Agroecología

martes, 6 de noviembre de 2018

A plant biodiversity effect resolved to a single genetic locus
Samuel E. Wuest and Pascal A. Niklaus

There is now pervasive evidence of positive effects of biodiversity on plant community productivity and functioning. Although some advances have been made linking diversity effects to functional trait variation, progress towards a mechanistic understanding remains slow - in part because biodiversity effects are emergent complex properties of communities, and mechanisms might differ between communities or environmental conditions. Without a mechanistic understanding, however, the advancement of ecological theory as well as applications in agriculture are impeded. Here, we analyse non-additive interactions between divergent Arabidopsis accessions in experimental plant communities. By combining concepts and designs from ecology and plant breeding with genetic methods, we have identified a major effect locus at which allelic diversity promotes community productivity. In further experiments with near-isogenic lines, this diversity effect locus was resolved to a single region representing less than 0.3% of the genome. Using plant-soil-feedback experiments, we demonstrate that allelic diversity causes genotype-specific soil legacy responses in a subsequent plant generation. This suggests that asymmetric interactions of plants with soil-borne factors drive niche complementarity and that the impacts of allelic diversity can extend across generations. In summary, this work shows that positive diversity effects can be linked to single Mendelian factors, and that complex community properties can have simple causes. This may pave the way to novel breeding strategies, which focus on phenotypic properties that do not manifest themselves at the individual level, but only at a higher level of biological organisation.