EN
In order to analyze changes in biomass allocation patterns across genetically structured populations where plants are competing for access to light, we performed glasshouse experiment with controlled genetic identity of competitors. Clonal replicates of 17 Lamium maculatum (L.) genotypes were grown in three treatments: control (low competition for light availability), intraclonal and interclonal competition. It was shown that competition between genetically unrelated individuals (interclonal treatment) was the most stressful environment for Spotted Dead Nettle. Results of allometry analyses, based on standardized major axis (SMA) mathematical procedure, have shown the smallest differences in relative investment to sexual reproduction between larger and smaller individuals when competing with unrelated plants. Our results indicate that allometric relationships between vegetative and reproductive traits could be strongly affected by genetic relatedness of competing plants.