Genetic identification of apple cultivars bred in Korea using simple sequence repeat markers

Among the many DNA markers currently available, simple sequence repeat (SSR) markers are well developed and widely used for gene identification and cultivar discrimination by apple breeders and researchers. We developed SSR fingerprints for identification and to reveal the genetic diversity of 22 apple cultivars released from Korea. We used a total of 22 SSR markers. Among them, 15 SSR markers were developed from the complete sequence of ‘Golden Delicious’ and 7 SSR markers were chosen from the HiDRAS database. Except for somatic mutants, cultivar identification of all Korean bred apple genotypes was accomplished by using only two SSR markers (CH03d07 and KFBG-7). Parent-offspring relationships analysis was performed to investigate the real parents of three suspicious cultivars (‘Gamhong’, ‘Hongan’, and ‘Green Ball’). Based on the SSR markers experiment and reported S-RNase allele, we confirmed that ‘Fuji’ was used as paternal parent of ‘Gamhong’ and either ‘Hongro’ or ‘Natumidori’ were used as paternal parent of ‘Hongan’. Moreover, ‘Jonathan’ rather than ‘Fuji’ seems to be a paternal parent of ‘Green Ball’.