中文摘要：

为建立以玉米幼苗为外植体的高效再生体系，克服幼胚取材的限制，本研究选取萌发3d的玉米幼苗作为供体材料，研究其不同部位的再生能力。分别研究了种子萌发时的光照条件，N6培养基中Ca^2＋度，及6个不同基因型对芽尖和根尖愈伤组织诱导率和分化率的影响。结果显示，黑暗条件下萌发的幼苗，其芽尖和根尖更适合作为外植体，诱导培养基中添加终浓度为5mmolL^-1的CaCl2时的愈伤组织诱导率最高，不同基因型的玉米愈伤组织的诱导率和分化率存在差异，但影响趋势相同，且同一基因型的不同外植体形成的愈伤组织形态相似，分化率也相似。最后结论是黑暗条件下萌发3d的齐319和鲁原92的幼苗，可以代替玉米幼胚作为外植体用于组织培养研究。

英文摘要：

Currently, immature embryo is the most widely used explant for maize regeneration and transformation. However, this material source is restricted by geographical condition, developmental stages and the growing season. Here, we isolated different parts the of three-day-old seedlings to study their regeneration capacity, aiming to establish an alternative efficient regeneration system for maize. Using the shoot tips and primary root of three-day-old seedlings of maize germinated in dark and light as ex- plants, the effects of illumination, genotype, and different concentration of Ca^2＋ in the induction medium on the primary callus induction rate and seedling differentiation rate were analysed. The result showed that shoot tips and the root tips derived from seedlings germinated in the dark were better source materials. Root materials isolated from the mature zone of the primary root could not be weed to induce primary callus. The primary callus induction rate was the highest when 5 mmol L^-1 of Ca^2＋ was added in the induction medium. The callus induction and differentiation rates of both explants from the six different genotypes were very different. However, the effect of the genotype on primary callus induction and differentiation rates from the two explants was con- sistent. The differentiation rate and the morphology of the callus from the two explants of the same genotype were also similar. From above, we propose that the 3-day-old seedlings of Qi 319 and Luyuan 92 germinated in the dark have the potential to re- place the immature embryos for maize tissue culture in the future.