Abstract:

Investigations were carried out on the effects of colchicine treatment on growth and polyploid induction of rhizomes of Cymbidium sinense ‘QiJianBiaMo’. The results showed that colchicine treatment had severe toxic and lethal effects on the rhizomes, and in the range of concentration of colchicine and duration of treatment adopted, the higher the concentration of colchicine and the longer the duration of treatment were, the stronger the toxic and lethal effects were. Chromosome doubling was found in all rhizomes pretreated with colchicine, while, the efficiency depended on the concentration of colchicine and the duration of treatment. Tetraploids were obtained only in the treatment of 0.01%×3 d, with the induction rate being 11.11%. In other treatments, only mixoploids were produced with the induction rate between 0.00 % and 19.44%. The tetraploid rhizome was rounder in growth tip and larger in diameter, and the regenerated tetraploid plant was more sturdy and compacted in appearance with harder leaves and thicker roots compared to the diploid one.