INTER- AND INTRAGENOTYPIC COMPETITION UNDER ELEVATED CARBON DIOXIDE IN ARABIDOPSIS THALIANA

摘要: The consequences of elevated CO2 on plant growth have been well studied individual plants. response a more complex system with several plants interacting is less understood-a situation that limits our capacity to predict the natural communities. In this study we analyzed effect enrichment intergenotypic competition in Arabidopsis thaliana. Seeds five genotypes collected from different populations were used. Each genotype was cultivated pure stand and mixture each other four two conditions (ambient elevated). At harvest time, fitness estimated by number fruits seeds produced per plant. current levels C02, performed better than mixture. Kin selection, associated low seed dispersal autogamous reproductive regime A. thaliana, invoked explain these positive responses among similar genotype. Surprisingly, high-CO2 atmosphere (700 ,iwL/L) reverse observed: mixtures stands. Positive frequency- dependent selection under ambient concentration became negative which could lead easily maintenance genetic variation. This hypothesis tested simple model competition. equilibrium, simulation did not show coexistence concen- tration. However, allows predictions about evolutionary trajectories high- conditions. will maintain most their ability grow should be selected increasing CO2.