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Somatic fusion, also called protoplast fusion, is a type of genetic modification in plants by which two distinct species of plants are fused together to form a new hybrid plant with the characteristics of both, a somatic hybrid. Hybrids have been produced either between different varieties of the same species (e.g. between non-flowering potato plants and flowering potato plants) or between two different species (e.g. between wheat triticum and rye secale to produce Triticale). Uses of somatic fusion include making potato plants resistant to potato leaf roll disease.〔 〕 Through somatic fusion, the crop potato plant ''Solanum tuberosum'' – the yield of which is severely reduced by a viral disease transmitted on by the aphid vector – is fused with the wild, non-tuber-bearing potato ''Solanum brevidens'', which is resistant to the disease. The resulting hybrid has the chromosomes of both plants and is thus similar to polyploid plants. Somatic Hybridization was first introduced by Carlson in ''Nicotiana'' 'glauea' ==Process for plant cells== The somatic fusion process occurs in four steps:〔 .〕 # The removal of the cell wall of one cell of each type of plant using cellulase enzyme to produce a somatic cell called a protoplast # The cells are then fused using electric shock (electrofusion) or chemical treatment to join the cells and fuse together the nuclei. The resulting fused nucleus is called heterokaryon. # The somatic hybrid cell then has its cell wall induced to form using hormones # The cells are then grown into calluses which then are further grown to plantlets and finally to a full plant, known as a somatic hybrid. Different from the procedure for seed plants describe above, fusion of moss protoplasts can be initiated without electric shock but by the use of polyethylene glycol (PEG). Further, moss protoplasts do not need phytohormones for regeneration, and they do not form a callus.〔Solvey Rother, Birgit Hadeler, José M. Orsini, Wolfgang O. Abel, Ralf Reski (1994): Fate of a mutant macrochloroplast in somatic hybrids. when the potato is hybridized with tomato instead of getting any one character both character will exhibit and get a new plant called Pomato Journal of Plant Physiology 143, 72-77. ()〕 Instead, regenerating moss protoplasts behave like germinating moss spores.〔S.C. Bhatla, Justine Kiessling, Ralf Reski (2002): Observation of polarity induction by cytochemical localization of phenylalkylamine-binding receptors in regenerating protoplasts of the moss ''Physcomitrella patens''. Protoplasma 219, 99-105. ()〕 Of further note sodium nitrate and calcium ion at high pH can be used, although results are variable depending on the organism.〔Mahesh. Plant Molecular biotechnology. 2009. Book.〕 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「Somatic fusion」の詳細全文を読む スポンサード リンク
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