Development of simple PCR-based DNA marker for the red-fleshed trait of a blood peach ‘Tenshin-suimitsuto’

Abstract

In this study, we investigated the red-fleshed trait of the peach cultivar ‘Tenshin-suimitsuto’. In addition to the anthocyanin biosynthetic gene UFGT encoding UDP-glucose:flavonoid 3-O-glucosyltransferase and the anthocyanin-regulating MYB transcription factor gene MYB10.1, we detected high expression of a NAC transcription factor gene, BLOOD (BL), in the flesh of this peach cultivar. BL is reported to induce MYB10.1 and be responsible for the red-fleshed trait of ‘Dahongpao’, suggesting that the red coloration of ‘Tenshin-suimitsuto’ is maybe controlled by BL. A transposon insertion mutation in the promoter region of BL was identified as the sole mutation co-segregating with the red-fleshed trait, indicating that anthocyanin accumulation in ‘Tenshin-suimitsuto’ is caused by this mutation and that the transposon could be a simple and accurate marker of the red coloration. F1 lines crossbred with white-fleshed cultivars bore fruits with various intensities of red coloration. We found that the intensity of flesh coloration was markedly affected by the allelic types of MYB10.1. This implies that the combination of BL and MYB10.1 markers may be relevant for the breeding of desirable red-fleshed cultivars. When grown in dark conditions, the anthocyanin content of the fruit flesh was significantly reduced but not completely eliminated. We found that the skin of ‘Tenshin-suimitsuto’ is pale red even when grown in darkness, whereas red pigmentation in white-fleshed peach skin is strictly repressed in darkness. The lower sensitivity of ‘Tenshin-suimitsuto’ to dark conditions may be caused by the high expression of BL in its skin.