白桦组培再生系统的研究(Ⅱ)——影响因素及培养程序

Study on Tissue Culture and Regeneration System of Betula platyphylla Suks (Ⅱ):Influence of Factors on Culture and Culture Protocols

在“白桦（Ｂｅｔｕｌａｐｌａｔｙｐｈｙｌａｓｕｋｓ）组培再生系统的研究（Ⅰ）”的基础上，以展叶顶芽、休眠腋芽和种子为最初外植体，通过初始培养获得无菌苗后，选取无菌苗的不同部位作外植体，如：茎节、嫩枝、愈伤组织等，经过诱导培养、分化培养及生根培养，形成再生植株。研究了培养基、激素种类及浓度、无性系、外植体类型、蔗糖浓度对诱导及生根的影响，提出白桦组培的最佳条件及程序。最佳无性系的一个外植体，经三次继代培养增殖达３０００株，最佳培养基上的生根率达９５％以上，Ⅰ、Ⅱ级苗的移栽成活率达９０％。

Following the paper“Study on Tissue Culture and Regeneration System of Betula platyphylla Suks(Ⅰ)”,a thorough study was made. In this paper, shoot tip, dormant axillary bud and seed were used as initial explants. After sterile shoots were obtained, different explants from them were cultured and regenerated into plantlets. Various media and hormones, hormone concentrations, clones, explants and sucrose concentrations were tested in induction and rooting culture. The best medium and hormone combination were suggested and regeneration protocol was put forward. An explant from the best clone which has the highest propagation rate can produce nearly 3 000 shoots after 3 subcultures. The best rooting rate is over 95% and the survival rate of the first and second grades of seedlings reaches 90%.