Japanese citrus

The Kojiki and Nihon Shoki, compiled in the 700s, were the first books in Japan to describe citrus fruits. The Nihon Shoki states that a man named Tajimamori brought back citrus fruits from the Tokoyo no kuni (常世の国, Land of immortality) on the orders of Emperor Suinin, which is thought to refer to the tachibana orange that grows wild in Japan. The Man'yōshū, a collection of poems from the same period, contains many poems about tachibana orange, and because of its strong acidity at the time, it was dried and used for medicinal and ornamental purposes rather than for food. The Kokin Wakashū, compiled in the 900s, mentions that tachibana orange was burned and used as incense to give a nice fragrance to kimonos. In Japan, tachibana orange is a symbol of eternity and is the motif for the Order of Culture.^[1][2]

Tachibana

Iyokan

Dekopon (Hallabong, Sumo Citrus)

History

Citrus fruits are believed to have originated in Assam, India and the foothills of the Himalayas, and later spread throughout the world. Yuzu, kunembo, daidai, and kishu mikan are believed to have been introduced to Japan from China, where Kishu mikan were the mainstay until the unshu mikan became dominant.^[3] In October 2023, published genetic research proved that citrus fruits originated in Southern China, contradicting a previous study suggesting a Himalayan origin.^[4]

Japan's warm summer climate makes it particularly suitable for citrus plants; while they are grown all over the country, the largest citrus growing areas are located in the prefectures of Wakayama, Shizuoka, Tokushima, Kochi, Oita, Miyazaki and Ehime.^[5]

The most widely grown variety in Japan today is the unshu mikan (Citrus unshiu), also known as the satsuma orange. There are two theories about the origin of the unshu mikan. One is that unshu mikan originated in Japan, while the other is that it originated in China. According to the Japanese origin theory, several species that would serve as the parents of unshu mikan were introduced from China, and in the 1600s, they were crossed in Nishi-Nakajima, Higo Province (later Nagashima, Kagoshima) in Japan. The Japanese Ministry of Agriculture, Forestry and Fisheries, Ehime Prefecture and several Japanese scientists support this theory of Japanese origin.^{[6][7][8][9][10]} Genetic research has shown that the unshu mikan is a cross between the kishu and kunembo.^[11][12] During the Edo period (1603–1867), unshu mikan were not very popular due to a superstition that eating seedless unshu mikan would make one infertile. It was not until the Meiji era (1868–1912), when modernization began, that the popularity of unshu mikan increased.^[10]

From the Edo period (1603–1867) to the present, the Japanese have created numerous varieties of citrus fruits, collectively known as tyūbankan (中晩柑). It is a general term for citrus fruits shipped from January to May, after the shipping period of unshu mikan, which is from October to February.^[3][13][14] For example, natsumikan (Citrus natsudaidai) was developed around 1700,^[15] hassaku in 1860,^[16] and iyokan in 1886.^[17] Kiyomi, Setoka and Kanpei are also types of tyūbankan.^[13][14] dekopon, created in 1972, is one of the most popular varieties internationally. Dekopon was introduced to South Korea in the 1990s and became popular as Hallabong, was exported to California in 1998, and has been marketed as "Sumo Citrus" since 2011.^[18]

In Japan, various cultivars have been developed based on the unshu mikan, and three cultivars, namely miyagawa wase, okitsu wase, and aoshima unshu, account for nearly half of the production volume of unshu mikan.^[19]

Japanese taxonomy

Main article: Citrus taxonomy

Japan usually follows the botanical names of the taxonomy from Tyôzaburô Tanaka, often referred to as the "Tanaka system", giving for each cultivar a separate name no matter if it is pure or a hybrid of two or more species or varieties. While elsewhere it is more popular to classify the genus citrus into species, and further into varieties, and then into cultivars or hybrid. Such a system was created by Walter Tennyson Swingle from Florida and is called the "Swingle system".^[20] The different approaches of the two systems lead to partially-overlapping or nested 'species', for example, Citrus unshiu and Citrus tangerina (Tanaka) versus Citrus reticulata (Swingle). Likewise, common terms, like "mikan", do not always align with these taxonomic groups.

