用不同浓度的秋水仙素溶液处理苹果的栽培品种嘎拉试管苗的离体叶片，发现以０．５％的秋水仙素溶液处理４ｄ效果最佳，诱变频率达５６．１％。诱变后获得的四倍体植株在形态学和细胞学上均发生了明显变异。与对照株比较，变异株茎矮、粗壮、节间短、叶片厚、叶色浓绿；叶背面的气孔体积增大，单位面积气孔数目减少、茸毛数量增加；染色体数目加倍，２ｎ＝４ｘ＝６８（对照２ｎ＝２ｘ＝３４），细胞核核仁数目增加。梢端组织学切片证明，变异株中同质突变体的频率达７３％。 Treated with different concentrations of colchicine solution, the in vitro leaves of Gala plantlets of apple cultivars were treated with 0.5% colchicine solution for 4 days. The mutagenesis frequency reached 56.1%. The tetraploid plants obtained after mutagenesis showed obvious morphological and cytological variations. Compared with the control plants, the mutant plants were short stalk, stout, short internodes, thick leaves and dark leaf color. The stomatal volume on the back of leaves increased, the number of stomata per unit area decreased and the number of stamens increased. The number of chromosomes doubles, 2n = 4x = 68 (control 2n = 2x = 34), the number of nuclear nucleolus increased. Histological sections of the tip demonstrated that the frequency of homogenous mutants in the mutants reached 73%.