Pedicel-fruit retention force in sweet cherry (Prunus avium L.) varies with genotype and year

Abstract

Sweet cherry is one of the most labor-intensive fruit crops due to the small fruit size, large tree structure, and need to harvest the fruit manually. To enable adoption of mechanical or mechanical-assisted harvest, it is necessary to develop sweet cherries with low retention force between pedicel and fruit. Many commercial sweet cherry cultivars and F1 seedlings were assessed for pedicel-fruit retention force (PFRF) and fruit quality attributes in 2009, 2010 and 2011. PFRF in sweet cherry cultivars and F1 seedlings displayed continuous distribution, suggesting that PFRF is a quantitative trait. The effects of genotype and year were significant as well as the interaction between genotype and year (G×Y) (p<0.0001). The significant G×Y highlights the importance of both genetics and environment on PFRF. The significantly lower (p<0.0001) mean PFRF of F1 seedlings (561±234g in 2009 and 884±281g in 2010) compared to their parents and/or commercial cultivars (814±295g in 2009 and 1029±311g in 2010) suggests that PFRF can be reduced through breeding. Correlations between PFRF and fruit quality attributes were generally low (correlation coefficients of −0.12 to 0.10), suggesting that it will be possible to combine low PFRF and excellent fruit traits through strategic hybridization.