Anther culture in apple

Homozygous genotypes of apple were induced by anther culture to improve breeding efficiency. The rate of embryo production was very low, although the effective induction of microspore divisions was much higher. Differences in embryo yield among cultivars and with duration of cold treatment were found. There seemed to be no relation between callus and embryo production. Shoots were obtained by dedifferentiation of the embryos followed by organogenesis. Shoot regeneration and multiplication depended on the genotype. As rooting and subsequent acclimatization was very difficult, micrografting became the alternative procedure to establish plants ex vitro. Most plants were diploid or triploid; a small proportion of the plants was haploid or tetraploid. Irrespective of their ploidy level, ail fertile plants can be useful in breeding programmes as they are all homozygous. The homozygous nature of the plants was proved by analysis of the Incompatibility gene S which is normally heterozygous.