title: Biotechnology and apple breeding in Japan.
abstract: Apple is a fruit crop of significant economic importance, and breeders world wide continue to develop novel cultivars with improved characteristics. The lengthy juvenile period and the large field space required to grow apple populations have imposed major limitations on breeding. Various molecular biological techniques have been employed to make apple breeding easier. Transgenic technology has facilitated the development of apples with resistance to fungal or bacterial diseases, improved fruit quality, or root stocks with better rooting or dwarfing ability. DNA markers for disease resistance (scab, powdery mildew, fire-blight, Alternaria blotch) and fruit skin color have also been developed, and marker-assisted selection (MAS) has been employed in breeding programs. In the last decade, genomic sequences and chromosome maps of various cultivars have become available, allowing the development of large SNP arrays, enabling efficient QTL mapping and genomic selection (GS). In recent years, new technologies for genetic improvement, such as trans-grafting, virus vectors, and genome-editing, have emerged. Using these techniques, no foreign genes are present in the final product, and some of them show considerable promise for application to apple breeding.
authors.affiliation: Hirosaki Industrial Research Institute, Aomori Prefectural Industrial Technology Research Center , Ogimachi 1-1-8, Hirosaki, Aomori 036-8104 , Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Igarashi
authors.affiliation: Apple Research Institute, Aomori Prefectural Industrial Technology Research Center , Fukutami 24, Botandaira, Kuroishi, Aomori 036-0332 , Japan.
authors.forename: Yoshimichi
authors.initials: Y
authors.lastname: Hatsuyama
authors.affiliation: Department of Agriculture and Life Science, Hirosaki University , Bunkyouchou 3, Hirosaki, Aomori 036-8563 , Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Harada
authors.affiliation: Hirosaki Industrial Research Institute, Aomori Prefectural Industrial Technology Research Center , Ogimachi 1-1-8, Hirosaki, Aomori 036-8104 , Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Fukasawa-Akada
keywords: DNA marker; NPBTs; QTL-analysis; apple; breeding technology; trans-grafting; transgenic