Cell wall modifications lead to cultivar differences in apple (Malus domestica) fruit mealiness

Recently, four quantitative trait loci linked to flesh mealiness in apples were identified, with one associated the MdPG1 allele. Hence, this study analyzed cell wall changes two mealy (Orin and Akane) three non-mealy (Kiou, Kitaro, Fuji) apple cultivars during ripening. The fruits harvested for each cultivar at optimum maturity stored 20°C 20 days. firmness of ‘Kitaro’ ‘Fuji’ fruit did not change strikingly over days, whereas that other cultivars, especially ‘Akane’ ‘Orin’, gradually decreased Between a texture, produced extremely low levels ethylene, ‘Orin’ high levels. water-soluble polyuronide (WSP) contents ‘Kiou’ clearly. In contrast, WSP increased ‘Kiou’, ‘Kitaro’, fruit, molecular-mass distributions WSPs Conversely, distribution exhibited downshifts These results indicate solubilization depolymerization pectic polyuronides occur ripening ethylene may be involved these changes.