Citrus unshiu

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Citrus unshiu
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Sapindales
Family: Rutaceae
Genus: Citrus
C. unshiu
Binomial name
Citrus unshiu
(Yu.Tanaka ex Swingle) Marcow.

Citrus unshiu is a semi-seedless and easy-peeling citrus species, also known as the satsuma mandarin or Japanese mandarin.[1] During the Edo period of Japan, kishu mikans were more popular because there was a popular superstition that eating Citrus unshiu without seeds made people prone to infertility. Citrus unshiu became popular in Japan after modernization started in the Meiji period.[2] It was introduced to the West from the Satsuma region of Japan in 1878.[3]

Citrus unshiu was named after Unshu (Wenzhou), a famous production area of mandarin oranges in China, in the late Edo period of Japan. Before the name unshu mikan was established in Japan, it was called nakajima mikain or nagashima mikan after the place name of Nishi-Nakajima in Amakusa District of the Higo Province (later Nagashima, Kagoshima), where the species was thought to have developed by mutation.[4][2] It is said to have originated in either Japan[5][4][2] or China, and because of its name, it is often described as originating in China.[3][6][7] Genetic studies conducted in the 2010s suggest that the maternal species of Citrus unshiu is kishu (Citrus kinokuni) and the paternal species is kunenbo (Citrus nobilis Lour. var. kunip).[8][9]

Various cultivars have been developed based on the Citrus unshiu, and in Japan, three cultivars, namely miyagawa wase, okitsu wase, and aoshima unshu, account for nearly half of the production volume of Citrus unshiu.[10]


The unshiu is known as wēnzhōu mìgān (simplified Chinese: 温州蜜柑; traditional Chinese: 溫州蜜柑) in China, and mikan in Japan (or formally unshū mikan (温州蜜柑), the Japanese reading of the characters used in Chinese). In both languages, the name means "honey citrus of Wenzhou" (a city in Zhejiang province, China). An alternative Chinese name, wúhé jú (simplified Chinese: 无核橘; traditional Chinese: 無核橘), means "seedless mandarin".

One of the English names for the fruit, satsuma, is derived from the former Satsuma Province in Japan, from which these fruits were first exported to the West.[3]

The Afrikaans name naartjie is also used in South African English. It came originally from the Tamil word nartei, meaning citrus.[11]


Under the Tanaka classification system, Citrus unshiu is considered a separate species from the mandarin. Under the Swingle system, unshius are considered to be a group of mandarin varieties.[12] Genetic analysis has shown the Satsuma to be a highly inbred mandarin-pomelo hybrid, with 22% of its genome, a larger proportion than seen in most mandarins, coming from pomelo. It arose when a mandarin of the low-pomelo Huanglingmiao or kishumikan variety (placed in C. reticulata by Tanaka) was crossed with a pomelo or pomelo hybrid, then the resulting cultivar was backcrossed with another Huanglingmiao or kishumikan mandarin.[9][13][14]


The dried peel is used in Chinese cuisine
Satsuma orange trees in Izunokuni, Shizuoka Prefecture, Japan
Satsuma orange fruits

Citrus unshiu is one of the sweetest citrus varieties.[15] It is usually seedless, and is about the size of other mandarin oranges (Citrus reticulata). Satsumas are known for their loose, leathery skin; the fruit is very easily peeled in comparison to other citrus fruits.[16] The rind is often smooth to slightly rough with the shape of a medium to small flattened sphere.[17][18] Satsumas usually have 10 to 12 easily separable segments with tough membranes.[18] The flesh is particularly delicate, and cannot withstand the effects of careless handling.[16] Coloring of the fruit is often dependent on climate; satsumas grown in humid areas may be ripe while the skin is still green while those grown in areas with cool night temperatures may see a brilliant reddish orange skin at peak.[18]

Satsumas are cold-hardy, and when planted in colder locations, the fruit becomes sweeter from the colder temperatures. A mature satsuma tree can survive down to −9 °C (15 °F) or even −11 °C (12 °F) for a few hours.[19] Of the edible citrus varieties, only the kumquat is more cold-hardy. Satsumas rarely have any thorns, an attribute that also makes them popular.[18] They can be grown from seed, which takes about eight years until the first fruits are produced, or grafted onto other citrus rootstocks, such as trifoliate orange.[18]


United States of America[edit]

Jesuits brought the fruit from Asia to North America in the 18th century, starting groves in the Jesuit Plantation upriver from New Orleans, Louisiana (then a part of New Spain). The municipal street "Orange" in New Orleans, was originally named "Rue Des Orangers" and the site of the Jesuit grove. The groves were later re-cultivated farther south in Plaquemines Parish to provide greater protection from harmful frosts, and have continued to the present day. The Becnel family are the largest growers of Louisiana citrus.[20]

The fruit became much more common in the United States starting in the late 19th century. In 1878 during the Meiji period, Owari mikans were brought to the United States from the Satsuma Province in Kyūshū, Japan, by Anna Van Valkenburgh,[21] the spouse of the US Minister to Japan, General Van Valkenburgh, who renamed them satsumas.[3][22] Between 1908 and 1911 about a million Owari mikan trees were imported throughout the lower Gulf Coast states.[19] Owari is still commonly grown in Florida.[18] The towns of Satsuma, Alabama, Satsuma, Florida, Satsuma, Texas, and Satsuma, Louisiana were named after this fruit. By 1920 Jackson County in the Florida Panhandle had billed itself as the "Satsuma Capital of the World." However, the commercial industry was damaged by a −13.3 °C (8.1 °F) cold snap in 1911, a hurricane in 1915,[19] and a very cold period in the late 1930s.


