Effects of gibberellic acid as a gametocide on different genotypes of German Chamomile (Matricaria recutita [L.] Rauschert)

The objective of the present research was to determine statistically before made observations on reactions of Chamomile after treatment with gibberellic acid undertaken to find a feasible way of chemical castration to create maternal lines as a base for hybrid progeny. Chamomile plants of three cultivars were set up in a split plot design, with treated and untreated parts. Four traits: 'percentage affected capitula', 'seeds per capitulum', 'percentage of germination' and 'percentage infertile pollen' were valuated, twice per plant. Analyses showed a significant effect of treatment on pollen viability and a strong tendency on the visible affection of capitula, but no influence on number of seeds or germination rate. Neither did cultivars show any influence, nor did an interaction between cultivar and treatment appear. According to the aim to find a suitable method to generate male sterile maternal lines, the reactions, affecting male, but not female fertility, seem to be highly appreciated, but the repeated spray application in a necessarily sensible stage of flower development and a reduction of pollen viability of only about 10% constrain the practicability.