Effect of Colchicine on Chromosome Doubling in Codonopsis lanceolata

Abstract

The present study was performed to investigate the effects of the colchicine concentrations on chromosome doubling for producing of tetraploid plants of Codonopsis lanceolata, and its effect on plant morphology. A total of 180 individuals germinated from 16 treatment groups, were exposed to various concentrations (0.05-1.0% w/v) of colchicine for different soaking duration (3-24 hour). The highest numbers of tetraploid plants (3) were observed from the lowest concentration of colchicine (0.05%), and one (1) tetraploid plant was obtained from the 0.5% concentration group with a 6 hour treatment. However, no tetraploid individual was observed in any other treatment groups. The plant height of the diploid (18.1 ㎝) was slightly shorter than that of the tetraploid (13.4 ㎝). The fresh weight of the main root in the diploid (0.5 g) was four-fold higher than the tetraploid (2.2 g). The colchicine-treated plant regeneration rate in C. lanceolata was decreased when the plants were subjected to high concentration of colchicine. In particular, the highest number of tetraploid plants (5 and 3) was obtained from the lower concentration (0.05% and 0.1%) of colchicine for 6-hour treatment, which were a higher rate (29.4% and 30%) of regenerated tetraploid plants than other regenerated plants. As in the seed treatment result, the plant height of the diploid was significantly higher (10.4 ㎝) than tetraploid. The higher morphological changes were observed comparatively from tetraploid plants than the diploid.