Micropropagation has several advantages over conventional vegetative propagation methods, but it is limited by genotype responsiveness. We assessed the effect of age of the mother-tree and the time of explant collection on culture initiation, as well as the multiplication ability and effect of different nutrient media and plant growth regulators on silver birch genotypes. Explants collected from 1‐year‐old trees (66%) and explants collected in spring (64–67%) developed a significantly (both p < 0.001) higher proportion of shoots than those from 15‐year‐old trees (39%) and those collected in mid-summer (31%) and autumn (29%), respectively. In a stabilised culture, the length of the main shoot varied from 1.3 to 7.8 cm between genotypes, and the multiplication rate ranged from 1.0 to 6.8 shoots per explant. Hyperhydrated shoots were present in 17 out of 50 clones, and, among the clones, ranged from 14 to 50%. Cultures on the Murashige and Skoog basal medium had a higher multiplication rate than cultures on a Woody Plant Medium, and the application of zeatin provided better results than 6‐benzylaminopurine. The difference between cytokinin types was 11–29% for the multiplication rate and 21–29% for the length of the main stem. The highest multiplication rate was obtained using a zeatin concentration of 0.5 mg L⁻¹. However, better shoot growth and proliferation had a significant positive relation to shoot hyperhydration (all p < 0.001). Therefore, a medium with an optimal balance between the multiplication rate and the number of hyperhydrated shoots should be carefully selected.

与传统的营养繁殖方法相比，微繁殖具有几个优势，但受到基因型响应能力的限制。我们评估了母树的年龄和外植体收集时间对培养起始的影响，以及不同营养培养基和植物生长调节剂对白桦基因型的繁殖能力和影响。从一岁树上采摘的外植体（占66％）和春季采摘的外植体（占64-67％）显着增长（均p <0.001）的芽比例分别高于15岁树的芽（39％）和仲夏的芽（31％）和秋天的树（29％）。在稳定的培养中，基因型之间主茎的长度在1.3到7.8 cm之间变化，每个外植体的繁殖率在1.0到6.8根之间。在50个克隆中的17个中存在超水化芽，其中克隆的比例为14％至50％。与木本植物培养基上的培养相比，Murashige和Skoog基础培养基上的培养具有更高的繁殖率，并且与6-苄基氨基嘌呤相比，玉米蛋白的应用效果更好。细胞分裂素类型之间的差异为繁殖率11–29％，主茎长度为21–29％。使用0.5 mg L ^-1的玉米素浓度可获得最高的增殖率。然而，更好的芽生长和增殖与芽水合作用显着正相关（所有p  <0.001）。因此，应谨慎选择在繁殖率和高水合芽数之间具有最佳平衡的培养基。