Development of DNA marker for distinguishing flesh colour in sweet cherry (Prunus avium L.)

The flesh of sweet cherry (Prunus avium L.) is of two colours: red and white, and red flesh is the dominant. The Japanese prefer sweet cherries with white flesh and blush skin, these being premium fruits. Then, white-flesh cultivars are mainly cultivated in Japan. Consequently, it is important to select white-flesh individuals for breeding and the development of a DNA marker for distinguishing flesh colour is required. In a previous study, we developed a DNA marker from the PavMYB10 promoter region for discriminating flesh colour with high accuracy in the progeny line of the red-flesh cultivar ‘Benisayaka’. However, the DNA marker had low versatility in other cultivars. Therefore, we attempted to develop a DNA marker for discriminating flesh colour with high versatility. We acquired data on DNA markers located close to PavMYB10 and capable of discrimination by fragment size. Using this marker we determined the genotype for flesh colour in a segregating population resulting from ‘Nanyo’ × ‘Benisayaka’. The results revealed that the gene controlling flesh colour was located between two DNA markers in a region where there were five MYB transcription factors. Accordingly, we selected the DNA marker located close to each MYB transcription factor and determined its genotype in 88 cultivars. Consequently, it was possible to determine flesh colour using one of the three DNA markers in most cultivars. However, the result suggesting the polymorphism controlling flesh colour is still to be defined. Further identification of the polymorphisms determining flesh colour in sweet cherry is required.