Genomic architecture of biomass heterosis in Arabidopsis

Significance Heterosis, the phenotypic superiority of a hybrid over its parents, has been extensively exploited in agriculture to improve biomass and yield. Despite its great agricultural importance, the genetic components underlying heterosis remain largely unclear. Here, we characterize the genomic architecture of heterosis in Arabidopsis that have not undergone domestication and identify hundreds of genetic loci that collectively contribute to biomass heterosis using genome-wide association studies. The functional investigation of candidate genes and transcriptomic analysis in representative hybrids suggest that the accumulation of superior genes involved in basic biological processes and the repression of stimulus-responsive genes in hybrids contribute to biomass heterosis in Arabidopsis , thus providing a comprehensive understanding of the genetic bases of heterosis in natural populations of plant species.