Texture and other fruit quality parameters profiling for sweet cherry and berries breeding

Breeding for berries quality, and in particular for highly subjective goals like texture, secondary metabolites and flavour is challenging. Moreover, breeding both for texture and aroma has occurred mainly without assisted methodologies but mostly by subjective chance, in particular in early selection phases. The aim of this work was to obtain high-throughput quality profiles of different berries with regard to a complex and commercially important quality trait like texture. For the different crops, a similar experimental design was applied. The first aim of the different experiments was to unravel the widest variability for the different traits of interest to determine fruit quality within the respective germplasm. The second aim was to proof the differences present at the two cardinal time-points for the production and commercial pipeline: at harvest and after storage. More precisely storage conditions were: 2°C and relative humidity of 85-95% for six weeks at normal atmosphere conditions for blueberry, 8 days for strawberry, 3 and 7 for raspberry and 7-14 days for cherry, in order to monitor the dynamics of the different quality traits for each genotype. Principal component analysis based on fruit textural proprieties, allowed for blueberry a distinct separation of the 46 Vaccinium cultivars evaluated, revealed a clear separation of the four harvest ripening stages. As expected, storage also highlighted textural differences among cultivars that were magnified compared to ripening. The effect of ripening stage and genetic differences on the blueberry texture profiles and other fruit quality related traits were significantly high. The development of the texture raspberry methodology is highly related to fruit anatomy, which is more complex in raspberry than in the other berries. A parallel approach of penetration and compression on a double bite cycle measurements was thus chosen. A high variation was explained among 29 raspberry cultivars tested in this study. Differences among genotypes were observed at all ripening stages, showing a significant cultivar dependent pattern at harvest and after storage. The two methodologies allowed to complimentary profile raspberry texture and a clear relationship among 22 texture mechanical parameters and morphological quality traits was elucidated. For strawberry, the texture profiling was done on a double cycle production for different genotypes, both including in the experimental setting junebearing and everbearing. 87 genotypes were profiled at harvest and post-harvest. The strawberry texture variation in the genetic pool analysed was explained by changes of different parameters. The development of the fruit was also investigated for texture, morphological and metabolic traits. The results demonstrated the potential of using species specific methodologies towards the comprehensive study of strawberry fruit quality attributes during harvest and storage. The texture trait of sweet cherry (Prunus avium L.) was investigated on 36 cultivars. Changes in texture were investigated at harvest, after storage and the effect of the year and the rootstock were evaluated. Significant genotypic variation is present in the genepool for texture. The identification of a storage index specifically designed for cherry, based on the texture parameters developed, allows clustering at maturity and after storage the most suitable genotypes for storage attitude or postharvest use. The texture variability ascertained and association with other quality-related traits in the three berries and in cherry with this research shows that it is underexploited for its use in breeding, thus giving room for future improvements, increasing the chance not only to accelerate progress in selection processes for these novel traits through an appropriate identification and use of them as biomarkers but also allowing a much more focused and assisted process throughout the all industry chain, as for sorting and product segmentation.