Development and application S-SAP molecular markers for the identification of apple (Malus × domestica Borkh.) sports

Abstract

SummaryApple (Malus _ domestica Borkh.) is a widely-cultivated, economically important fruit crop with nutritional and medicinal value. Apple has emerged as a model horticultural crop in the post-genomic era. Apple sport resources are important, develop gradually in the apple industry, and provide genetic diversity. In this study, we have successfully developed a sequence-specific amplification polymorphism (S-SAP) marker system based on Ty1-copia retrotransposons in the apple genome. Among the 34 primer combinations used to develop the S-SAP marker system, two primer combinations produced profiles with clear and different peak patterns. Based on these primer combinations, 15 apple sport accessions (four ‘Gala’, six ‘Fuji’, and five ‘Delicious’) were grouped into three clusters based on a genetic variation coefficient value of 0.78. In addition, 27 ‘Delicious’ apple sport accessions were also selected to perform S-SAP marker analysis using the same two primer combinations. The results showed that all ‘Delicious’ apple sport accessions tested were clearly distinguished. The S-SAP data shared many consistencies with known relationships among apple sport accessions. The available evidence showed that these S-SAP markers had a high level of polymorphism in these apple accessions, which could be applied efficiently to determine genetic diversity, systematic evolution, and for variety identification.