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A cultivar〔Cultivar has two meanings as explained under ''Formal definition.'' When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar.〕 is a plant or grouping of plants selected for desirable characteristics that can be maintained by propagation. Most cultivars have arisen in cultivation but a few are special selections from the wild. Popular ornamental garden plants like roses, camellias, daffodils, rhododendrons, and azaleas are cultivars produced by careful breeding and selection for flower colour and form. Similarly, the world's agricultural food crops are almost exclusively cultivars that have been selected for characteristics such as improved yield, flavour, and resistance to disease: very few wild plants are now used as food sources. Trees used in forestry are also special selections grown for their enhanced quality and yield of timber. Cultivars form a major part of Liberty Hyde Bailey's broader grouping, the cultigen, defined as a plant whose origin or selection is primarily due to intentional human activity. ''Cultivar'' was coined by Bailey and it is generally regarded as a portmanteau of "cultivated" and "variety", but could also be derived from "cultigen" and "variety". A cultivar is not the same as a botanical variety, and there are differences in the rules for the formation and use of the names of botanical varieties and cultivars. In recent times the naming of cultivars has been complicated by the use of statutory plant patents and plant breeders' rights names.〔(See )〕 The International Union for the Protection of New Varieties of Plants (UPOV – French: ''Union internationale pour la protection des obtentions végétales'') offers legal protection of plant cultivars to people or organisations who introduce new cultivars to commerce. UPOV requires that a cultivar be distinct, uniform and stable. To be distinct, it must have characteristics that easily distinguish it from any other known cultivar. To be uniform and stable, the cultivar must retain these characteristics under repeated propagation. The naming of cultivars is an important aspect of cultivated plant taxonomy, and the correct naming of a cultivar is prescribed by the Rules and Recommendations of the ''International Code of Nomenclature for Cultivated Plants'' (the ''ICNCP'', commonly known as the ''Cultivated Plant Code''). A cultivar is given a cultivar name, which consists of the scientific Latin botanical name followed by a cultivar epithet. The cultivar epithet is usually in a vernacular language. For example, the full cultivar name of the King Edward potato is ''Solanum tuberosum'' 'King Edward'. The 'King Edward' part of the name is the cultivar epithet which, according to the Rules of the ''Cultivated Plant Code'', is bounded by single quotation marks.〔Cultivated Plant Code Article 14.1 〕 == Origin of term == (詳細はTheophrastus (370–285 BCE), the "Father of Botany", who was keenly aware of this difference. Botanical historian Alan Morton notes that Theophrastus in his ''Enquiry into Plants'' "''had an inkling of the limits of culturally induced (phenotypic) changes and of the importance of genetic constitution''" (''Historia Plantarum'' III, 2,2 and ''Causa Plantarum'' I, 9,3). The International Code of Nomenclature for algae, fungi, and plants uses as its starting point for modern botanical nomenclature those Latin names that appeared in Linnaeus' publications ''Species Plantarum'' (10th ed.) and ''Genera Plantarum'' (5th ed.). In ''Species Plantarum'', Linnaeus (1707–1778) listed all the plants known to him, either directly or from his extensive reading. He recognised the rank of varietas (in English this is the botanical "variety", a rank below that of species and subspecies) and he indicated these varieties by using letters of the Greek alphabet such as α, β, λ in front of the variety name, rather than using the abbreviation var., which is the current convention. Most of the varieties listed by Linnaeus were of "garden" origin rather than being wild plants. Over time there was an increasing need to distinguish between plants growing in the wild, and those with variations that had been produced in cultivation. In the nineteenth century many "garden-derived" plants were given horticultural names, sometimes in Latin and sometimes in a local language. From about the 1900s, plants produced in cultivation in Europe were recognised in the Scandinavian, Germanic, and Slavic literature through the words ''stamm'' or ''sorte'' but these words could not be used internationally since, by international agreement, any new terms had to be based in Latin. In the twentieth century an improved international terminology was proposed for the classification and nomenclature of cultivated plants. The word ''cultivar'' was coined in 1923 by Liberty Hyde Bailey of Cornell University, New York State, when he wrote: ''The cultigen is a species, or its equivalent, that has appeared under domestication – the plant is cultigenous. I now propose another name, cultivar, for a botanical variety, or for a race subordinate to species, that has originated under cultivation; it is not necessarily, however, referable to a recognized botanical species. It is essentially the equivalent of the botanical variety except in respect to its origin.'' In this paper Bailey used only the rank of species for the cultigen but it was clear to him that many domesticated plants were more like botanical varieties than species, and that appears to have motivated the suggestion of the new classification category ''cultivar'', which is generally assumed to be a contraction of the words ''cultivated'' and ''variety''. However, Bailey was never explicit about the etymology of the word, and it has been suggested that it is a contraction of the words ''cultigen'' and ''variety'', which seems more appropriate. The new word ''cultivar'' was promoted as "euphonious" and that "it is free from ambiguity". It serves a purpose.〔〔This ignored its prior existence as a transitive verb in Spanish, meaning "to farm, to cultivate, to grow, or to practice". (Online Spanish dictionary ), and in Portuguese meaning ''to cultivate, to husband, to farm, to plant, to polish, to reclaim, to improve''. (Ectaco online Portuguese dictionary )〕 Its use was subsequently recommended by the first ''Cultivated Plant Code'', which was published in 1953, and by 1960 it had achieved wide international acceptance. 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「cultivar」の詳細全文を読む スポンサード リンク
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