Identification and Parentage Analysis of Citrus Cultivars Developed in Japan by CAPS Markers

To protect the rights of breeders of the major citrus cultivars developed under breeding programs by the national institute of Japan, we developed a method of cultivar identification based on cleaved amplified polymorphic sequence (CAPS) markers, and used it to evaluate their identity and parentage. We selected 19 CAPS markers that had a single-locus origin and moderate polymorphism, and used them to construct genotyping data for 59 citrus cultivars (including American accessions), local varieties, and selections. Of the 19 CAPS markers, 8 were sufficient to discriminate among all accessions except 'Mato' buntan (Citrus grandis Osbeck) and 'Hirado' buntan (Citrus grandis Osbeck). Among the 33 Japanese cultivars, the parentage of 30 agreed with that reported, but 'Setoka', 'Southern Red', and 'Reikou' had discrepancies at one or more loci. Using 15 to 18 CAPS markers to validate the putative parentage revealed that the seed parent of 'Setoka' was 'KyEn No. 4', not 'Tsunonozomi', and the pollen parent of 'Southern Red' was 'Osceola', not ponkan (C. reticulate Blanco). The seed parent of 'Reikou' remains unknown.