New Insights into Fruit Firmness and Weight Control in Sweet Cherry

Abstract

Fruit firmness and weight are among the most important fruit quality traits in fruit species. Understanding the control of fruit firmness and weight is essential for the development of domestication research approaches and for the implementation of new breeding strategies. A forward genetic study for these traits was performed using two F1 sweet cherry (Prunus avium) progenies derived from modern cultivars. Quantitative trait locus (QTL) analysis allowed the identification of genomic regions accounting for most of the phenotypic variation in both families. In addition, screening the Prunus persica genome v1.0 permitted the identification of putative candidate genes underlying the QTL with the major effect for fruit weight (LG5) and the one for firmness (LG6). A colocalization of QTLs and candidate genes was found in peach, apple, and tomato. These results give new insights of the interaction between fruit firmness and fruit weight and provide new cues for the identification of genes implicated in the control of these traits. The colocalization of genomic regions between progenies issued from modern cultivars and from modern cultivars × wild individuals suggests the absence of allele fixation within genes controlling fruit firmness and size, two traits potentially involved in domestication/diversification in sweet cherry.