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Improvement of Plant Genetic Variability through Soma- clonal Variations. Sri Hutami, Ika Mariska, and Yati Supriati. High genetic variability’s are important factors in the development of new crop varieties. In vitro techniques are applicable for development of crop variability that is not found in the gene pool. One of the in vitro techniques that can be used for this purpose is the somaclonal variation technique. Somaclonal variation may be derived from gen- etic variations in explants and genetic variations in tissue cultures. Variations in the explant may be obtained from cell mutations or polysomic mutations of a certain tissue. Gen- etic variations in tissue culture may be caused by ploidy of chromosomes (endomitosis fusion), changes of chromosom structures (crossings), as well as changes of genes and cyto- plasms. Changes of genetic characters may be improved if anorganic compound was added into the medium. To im- prove the plant tolerances to biotic or abiotic factors, selec- tion components may also be added to the medium. Re- search results showed that somaclonal variation in tissue culture can improve genetic variations in plants. The vari- ation produced in tissue culture provide chances to develop new plant genotipes. Many selection components, such as Gamma-ray irradiation, Al contents and low pH, pure toxin or filtrate, polyethylene glycol (PEG), and plant growth regula- tors can be used to improve somaclonal variations in many plants to produce new genotipes. |
