Objective: To determine the phenotypic plasticity between fertilized (F) and unfertilized (UF) Q. variabilis seedlings developed in a nursery using small, medium, and large seeds.
Design/methodology/approach: By analyzing the phenotypic traits of growth (height and diameter at root collar) and root and stem dry biomass, plasticity indices and allocation patterns were assessed, and phenotypic traits in which the interaction effect of the seedling fertilization and seed size was observed.
Results: The results showed significant differences (p-value≤0.05) in the growth and biomass traits except for the root dry biomass, and significant differences were found both in the fertilization and seed size factors and in the fertilization and seed size interaction in phenotypic traits. For plasticity, all traits showed marked changes in response to the nutrient application, and small seeds had the highest plasticity indices. With respect to phenotypic change indices, medium seeds reached the highest values (0.94 for height and 0.92 for diameter). Large seeds recorded the highest index for root dry biomass (1.01), and medium seeds had the highest values of plasticity for stem dry biomass (0.81). Allometric differences were observed (intercepts were 1.8374 and 3.4956, and slopes were 4.0943 and 1.7038 for UF and F seedlings, respectively), and variations in the study factors (fertilization and seed size).
Limitations on study/implications: In order to improve the survival of plants in the field it is necessary to use seeds with high quality.
Findings/conclusions: Fertilization of Q. variabilis seedlings increases their biomass production, which allows for greater growth and survival compared to unfertilized ones.