影响小麦成熟胚培养因素的研究

Studies on the Factors Affecting Mature Embryo Culture of Wheat

利用110多个小麦品种的种子为材料,研究了影响成熟胚培养效果的几个因素.实验结果表明,基因型是重要的影响因子,引起愈伤组织的生长速度和一次成苗率等性状的明显差异.培养基的成份也起着重要作用,2,4-D是必需的生长素,使用浓度的范围较大,但浓度太高会降低愈伤组织的生长速度,并明显抑制器官分化;0.5～1毫克/升的NAA和GA_3与0.5～1毫克/升2,4-D配合作用对培养有益,一次成苗率较高,同样浓度的ABA仅对根分化有促进作用;培养基中蔗糖浓度在3～7%有助于愈伤组织生长.另一个影响因子是愈伤组织的继代时间长度,短时间继代培养(不超过一年)能改善愈伤组织的质量并加快其增殖,超过一年的长时间继代培养虽不影响愈伤组织的增长速率,但使绿苗分化率剧烈下降,白苗分化率上升.通过筛选适宜的基因型和调节培养基中的激素,亦获得了较高的绿苗分化频率.

The seeds from 110 cultivars of wheat were used to examine the factors affecting the efficiency of mature emoryo culture. The experimental results demonstrated:( 1 ) Genotype was a critical factor, which could cause remarkable differences in callus growth rate and frequency of one-step regeneration from the cultured embryos.( 2 ) Composition of the culture medium also played an important role in the culture. 2,4-D was an essential hormone and had a wide range of usable concentrations. But at excessive levels, it could slow down the growth of callus and seriously inhibit differentiation of organs. 0.5-1 mg/1 NAA or GA in cooperation with 0.5-1 mg/1 2,4-D was proven beneficial to the culture and resulted in a considerable higher frequency of one-step regeneration. ABA at the same levels promoted only root differentiation. Concentration of sucrose of 3-7% in the medium was found to be helpful to callus growth.(3) Another factor was the period of callus subculture time. Periods, shorter than one year, could improve callus quality and speed up its proliferation. On the contrary, longer than one year, resulted in a drastic reduction of the regeneration proportion of green plantlets, and an increase in albino plants. However, a high frequency of green plant regeneration was obtained by selecting suitable genotypes and adjusting plant hormones in culture medium.