Flesh softening, particularly mealiness, which occurs in apples during storage, is an unfavorable characteristic as it decreases the commercial value of the produce. Although many studies have been conducted on firmness and texture at harvest as well as changes in them during storage, the degree of mealiness (i.e. loss of cellular adhesion) during storage has rarely been investigated. In the present study, we quantified flesh mealiness under 20°C with 85% relative humidity by measuring the degree of cell separation in flesh discs after 7 hours shaking in a sucrose solution. Samples were taken over a period of 2 years from 137 F1 individuals from a cross between ‘Orin’ x ‘Akane.’ QTL analysis revealed two QTLs for flesh mealiness on linkage group (LG) 10, and the genetic distance of these QTLs was approximately 35 cM. Md-PG1SSR10kd marker was the nearest to one of the QTLs with a LOD score of 5.13. This marker is located on 10 kbp downstream of the stop codon of MdPG1, known to be involved in firmness and texture of flesh. AF057134-SSR marker was the nearest to the other QTL with a LOD score of 5.30. The location of this marker is almost same as a QTL reported for flesh firmness at harvest and after cold storage for 2 months in ‘Mondial Gala’ apples. These results indicate that LG 10 has the significant importance in controlling not only fruit texture at harvest but also loss of texture during post-harvest storage.
