Advances in table grape breeding in Japan.

Area of Science:

• Horticulture and Plant Breeding
• Viticulture
• Genetics

Background:

• Limited native Vitis vinifera cultivars in Japan due to high rainfall and disease susceptibility.
• Introduction of Vitis labruscana and V. vinifera in the 19th century, with V. labruscana favored for disease resistance.
• Challenges of berry cracking and disease in V. vinifera hindered its cultivation in Japan.

Purpose of the Study:

• To trace the history and strategies of Japanese grape breeding for table use.
• To understand the development of cultivars combining desirable traits from V. vinifera and V. labruscana.
• To highlight key cultivars resulting from different breeding approaches.

Main Methods:

• Historical review of grape introduction and breeding in Japan.
• Analysis of breeding strategies including intraspecific and interspecific crossings.
• Examination of cultivar development from diploid and tetraploid crosses.

Main Results:

• Early 20th-century breeding focused on combining V. vinifera quality with V. labruscana cultivation.
• Development of 'Neo Muscat', 'Kyoho', and 'Muscat Bailey A' through various crossing strategies by 1945.
• Subsequent tetraploid interspecific crossing led to 'Kyoho'-related cultivars ('Pione') with large berries and moderate disease resistance.
• Diploid interspecific crossing resulted in 'Shine Muscat' (2006) with seedless, crack-resistant fruit and desirable flavor.

Conclusions:

• Japanese grape breeding successfully integrated traits from different Vitis species.
• Interspecific hybridization has been crucial for developing cultivars adapted to local conditions.
• 'Shine Muscat' exemplifies modern advancements in seedless grape development with enhanced traits.