Study On The Technique System Of Tissue Culture Of Rieger Begonia

Through direct induction of adventitious buds, stems, leaves and leafstalks were used as explants to establish a rapid and effective technique system of tissue culture of Rieger Begonia. Suitable culture factors were selected by single factor design and optimum technical parameter association was found by orthogonal designed experiment. With MS as minimal medium, this experiment studied effect of the type of explants and their pretreatments, as well as the type of auxins and cytokines and their ratios on the bud differentiation. We tested different hormones to decide the suitable auxins and cytokines and their ratio for multiplication culture, based on which we studied effect of the forms of nitrogen and their ratio, and the concentrations of KH₂PO₄ and cane sugar on multiplication. Above all a comparative test was carried out about the multiplication efficiencies of cane sugar and sand sugar. In the end, with a L₉ (3⁴) Orthogonal Designed Experiment we established the optimum association of IBA, KT and multiplication cycle. Based optimum technical parameter association on analysis of range, variance further and multiple compare to the result of the test, the efficiency in vitro culture of Rieger Begonia was improved greatly. The results were as follows:(1)Medium-matured stems (lead buds) of Rieger Begonia showed lower death rate, quicker differentiation speed and higher differentiation rate than leaves and leafstalks. (2)After preserved at 4℃ for 20 hours before sterilization seepage discharge of secretion form the stems and leafstalks of Rieger Begonia descended significantly. (3)NAA and 6-BA could promote greatly differentiation of adventitious buds of Rieger Begonia and the highest differentiation rate showed in the treatment of 0.75mg·L^-16-BA+0.1mg·L^-1NAA. (4)NAA and KT are the suitable auxins and cytokines respectively in vitro culture of Rieger Begonia and the best multiplication efficiency was obtained in the treatment of 0.5mg·L^-1KT + 0.08mg·L^-1NAA. In addition, bunch buds of Rieger Begonia grew slowly, so the multiplication cycle should be prolonged to 40d. (5)Single form of nitrogen could not satisfied the multiplication of Rieger Begonia. On the basis of MS amount, high-concentration NH₄⁺ had function of poisoning bunch buds; comparatively speaking, high-concentration NO₃^- could promote multiplication of Rieger Begonia. Different ratios of NH₄⁺ and NO₃^- in the medium had different results, 1/2 was the best. (6) Adventitious buds of Rieger Begonia could multiplicand normally in the...