Characterization of fertile homozygous genotypes from anther culture in apple

Abstract

Doubled haploids can improve the efficiency of breeding and genetic study in apple (Malus × domestica Borkh.). Seventeen homozygous genotypes were obtained by in vitro anther culture from 'Senshu' apple. Flow cytometry analysis revealed that the ploidy level of the anther-derived plantlets was diploid. Simple sequence repeat (SSR) analysis determined the origin and homozygous status of the anther-derived plantlets. The results of S-RNase polymerase chain reaction (PCR)-digestion analysis reinforced the homozygous state. The morphological characteristics and reproductive potential of the doubled haploids were investigated. It is especially interesting that one of the doubled haploids derived from anther culture had fertile pollen grains (rate of in vitro germination was 20.6%-33.0%), and several progenies were obtained from the cross between 'Prima' apple and the doubled haploid. The hybridism of these seedlings was confirmed by SSR analysis. Furthermore, the female gametes of the doubled haploid showed slight fertility. Thus, this doubled haploid will be valuable for breeding and genetic studies.