTHENOGENETIC PLANTS IN APPLE

Four apple (Malus X domestica) genotypes, Erovan, Golden Delicious, R1-49 and X6677, were pollinated with a marked pollen irradiated by gamma-rays at doses ranging from 125 to 1000 Gy. Pollination with such irradiated pollen affected fruit set, seed number and seed contents, and induced the formation of parthenocarpic fruits and the development of parthenogenetic embryos. The immature embryos extracted from seeds, 2 and 3 months after pollination, were cultured in vitro and germinated after 2 months of cold treatment (3-degrees-C). Haploid plants were obtained in all 4 genotypes, after pollination with pollen irradiated at doses from 200 to 500 Gy. The optimum conditions for induction of apple haploids, by irradiated pollen approach, have been established.