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Phenotypic analysis of texture traits was performed in an apple progeny by three complementary approaches: two classical instrumental measurements (compression and penetrometry), sensory assessment and histological screening. The progeny was composed of 141 individuals harvested over 2 years. Sensory and instrumental texture were assessed at harvest and after 2 and 4 months of cold storage. Histological screening was performed by combining macro-vision of outer parenchyma sections and image analysis on fruits after 2 months storage. Harvest year was observed to have a major impact on texture phenotypes followed by storage and genetic factors. Principal component analysis of data from the instrumental texture evaluations showed that the two methods complemented each other in characterizing the texture of the apple progeny. Compression parameters correlated better than penetrometry variables with sensory descriptors related to crispness, firmness, and graininess. Cell size distribution differentiated individuals in the apple progeny. It correlated with instrumental texture analyses and with juiciness perception. All measured texture related traits showed that they were all under genetic control with high heritability values. Higher values were obtained for fruits after 2 months storage. These results provide ground for future search of new apple texture QTLs

Postharvest texture change is a fundamental question for fruit growers and breeders as it drives consumer acceptability. To decipher the genetic control of fruit texture, we studied an apple segregating population over 2 years at harvest and after 2 months of cold storage. Texture complexity was dissected in quantitative traits, related to (i) sensory perception of fruit quality and (ii) fruit mechanical properties. Genetic models including storage, genotype and their interaction effects were built. After selection of a model, broad sense heritabilities were estimated. Strong genetic and storage effects were identified for all texture traits with significant interaction. Moreover, the structure of traits co-variations was preserved after storage. Based on the new integrated genetic map, numerous quantitative trait loci (QTLs) were detected, revealing multigenic control of fruit texture traits. QTLs were clustered according to the kind of texture assessment i.e. penetrometry, compression and sensory. Moreover, QTL stability over years and storage periods was investigated. Lastly, a short list of relevant texture traits, such as fruit global hardness and fruit deformation until skin failure, is proposed to optimize texture phenotyping for future quantitative genetic studies