The species has an erect stalk stem that grows 80–120 cm (30–45 in) tall, with a smooth surface. The leaf is lanceolate, 15–30 cm (5+7⁄8–11+3⁄4 in) long, and grows from a ligule 10–20 mm (3⁄8–3⁄4 in) long.[7]
Classificationedit
Oryza sativa contains two major subspecies: the sticky, short-grained japonica or sinica variety, and the nonsticky, long-grained indica[zh] [ja] rice variety. Japonica was domesticated in the Yangtze Valley 9–6,000 years ago,[8] and its varieties can be cultivated in dry fields (it is cultivated mainly submerged in Japan), in temperate East Asia, upland areas of Southeast Asia, and high elevations in South Asia, while indica was domesticated around the Ganges 8,500-4,500 years ago,[8] and its varieties are mainly lowland rices, grown mostly submerged, throughout tropical Asia. Rice grain occurs in a variety of colors, including white, brown, black, purple, and red rices.[9][10]
A third subspecies, which is broad-grained and thrives under tropical conditions, was identified based on morphology and initially called javanica, but is now known as tropical japonica. Examples of this variety include the medium-grain 'Tinawon' and 'Unoy' cultivars, which are grown in the high-elevation rice terraces of the Cordillera Mountains of northern Luzon, Philippines.[11]
Glaszmann (1987) used isozymes to sort O. sativa into six groups: japonica, aromatic, indica, aus, rayada, and ashina.[12]
Garris et al. (2004) used simple sequence repeats to sort O. sativa into five groups: temperate japonica, tropical japonica and aromatic comprise the japonica varieties, while indica and aus comprise the indica varieties.[13]
Nomenclature and taxonomyedit
Rice has been cultivated since ancient times and oryza[14] is a classical Latin word for rice while sativa[15] means "cultivated".
O. sativa uses the plant hormones abscisic acid and salicylic acid to regulate immune responses.[22] Salicylic acid broadly stimulates, and abscisic acid suppresses, immunity to the rice blast fungus M. grisea; success depends on the balance between their levels.[22]
^"Oryza sativa L." Plants of the World Online. Board of Trustees of the Royal Botanic Gardens, Kew. 2017. Retrieved December 21, 2020.
^Normile, Dennis (1997). "Yangtze seen as earliest rice site". Science. 275 (5298): 309–310. doi:10.1126/science.275.5298.309. S2CID 140691699.
^Vaughan, D.A.; Lu, B.; Tomooka, N. (2008). "The evolving story of rice evolution". Plant Science. 174 (4): 394–408. doi:10.1016/j.plantsci.2008.01.016.
^Harris, David R. (1996). The Origins and Spread of Agriculture and Pastoralism in Eurasia. Psychology Press. p. 565. ISBN 978-1-85728-538-3.
^Zhang, Jianping; Lu, Houyuan; Gu, Wanfa; Wu, Naiqin; Zhou, Kunshu; Hu, Yayi; Xin, Yingjun; Wang, Can; Kashkush, Khalil (December 17, 2012). "Early Mixed Farming of Millet and Rice 7800 Years Ago in the Middle Yellow River Region, China". PLOS ONE. 7 (12): e52146. Bibcode:2012PLoSO...752146Z. doi:10.1371/journal.pone.0052146. PMC3524165. PMID 23284907.
^Haberer, Georg; Mayer, Klaus F.X.; Spannagl, Manuel (April 1, 2016). "The big five of the monocot genomes". Current Opinion in Plant Biology. SI: 30: Genome studies and molecular genetics. 30: 33–40. doi:10.1016/j.pbi.2016.01.004. ISSN 1369-5266.
^Catindig, J.L.A.; Lubigan, R.T.; Johnson, D. (n.d.). "Oryza sativa". Rice Knowledge Bank. International Rice Research Institute. Retrieved June 29, 2023.
^ abPurugganan, Michael D.; Fuller, Dorian Q. (2009). "The nature of selection during plant domestication". Nature. 457 (7231). Nature Research: 843–848. Bibcode:2009Natur.457..843P. doi:10.1038/nature07895. ISSN 0028-0836. PMID 19212403. S2CID 205216444.
^Mohammadi Shad, Z.; Atungulu, G. (March 2019). "Post-harvest kernel discoloration and fungi activity in long-grain hybrid, pureline and medium-grain rice cultivars as influenced by storage environment and antifungal treatment". Journal of Stored Products Research. 81: 91–99. doi:10.1016/j.jspr.2019.02.002. S2CID 92050510.
^CECAP, PhilRice and IIRR. 2000. "Highland Rice Production in the Philippine Cordillera."
^Glaszmann, J. C. (May 1987). "Isozymes and classification of Asian rice varieties". Theoretical and Applied Genetics. 74 (1): 21–30. doi:10.1007/BF00290078. PMID 24241451. S2CID 22829122.
^Garris, Amanda J.; Tai, T. H.; Coburn, J.; Kresovich, S.; McCouch, S. (2004). "Genetic structure and diversity in Oryza sativa L." Genetics. 169 (3): 1631–1638. doi:10.1534/genetics.104.035642. PMC1449546. PMID 15654106.
Pieterse, Corné M.J.; Van der Does, Dieuwertje; Zamioudis, Christos; Leon-Reyes, Antonio; Van Wees, Saskia C.M. (November 10, 2012). "Hormonal Modulation of Plant Immunity". Annual Review of Cell and Developmental Biology. 28 (1). Annual Reviews: 489–521. doi:10.1146/annurev-cellbio-092910-154055. hdl:1874/274421. ISSN 1081-0706. PMID 22559264. S2CID 18180536.
Atkinson, Nicky J.; Urwin, Peter E. (March 30, 2012). "The interaction of plant biotic and abiotic stresses: from genes to the field". Journal of Experimental Botany. 63 (10). Oxford University Press: 3523–3543. doi:10.1093/jxb/ers100. ISSN 0022-0957. PMID 22467407. S2CID 205195661.
Liu, Wende; Liu, Jinling; Triplett, Lindsay; Leach, Jan E.; Wang, Guo-Liang (August 4, 2014). "Novel Insights into Rice Innate Immunity Against Bacterial and Fungal Pathogens". Annual Review of Phytopathology. 52 (1). Annual Reviews: 213–241. doi:10.1146/annurev-phyto-102313-045926. ISSN 0066-4286. PMID 21380629. S2CID 9244874.
External linksedit
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