著者
Kyoko Yamane Yasuaki Sugiyama Yuan-Xue Lu Na Lű Kenichi Tanno Eri Kimura Hirofumi Yamaguchi
出版者
The Japanese Society for Horticultural Science
雑誌
The Horticulture Journal (ISSN:21890102)
巻号頁・発行日
pp.MI-065, (Released:2015-07-30)
被引用文献数
4 8

This paper reports the level of genetic differentiation between two Japanese and one Chinese species of Eutrema: E. japonicum, “wasabi”; its wild relative in Japan, E. tenue; and their wild relative in China, E. yunnanense. Phylogenetic analyses were based on the DNA sequence of the chloroplast trnK/matK region of 16 Brassicaceae and an outgroup species. Neighbor joining (NJ) and maximum parsimony (MP) trees were constructed, revealing that the three Eutrema species form a single clade clearly separated from other Brassicaceae species. The two Japanese Eutrema species are highly differentiated from Chinese E. yunnanense, and it is estimated that they diverged from E. yunnanense approximately 5 million years ago. An ethnobotanical survey was conducted among ethnic Chinese in Yunnan Province, and the results indicate that E. yunnanense is not perceived as “hot” in taste, while a pungent flavor is associated with wasabi; in addition, no evidence was found for the domestication of E. yunnanense. On the basis of the present molecular phylogenetic study and the ethnobotanical survey, we conclude that wasabi acquired its specific pungent flavor during its long botanical history in Japan, and that its subsequent domestication in Japan was because of this acquired pungent flavor. The culinary habit of using wasabi with raw fish has since become an important feature of Japanese cuisine and culture.
著者
Kyoko Yamane Tomoe Yamada-Kato Natsuko Haga Kaori Ishida Seiji Murayama Keiko Kobayashi Isao Okunishi
出版者
Japanese Society of Breeding
雑誌
Breeding Science (ISSN:13447610)
巻号頁・発行日
vol.73, no.3, pp.237-245, 2023 (Released:2023-07-27)
参考文献数
46

Wasabi (Japanese horseradish, Eutrema japonicum) is the only cultivated species in the genus Eutrema with functional components that provide a strong pungent flavor. To evaluate genetic resources for wasabi breeding, we surveyed variations in the two most abundant isothiocyanate (ITC) components in wasabi, allyl isothiocyanate (AITC) and 6-methylsulfinyl (hexyl) isothiocyanate (6-MSITC, hexaraphane). We also examined the phylogenetic relationships among 36 accessions of wild and cultivated wasabi in Japan using chloroplast DNA analysis. Our results showed that (i) the 6-MSITC content in currently cultivated wasabi accessions was significantly higher than in escaped cultivars, whereas the AITC content was not significantly different. (ii) Additionally, the 6-MSITC content in cultivated wasabi was significantly lower in the spring than during other seasons. This result suggested that the 6-MSITC content responds to environmental conditions. (iii) The phylogenetic position and the 6-MSITC content of accessions from Rebun, Hokkaido Prefecture had different profiles compared with those from southern Honshu, Japan, indicating heterogeneity of the Rebun populations from other Japanese wasabi accessions. (iv) The total content of AITC and 6-MSITC in cultivated wasabi was significantly higher than that of wild wasabi. In conclusion, old cultivars or landraces of wasabi, “zairai”, are the most suitable candidates for immediate use as genetic resources.