ORIGINAL PAPER Transmission of Fruit Quality Traits in Apricot (Prunus armeniaca L.) and Analysis of Linked Quantitative Trait Loci (QTLs) Using Simple Sequence Repeat (SSR) Markers Juan Alfonso Salazar & David Ruiz & José Egea & Pedro Martínez-Gómez # Springer Science+Business Media New York 2013 Abstract Twelve important pomological traits related to fruit quality were studied during 3 years in an F 1 apricot progeny of 160 seedlings derived from a cross between the Spanish selection ‘Z701-1’ and the South African cultivar ‘Palsteyn’. Results indicated quantitative transmission of most of the fruit quality traits studied. In addition, a clear influence of the genetic background of parents was observed. In some seed- lings, values outside the range of the parent were observed due to the influence of this genetic background. No correlations were found among most agronomic traits in apricot during the 3 years of the study. However, high correlations between years were described for most of the evaluated traits, and the envi- ronment had limited influence on the expression of the trait. A genetic map was developed using 41 apricot and peach SSR markers. The map obtained showed eight linkage groups (corresponding to the eight chromosomes) covering a total distance of 369.3 cM and an average distance between markers of 9 cM. Fifty-four QTLs associated with different traits were identified, including: blooming date (linkage groups G1, G4 and G7); ripening time (G4 and G6); fruit development (G4 and G6); fruit weight (G1 and G4); stone weight (G1 and G7); flesh color (G1 and G6); pH (G1, G2 and G4); malic acid (G1, G2 and G4); and soluble solids content (G4 and G5). We have highlighted several QTLs in G4 that explain the variability in various traits related to fruit quality such as blooming date, ripening time, and soluble solids content. In addition, we have also highlighted an important QTL on G2 that explains much of the variation in levels of acidity. Keywords Apricot . Fruit quality . Inheritance . Correlations . Microsatellites . QTL . Marker-assisted selection Introduction Apricot (Prunus armeniaca L.) is one of the most important and desirable of the temperate tree fruits, with total world production reaching around 3.83 million tons in 2011 (http:// faostat.fao.org). Fruit quality is fundamental for the accep- tance of apricot cultivars by consumers, especially due to the current situation of high competition in the markets with the presence of numerous new cultivars and other fruits and foods. However, there has been an evolution in apricot fruit quality parameters in the last decades, such as an increase in fruit size and firmness as well as changes in the attractiveness of the blush color and the soluble solids content and titratable acidity (Tricon et al. 2009). Numerous pomological traits influence apricot fruit quality (Bailey and Hough 1975; Bassi and Selli 1990). Souty et al. (1990) proposed size, color, firmness, resistance to manipulation, taste, aroma, and texture as the fundamental quality attributes. In addition, sensorial properties in apricot fruits are mainly influenced by the sugar and organic acid content, volatile compound content, color, size, and firmness (Gurrieri et al. 2001). Significant genetic diversity has been observed in the apricot species with respect to some quality traits, which is fundamentally due to the different genetic origins of the cultivated apricot cultivars (Ledbetter et al. 1996; Badenes et al. 1998; Asma and Ozturk 2005; Ruiz and Egea 2008). Ruiz and Egea (2008) studied fruit quality attributes for two consecutive years in 43 apricot cultivars and selections grown in a Mediterranean Electronic supplementary material The online version of this article (doi:10.1007/s11105-013-0625-9) contains supplementary material, which is available to authorized users. J. A. Salazar : D. Ruiz : J. Egea : P. Martínez-Gómez (*) Department of Plant Breeding, CEBAS-CSIC, PO Box 164, 30100 Espinardo, Murcia, Spain e-mail: pmartinez@cebas.csic.es Plant Mol Biol Rep DOI 10.1007/s11105-013-0625-9