Introduction to heirloom vegetables in Kyoto prefecture (Kyo-yasai), Japan

Abstract

The group of vegetables known collectively as Kyo-yasai is a key part of food culture in Kyoto, once Japan’s capital city for over 1000 years. A favorable climate and other cultural influences enabled Kyo-yasai culture to flourish. This study reviews the history, work to preserve, and marketing of Kyo-yasai. It also summarizes the scientific research conducted in the past few decades concerning breeding, functionality, nutrition, and taxonomy to provide an overview of Kyo-yasai today. The first record of heirloom vegetables in Japan was in the third century. After Kyoto became the capital in 794, a variety of vegetables were gradually introduced, and these have been developed and selected as Kyo-yasai for many centuries now. However, F1 vegetable cultivars became the national norm after World War II, and Kyo-yasai faced the risk of extinction. Consequently, farmers, researchers, municipalities, and other groups decided to preserve Kyo-yasai. In 1974, the Kyoto prefectural government began preserving Kyo-yasai seeds. At the time it also defined 37 heirloom vegetables as ‘traditional Kyo-yasai.’ Additionally, agricultural cooperatives, wholesale markets, restaurants, and municipalities started to promote sales of Kyo-yasai. Furthermore, a breeding program was set up by Kyoto prefectural institutes looking at ways of improving cultivation suitability. Functional and taxonomical research by Kyoto Prefectural University and other organizations has revealed not only that Kyo-yasai has higher functionality overall compared than common F1 cultivars, but also the genomic uniqueness of Kyo-yasai. These efforts collectively improved our understanding of Kyo-yasai and promoted their production. The preservation of these heirloom vegetables has a clear benefit in that it would contribute to the diversity of species and food cultures.