Abstract: The polyploid breeding technique was used to induce polyploid of Dendrobium devonianum, an orchid occurring in the tropics of Yunnan with ornamental and medicinal values . The materials for polyploid breeding were in vitro seedlings of diploids . The polyploid plants could be induced in a short time with colchicines as mutagen . It resulted in the best inductive effect to use 0 . 03% colchicines to deal with the in vitro seedlings of diploids for 24 hours . The polyploid plants were different from those of diploids in morphology , stoma diameter , chromosome numbers, and DNA fingerprints . The in vitro seedlings of polyploid plant showed advantageous characteristics such as thicker stems and leaves . It is a successful case to apply polyploid breeding technique into the tropical orchid breeding in China .

Key words: Dendrobium devonianum

摘要： 采用多倍体育种技术, 对云南的野生热带兰花齿瓣石斛(Dendrobium devonianum) 进行多倍体诱导试验。利用秋水仙素作为诱导剂, 对二倍体试管苗进行诱导, 在短期内培育出多倍体植株。用0.03%的秋水仙素处理齿瓣石斛丛生芽24 h , 其诱导效果最好。观察结果显示: 多倍体齿瓣石斛材料在形态、气孔直径、染色体数目上都有变化。DNA 指纹图谱等方面都发生了显著的改变。多倍体齿瓣石斛试管苗出现了植株粗壮、叶片增厚等优良性状。此研究是多倍体育种技术在我国热带兰花育种中的一次成功尝试。

关键词: 齿瓣石斛, 多倍体FONT