Abstract

The effects of plant growth regulator combinations on the contents of vindoline, catharanthine and vinblastine were investigated by short-term spray on an ornamental and medicinal plant Catharanthus roseus (L.) during the blooming period for commercial use. The combination groups such as ethylene (0.1 mM) + chlormequat chloride (0.1 mM), salicylic acid (0.1 mM) + chlormequat chloride (0.1 mM) and salicylic acid (0.1 mM) + ethylene (0.1 mM) + chlormequat chloride (0.1 mM) resulted in a significant increase of the three alkaloids contents. The combination groups salicylic acid (0.1 mM) + ethylene (0.1 mM) + chlormequat chloride (0.01 mM) and salicylic acid (0.1 mM) + ethylene (0.1mM) + chlormequat chloride (1 mM), affected vindoline and catharanthine contents but had no effect on vinblastine. Among the combination treatments, salicylic acid (0.1 mM) + ethylene (0.1 mM), ethylene (0.1 mM) + chlormequat chloride (0.1 mM) and salicylic acid (0.1 mM) + ethylene (0.1 mM) + chlormequat chloride (0.1 mM) could significantly increase the vinblastine content by 209% at 48 h, 246% at 48 h and 213% at 24 h respectively. Thus compared to the single PGRs treatments, the combination treatments increase alkaloids accumulation more effectively. The result may provide a method for increasing TIAs in C. roseus for industrialized production.

Key words: Catharanthus roseus, plant growth regulator combination, vindoline, catharanthine, vinblastine, blooming period.