Genetic relationships between red flesh and fruit quality traits in apple.

摘要

The genetic relationships between 'Type 1' red flesh and several fruit quality traits in apple were assessed in breeding populations that segregated in the field for white and red flesh. Transgenic plants grown in the glasshouse and genetically modified with the MdMYB10 gene, responsible for the 'Type 1' red flesh phenotype, were also examined. Moderate positive genetic correlations were found in each of two seedling populations between the amount of red colour estimated in the cortical flesh of fruit (WCI) and astringent taste and an internal flesh browning disorder (IFBD) observed in fruit after medium-term cold storage. In one family, a quantitative trait locus for astringent taste and IFBD was mapped to the same position at the bottom of linkage group (LG) 9 as that for WCI and MdMYB10. Fruit from 'Royal Gala' trees that had been transformed with 35S-MdMYB10 had high flesh anthocyanin concentrations but also showed considerable IFBD after cold storage. In contrast, white flesh 'Royal Gala' control fruit did not show any cortical MdMYB10 expression or IFBD symptoms and had minimal flesh anthocyanin concentrations. These results are discussed with regards to future breeding strategies that aim to optimize fruit quality in 'Type 1' red flesh breeding lines.