Effect of Applying Commercial Gibberellins on Seed Germination of Chrysanthemum coronarium L.

Chrysanthemum coronarium L. is a very common species native to the province of Murcia, SE Spain, which flowers towards the end of winter. Although the plant produces a large number of seeds, the germination percentage tends to be very low. Since several studies have found that the application of gibberellic acid improves this percentage; the object of this work was to ascertain the effectiveness of commercial gibberellins on the germination percentage in C. coronarium. In the first experiment, the seeds were treated with novagib (R) (GA(4/7) 1%), clemencuaje (R) (GA(3) 1.6%), vip (R) (6- benzyladenine 1.9%+GA(4/7) 1.9%) or gibberellic acid (GA(3) 90%), at concentrations of 250, 500, 1,000, 1,500, 2,000, 2,500, 3,000 and 3,500 mg L-1. The results showed that novagib produced the highest germination percentage (24%). In a second experiment, binary combinations of these products were assayed but no synergistic effect was observed. A third experiment studied the effect of the gibberellins on intact and on naked seeds. The germination percentage in the naked seeds, whether or not treated with gibberellins, reached 90%. We conclude that the dormancy of C. coronarium seeds is regulated by coat imposed dormancy and not to the physiological processes regulated by gibberellins.