Japanese citrus (partial list)

Japanese citrus fruits include the following:

Common name(s)	Image	Taxonomic name/constituents	Notes
Amanatsu		Citrus × natsudaidai	Yellowish-orange in colour, about the size of grapefruit and oblate in shape. The fruit contains 12 segments and about 30 seeds.
Banpeiyu (pomelo cultivar)		Citrus maxima
Bushukan (Buddha's hand)		Citrus medica var. sarcodactylis
Daidai		Citrus × daidai
Dekopon		Citrus unshiu × sinensis × C. poonensis
Haruka		Citrus tamurana × natsudaidai
Hassaku		Citrus × hassaku
Hyuganatsu		Citrus tamurana
Iyokan		Citrus × iyo
Jabara		Citrus × jabara
Kabosu		Citrus sphaerocarpa
Karatachi (Japanese bitter orange)		Citrus trifoliata
Kanpei		'Dekopon' × 'nishinokaori'
Kawachi Bankan (Mishokan)		Citrus kawachiensis
Kinkan (Kumquat)		Citrus japonica
Kinkoji unshiu		Citrus obovoidea × unshiu
Kishu		Citrus kinokuni
Kiyomi		Citrus unshiu × sinensis
Kobayashi mikan		Citrus natsudaidai × unshiu
Koji orange		Citrus leiocarpa
Mikan		Citrus unshiu
Ōgonkan		Citrus flaviculpus
Ponkan (Tangerine)		Citrus poonensis
Reikou
Sakurajima komikan (mandarin orange cultivar),		Citrus × sinensis
Sanbokan		Citrus sulcata
Shonan gold		Citrus flaviculpus × Citrus unshiu
Shikuwasa (Shiikwaasaa, Shequasar, Hirami lemon)		Citrus × depressa
Sudachi		Citrus sudachi
Tachibana		Citrus tachibana or Citrus reticulata var. tachibana
Tankan		Citrus poonensis × Citrus sinensis
Tsunonozomi		'Kiyomi' × 'Encore'
Yukou		Citrus yuko
Yuzu		Citrus junos

^[21]

