S-RNasegenotypes of apple (MalusdomesticaBorkh.) including new cultivars, lineages, and triploid progenies

SummaryWe have determined the S-RNase genotypes of 33 new apple cultivars and lineages produced in Japan, 44 unknown cultivars and two lineages, and 22 triploid progenies. We have speculated on the putative parentage of new cultivars and lineages based on their S-RNase genotypes and also identified mistaken parents. In the case of the triploid progenies, the breeding of new cultivars using a triploid paternal parent may pose problems due to its low pollen viability. Nevertheless, diploid and triploid progenies were obtained using a triploid maternal parent. We have compiled a database of 516 apple S-RNase genotypes, including those previously investigated, which included a survey system for cultivar combinations, showing those that were fully-incompatible, semi-compatible, or fully-compatible, together with information on the PCR-RFLP method used for the identification of S-RNase genotypes and S-RNase allele designation (available at http://www.agr.nagoya-u.ac.jp/~0hort/apple/).