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A cultigen (from the Latin ''cultus'' - cultivated, and ''gens'' - kind) is a plant that has been deliberately altered or selected by humans; it is the result of artificial selection. These "man-made" or anthropogenic plants are, for the most part, plants of commerce that are used in horticulture, agriculture and forestry. Because cultigens are defined by their mode of origin and not by where they are growing, plants meeting this definition remain cultigens whether they are naturalised in the wild, deliberately planted in the wild, or growing in cultivation. Cultigens arise in the following ways: selections of variants from the wild or cultivation including vegetative sports (aberrant growth that can be reproduced reliably in cultivation); plants that are the result of plant breeding and selection programs; genetically modified plants (plants modified by the deliberate implantation of genetic material); and graft-chimaeras (plants grafted to produce mixed tissue, the graft material possibly from wild plants, special selections, or hybrids). Cultigens may be named in any of a number of ways. The traditional method of scientific naming is under the ''International Code of Nomenclature for algae, fungi, and plants'', and many of the most important cultigens, like maize (''Zea mays'') and banana (''Musa acuminata''), are so named. Although it is perfectly in order to give a cultigen a botanical name, in any rank desired, now or at any other time,〔 Art. 28 "Note 3. Nothing precludes the use, for cultivated plants, of names published in accordance with the requirements of this Code."〕 these days it is more common for cultigens to be given names in accordance with the principles, rules and recommendations laid down in the International Code of Nomenclature for Cultivated Plants (ICNCP) which provides for the names of cultigens in three classification categories, the cultivar, the Group (formerly cultivar-group), and the grex.〔The category grex was added in the 2009 ''Cultivated Plant Code'' and applies only to orchids (Article 4).〕 From that viewpoint it may be said that there is a separate discipline of cultivated plant taxonomy, which forms one of the ways to look at cultigens. The ICNCP does not recognize the use of trade designations and other marketing devices as scientifically acceptable names, but does provide advice on how they should be presented.〔 Article 10 and Appendix 10.〕 Not all cultigens have been given names according to the ''Cultivated Plant Code''. Apart from ancient cultigens like those mentioned above there may be occasional anthropogenic plants such as those that are the result of breeding, selection, and tissue grafting that are of no commercial value and have therefore not been given names according to the ICNCP. == Formal definition == A cultigen is a plant whose origin or selection is primarily due to intentional human activity.〔Spencer, R.D. and Cross, R.G. 2007. The cultigen. ''Taxon'' 56(3):938-940〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「cultigen」の詳細全文を読む スポンサード リンク
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