THE GENETIC-BASIS FOR VARIATION IN THE CONCENTRATION OF PHENOLIC GLYCOSIDES IN SALIX-SERICEA - CLONAL VARIATION AND SEX-BASED DIFFERENCES

Many members of the Salicaceae produce phenolic glycosides, and the co ncentrations of these are known to vary among plants. We determined wh ether the concentration of two phenolic glycosides, salicortin and 2'- cinnamoyl salicortin, varied among clones of Salix sericea and whether this variation was due to the sex of the plant. We tested 16 clones, seven male and nine female, for variation in glycoside concentration a nd several plant growth rate parameters. The concentrations of salicor tin and 2'-cinnamoyl salicortin varied extensively between clones and exhibited broad-sense heritability. Clones also varied in growth rate. Interestingly, none of these clone effects were due to differences be tween male and female plants. There was no correlation between shoot l ength and chemistry, although it appears that faster growing clones of ten produce lower concentrations of the two phenolic glycosides. We di scuss these findings in relation to current theory concerning plant al location to growth and defense.