References

1. 日本の柑橘史 その1 (in Japanese). Japan Agricultural Cooperatives, Nishiuwa. 6 June 2019. Archived from the original on 16 October 2021. Retrieved 23 May 2023.
2. 日本の柑橘史 その2 (in Japanese). Japan Agricultural Cooperatives, Nishiuwa. 16 June 2019. Archived from the original on 16 October 2021. Retrieved 23 May 2023.
3. かんきつの歴史 (in Japanese). Shizuoka prefecture. 26 January 2023. Archived from the original on 23 May 2023. Retrieved 23 May 2023.
4. "We Finally Know Where Oranges and Lemons Come From". Scientific American. 2023-10-11. Retrieved 27 August 2024.
5. Itoh, Makiko (2014-01-14). "Juiced for a citrus winter". The Japan Times. Retrieved 2023-09-12.
6. "Hybrid Origins of Citrus Varieties Inferred from DNA Marker Analysis of Nuclear and Organelle Genomes" (PDF). Shimizu Tokurou; Kitajima Akira; Nonaka Keisuke; Yoshioka Terutaka; Ohta Satoshi; Goto Shingo; Toyoda Atsushi; Fujiyama Asao; Mochizuki Takako; Nagasaki Hideki; Kaminuma Eli; Nakamura Yasukazu. November 30, 2016. p. 50. Archived from the original (PDF) on April 26, 2019. Retrieved June 30, 2021. Therefore, it is likely that kunenbo was backcrossed to Kishu in the Kagoshima region of Japan several times and Satsuma and Yatsushiro were selected from their offspring.
7. 特集1 みかん(1) (in Japanese). The Japanese Ministry of Agriculture, Forestry and Fisheries. Archived from the original on 17 March 2023. Retrieved 23 May 2023.
8. みかんの歴史 (PDF) (in Japanese). Ehime Prefecture. p. 6. Archived from the original on 1 February 2023. Retrieved 23 May 2023.
9. Misaki, Akira (November 1999). "紀州有田みかんの起源と発達史" [The Origin and the Development-Process of "Kisyu Arida Mikan (Arida Mandarin)"]. 経済理論 [The Wakayama Economic Review] (in Japanese). 292. University of Wakayama: 97–118. Archived from the original on 2002-07-01. (After the many years of research, Dr. Tanaka has concluded the place of origin of Satsuma is Nagashima, Kagoshima. Satsuma is a chance seedling of Sōkitsu, Mankitsu, or Tendaisankitsu introduced from Huangyan Zhejiang, China. It appeared in the early Edo period. The place where Satsuma was born by mutation was Nishi-nakajima, Amakusa District, Higo Province (later Nagashima, Kagoshima), and was called Nakajima Mikan or Nagashima Mikan.)
10. "日本と世界の食事情「こたつでミカン」の光景はなぜ生まれたのか" [Food situation in Japan and the world. How did the scene of eating mikan at a kotatsu come about?]. Narumi Sato (in Japanese). Japan Business Press Co., Ltd. February 1, 2019. p. 3. Archived from the original on February 5, 2019. Retrieved June 30, 2021. During the Edo period, when Kishu mikan were being cultivated, unshu mikan were already being cultivated. However, they were not yet called unshu mikan, but Nakajima mikan. Although mandarins were a luxury, unshu mikan were not the most popular. The unshu mikan is unique in that it is ready to peel and has no seeds. The lack of seeds is good because they are easy to eat, but in the Edo period, the lack of seeds was a factor that made them unpopular. It was believed that eating seedless fruit meant that one could no longer produce offspring, thus ending one's family lineage. When the fruit was named "unshu mikan" in the late Edo period, it was finally recognized. Wenzhou is a mandarin production area in China, and the name "unshu mikan" means "a mandarin comparable to the one produced in Wenzhou". The unshu mikan is often mistaken for a mandarin imported from China, but it is a genuine Japanese mandarin. It was not until the Meiji period that the cultivation of unshu mikan became popular.
11. "Parental diagnosis of satsuma mandarin (Citrus unshiu Marc.) revealed by nuclear and cytoplasmic markers". Hiroshi Fujii, Satoshi Ohta, Keisuke Nonaka, Yuichi Katayose, Toshimi Matsumoto, etc. November 30, 2016. Archived from the original on June 30, 2021. Retrieved June 30, 2021.
12. "The genome sequence of Satsuma mandarin was unveiled". Tokurou Shimizu, Yasuhiro Tanizawa, Takako Mochizuki, Hideki Nagasaki, Terutaka Yoshioka, Atsushi Toyoda, Asao Fujiyama, Eli Kaminuma, Yasukazu Nakamura. February 20, 2018. Archived from the original on June 30, 2021. Retrieved June 30, 2021.
13. みかん？ 中晩柑？ かんきつ？ (in Japanese). Japan Agricultural Cooperatives, Nishiuwa. 6 January 2022. Archived from the original on 15 August 2022. Retrieved 23 May 2023.
14. 中晩柑とは…？ (in Japanese). 10-mikan.com. Archived from the original on 16 March 2023. Retrieved 23 May 2023.
15. ナツミカン (in Japanese). Kotobank. Archived from the original on 6 October 2022. Retrieved 23 May 2023.
16. ハッサク (in Japanese). Archived from the original on 7 October 2022. Retrieved 23 May 2023.
17. 伊予柑 (in Japanese). Kotobank. Archived from the original on 23 May 2023. Retrieved 23 May 2023.
18. 国内育成品種の海外への流出状況について (PDF) (in Japanese). The Japanese Ministry of Agriculture, Forestry and Fisheries. Archived from the original (PDF) on 30 January 2023. Retrieved 23 May 2023.
19. 温州ミカン品種別栽培面積 (in Japanese). National Agriculture and Food Research Organization. Archived from the original on 26 July 2021. Retrieved 23 May 2023.
20. Citrus Genetics... Iqrar A. Khan

    • Classifi cation of Citrus
21. Green, Aliza. (2004) Quirk Books. Field Guide to Produce: How to Identify, Select, and Prepare Virtually Every Fruit and Vegetable at the Market. Page 109. ISBN 1-931686-80-7

External links

• Japanese citrus glossary