Allelic composition of MdMYB1 drives red skin color intensity in apple (Malus × domestica Borkh.) and its application to breeding

• Published in: Euphytica Vol. 213; no. 4; pp. 1 - 13
• Main Authors: Moriya, Shigeki, Kunihisa, Miyuki, Okada, Kazuma, Shimizu, Taku, Honda, Chikako, Yamamoto, Toshiya, Muranty, Hélène, Denancé, Caroline, Katayose, Yuichi, Iwata, Hiroyoshi, Abe, Kazuyuki
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.04.2017; Springer; Springer Nature B.V
• Subjects: Apple; Apples; Biomedical and Life Sciences; Biotechnology; Climate change; Color; Cultivars; Fruits; Genomics; Global climate; Global warming; Life Sciences; Malus domestica; Phenotypic variations; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Skin; Anthocyanin; Quantitative trait; Fruit color; Marker-assisted selection; Genome-wide association study
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-017-1864-x

Since apple fruit skin reddens poorly under warmer climates, new apple cultivars are desired that are adapted to global warming in terms of bearing well-reddened fruit. We developed a simple sequence repeat marker, Mdo.chr9.4, which is suitable for red skin color selection. It amplified four alleles (Mdo.chr9.4-R 0 , Mdo.chr9.4-Y −3 , Mdo.chr9.4-Y −9 , and Mdo.chr9.4-Y −15 ) distinguished by length. Mdo.chr9.4-R 0 associated with MdMYB1 - 1 which confers red fruit skin. The presence of Mdo.chr9.4-R 0 was consistent with empirical skin color in all 160 tested accessions. Mdo.chr9.4 was identified as the only significant marker that contributed to red skin color intensity by a genome wide association study (GWAS), and it accounted for 52.0% of phenotypic variation, confirming that MdMYB1 was the major and principal determinant of fruit skin color in apples. Individuals with a homozygous state of Mdo.chr9.4-R 0 (dose 2) were significantly redder than those showing a heterozygote state (dose 1) in both the accession set and full-sib families, indicating a partially dominant effect of MdMYB1 - 1 . Therefore, the selection of dose 2 individuals would target individuals with intensive red skin. We applied Mdo.chr9.4 to several application populations using a time and cost-efficient genotyping system developed in the present study. This system, along with Mdo.chr9.4, provide advanced marker-assisted breeding for intensive red skin color apples adapted to a global warming climate.