Spring mobilization of storage 32P in gingko trees

The labelled phosphorus was supplied to the roots of 1-year-old gingko (Gingko biloba L.) trees during dormant period in the glass house and the mobilization of stored 32P determined in the following early growing season. 32P was detected in all growing tissues, the level of radioactivity being greatest in the root tissues over the 4-week sampling period. At dormant period, only 0.44% of 32P was found in storage tissues (bark, wood and bud) although the accumulation of 32P occurred especially in root tissues. During early growing season, 32P was transported from root tissues to new growing tissues (buds). Eight percent of the initial 32P in storage tissues was transported to new growing tissues. During this period, the 32P in the bud tissues increased about 12 fold. (author)