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Triticale (× ''Triticosecale''), is a hybrid of wheat (''Triticum'') and rye (''Secale'') first bred in laboratories during the late 19th century in Scotland and Sweden. Commercially available triticale is almost always a second generation hybrid, i.e., a cross between two kinds of primary (first cross) triticales. As a rule, triticale combines the yield potential and grain quality of wheat with the disease and environmental tolerance (including soil conditions) of rye. Only recently has it been developed into a commercially viable crop. Depending on the cultivar, triticale can more or less resemble either of its parents. It is grown mostly for forage or fodder, although some triticale-based foods can be purchased at health food stores or are to be found in some breakfast cereals. When crossing wheat and rye, wheat is used as the female parent and rye as the male parent (pollen donor). The resulting hybrid is sterile, and must be treated with colchicine to induce polyploidy and thus the ability to reproduce itself. The primary producers of triticale are Poland, Germany, France, Belarus and Australia. In 2009, according to the Food and Agriculture Organization (FAO), 15.0 million tons were harvested in 29 countries across the world.〔 (【引用サイトリンク】title=Food and Agricultural commodities production )〕 The triticale hybrids are all amphidiploid, which means the plant is diploid for two genomes derived from different species. In other words, triticale is an allotetraploid. In earlier years, most work was done on octoploid triticale. Different ploidy levels have been created and evaluated over time. The tetraploids showed little promise, but hexaploid triticale was successful enough to find commercial application.〔 〕 The International Maize and Wheat Improvement Center triticale improvement program wanted to improve food production and nutrition in developing countries. Triticale has potential in the production of bread and other food products, such as cookies, pasta, pizza dough and breakfast cereals.〔 The protein content is higher than that of wheat, although the glutenin fraction is less. The grain has also been stated to have higher levels of lysine than wheat.〔 〕 Assuming increased acceptance, the milling industry will have to adapt to triticale, as the milling techniques employed for wheat are unsuited to triticale. Sell ''et al.''〔Sell, J.L.; Hodgson, G.C.; Shebeski, L.H. (1962) (''Triticale'' as a potential component of chick rations ) Canadian Journal of Animal Science, Volume 42, Number 2〕 found triticale could be used as a feed grain, and later research found its starch was particularly readily digested.〔Bird, S. H; Rowe, J. B.; Choct, M.; Stachiw, S.; Tyler, P.; Thompson, R. D. (1999) (In vitro fermentation of grain and enzymatic digestion of cereal starch ) Recent Advances in Animal Nutrition, Vol 12, pp. 53–61〕 As a feed grain, triticale is already well established and of high economic importance. It has received attention as a potential energy crop, and research is currently being conducted on the use of the crop's biomass in bioethanol production. ==Biology and genetics== Earlier work with wheat-rye crosses was difficult due to low survival of the resulting hybrid embryo and spontaneous chromosome doubling. These two factors were difficult to predict and control. To improve the viability of the embryo and thus avoid its abortion, ''in vitro'' culture techniques were developed (Laibach, 1925). Colchicine was used as a chemical agent to double the chromosomes (Blakeslee & Avery 1937). After these developments, a new era of triticale breeding was introduced. Earlier triticale hybrids had four reproductive disorders—namely, meiotic instability, high aneuploid frequency, low fertility and shriveled seed (Muntzing 1939; Krolow 1966). Cytogenetical studies were encouraged and well funded to overcome these problems. It is especially difficult to see the expression of rye genes in the background of wheat cytoplasm and the predominant wheat nuclear genome. This makes it difficult to realise the potential of rye in disease resistance and ecological adaptation. One of the ways to relieve this problem was to produce secalotricum, in which rye cytoplasm was used instead of that from wheat. Triticale is essentially a self-fertilizing, or naturally inbred, crop. This mode of reproduction results in a more homozygous genome. The crop is, however, adapted to this form of reproduction from an evolutionary point of view. Cross-fertilization is also possible, but it is not the primary form of reproduction. 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「triticale」の詳細全文を読む スポンサード リンク
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