XVI International Botanical Congess

In this work, attention was devoted to the uptake and transport of 2,4-D, which seems to be one of the most important factors influencing the induction of embryoge- nic cultures in Norway spruce. To study the uptake of 2,4-D in the radicle, hypocotyl and cotyledons of embryo we used 14C-2,4-D. After first 8 hours of uptake, the content of 14C-2,4-D was the highest in the radicle, but after about 16 hours all three parts of the embryo showed almost equal levels of 14C-2,4-D. The level of 14C-2,4-D in cotyledons was the highest after 24 hours, but after 32 hours it decreased, probably as the result of polar transport of 2,4-D. 14C-activity per 1mg of fresh embryo weight decreased in time till 72 hours, when it rapidly increased probably as the result of the starting proliferation processes (grant No. 522/96/K186).