Nitrogen availability, growth, carbon partition and resin content in Grindelia chiloensis

The objective of this work was to test whether resin production is linked to nitrogen availability as predicted by the CNBH. Plants of G. chiloensis were grown in a greenhouse under four nitrogen availability conditions (0, 1.5, 3.0, and 6.0 mM of N) generated using a modified Hoagland solution. Structural and functional characters were measured. Leaf resin and root total non-structural carbohydrate content (TNC) were higher in plants grown with low nitrogen availability, whereas assimilation rate was slightly affected, in accordance with predictions. Under low nitrogen availability, shoot biomass, and leaf-stem ratio were lower. Resin composition was only slightly affected by nitrogen availability, suggesting that this character is under strong genetic control.