Effects of gibberellins GA4 and GA7 on flowering in Scots pine grafts.

[摘要] Ethanolic sprays of GA or GA on 9-year old Scots pine ( L.) grafts, repeated four times during the shoot elongation period, resulted in a statistically significant increase in female flowering one year after the treatment. Of the two compounds, GA seemed to be somewhat more efficient, yielding 47 female strobili/100 shoots vs. 36 and 6 strobili/100 shoots in GA and control treatments respectively. The mixture of GA and GA compounds was also applied and seemed to have an effect intermediary to those of the pure compounds. However, due to the limited amounts of material, none of the differences between the gibberellins could be statistically confirmed. Male flowering frequencies were also too low to allow any firm conclusions, but the numerical results suggested that the purified gibberellins may promote male and female flowering in different ways.47Pinus sylvestris4747