Molecular and phenotypic characterization of interspecific Prunus salicina Lindl. × Prunus armeniaca L. (plumcot) hybrids

A Japanese plum (Prunus salicina Lindl.) breeding program coordinated by CEBAS-CSIC and IMIDA is being conducted since 2011 in Murcia (Southeast of Spain). Self-compatibility and resistance to sharka disease (Plum pox virus, PPV) are some of the main objetives for the new released cultivars. For that purpose and due to the lack of sharka resistance in Japanese plum species, numerous interspecific crosses between Japanese plum (Prunus salicina Lindl.) cultivars and self compatible, sharka-resistant apricot (Prunus armeniaca L.) cultivars have been performed during these years in order to obtain resistant and self-compatible plumcots (interspecific hybrids). In addition, these new plumcots are characterized by a new fruit typology with a great agronomic and market potential. In this work, the most important agronomical and phenotypic traits have been evaluated in these interspecific hybrids. An initial screening of more than 650 seedlings was carried out for interspecific hybrid verification using SSR (simple sequence repeat) markers. S-allele genotyping and PPV resistance evaluation in controlled conditions were performed in the true interspecific genotypes. In addition, a complete phenotypic characterization was performed including pollen viability, androsterility, leaf and fruit morphology, flowering time, flowering intensity, flower color, pubescence of ovary, ripening date, pubescence of fruit skin, productivity, fruit color, flesh color, firmness and organoleptic characteristics such as soluble solids content and acidity.