Citrus unshiu is amongst others grown in Japan, Spain, central China, Korea, the US, South Africa, South America, New Zealand, and around the Black Sea.[18][22]


Unshiu varieties cluster among the mandarin family.[23] There are, however, some hybrids.

Possible non-hybrids[edit]



  1. ^ Michel H. Porcher (ed.). "Sorting Citrus names". Multilingual Multiscript Plant Name Database. The University of Melbourne.
  2. ^ a b c "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.
  3. ^ a b c d The Satsuma Mandarin University of Florida
  4. ^ a b 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). University of Wakayama. 292: 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.)
  5. ^ "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.
  6. ^ Schlegel, Rolf (2009). Dictionary of Plant Breeding (2nd ed.). CRC Press. p. 437. ISBN 9781439802434.
  7. ^ "Japanese Mikan and Satsuma Oranges". Mikan is a tangerine-like citrus fruit that is grown in warmer regions of Japan in large quantities. Many different varieties have been introduced to Japan from China since the eighth century, but since the late 19th century the most important variety has been the unshu.
  8. ^ "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.
  9. ^ a b "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.
  10. ^ 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.
  11. ^ Branford, Jean (1978). A dictionary of South African English. Oxford University Press.
  12. ^ Froelicher, Yann; Mouhaya, Wafa; Bassene, Jean-Baptiste; Costantino, Gilles; Kamiri, Mourad; Luro, Francois; Morillon, Raphael; Ollitrault, Patrick (2011). "New universal mitochondrial PCR markers reveal new information on maternal citrus phylogeny". Tree Genetics & Genomes. 7: 49–61. doi:10.1007/s11295-010-0314-x. S2CID 32371305.
  13. ^ Wu, Guohong Albert; Terol, Javier; Ibanez, Victoria; López-García, Antonio; Pérez-Román, Estela; Borredá, Carles; Domingo, Concha; Tadeo, Francisco R; Carbonell-Caballero, Jose; Alonso, Roberto; Curk, Franck; Du, Dongliang; Ollitrault, Patrick; Roose, Mikeal L. Roose; Dopazo, Joaquin; Gmitter Jr, Frederick G.; Rokhsar, Daniel; Talon, Manuel (2018). "Genomics of the origin and evolution of Citrus" (PDF). Nature. 554 (7692): 311–316. Bibcode:2018Natur.554..311W. doi:10.1038/nature25447. PMID 29414943. S2CID 205263645. and Supplement
  14. ^ Shimizu, Tokurou; Kitajima, Akira; Nonaka, Keisuke; Yoshioka, Terutaka; Ohta, Satoshi; Goto, Shingo; Toyoda, Atsushi; Fujiyama, Asao; Mochizuki, Takako; Nagasaki, Hideki; Kaminuma, Eli; Nakamura, Yasukazu (30 November 2016). "Hybrid Origins of Citrus Varieties Inferred from DNA Marker Analysis of Nuclear and Organelle Genomes". PLOS ONE. 11 (11): e0166969. Bibcode:2016PLoSO..1166969S. doi:10.1371/journal.pone.0166969. PMC 5130255. PMID 27902727. e0166969.
  15. ^ Elisa Bosley. "In Season: Satsuma Oranges". CookingLight. Retrieved 2015-02-25.
  16. ^ a b Silvia Bautista-Baños; Gianfranco Romanazzi; Antonio Jiménez-Aparicio (2016). Chitosan in the Preservation of Agricultural Commodities. Elsevier Science. p. 76. ISBN 978-0-12-802757-8.
  17. ^ "frostowari". Retrieved 2020-04-23.
  18. ^ a b c d e f g Andersen, Peter C.; Ferguson, James J (2019). "HS195/CH116: The Satsuma Mandarin". University of Florida Institute of Food and Agricultural Sciences. Retrieved 29 December 2020.
  19. ^ a b c ""Orange Frost", a new cold hardy citrus". PLANTanswers.
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  21. ^ "Anna Van Valkenburgh". geni_family_tree. 1827. Retrieved 2023-12-14.
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  24. ^ "Kinkoji unshiu mandarin (graft) hybrid Citrus neo-aurantium". Citrus Variety Collection. University of California Riverside.
  25. ^ Kuniaki Sugawara; Atsushi Oowada; Takaya Moriguchi1; Mitsuo Omura (1995). "Identification of Citrus Chimeras by RAPD Markers" (PDF). HortScience. 30 (6): 1276–1278. doi:10.21273/HORTSCI.30.6.1276.{{cite journal}}: CS1 maint: numeric names: authors list (link)

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