“… 11 How substitution of half the parental genome in the hybrid generates different degrees of leaf size heterosis was found to be attributable to a distinctly increased number of photosynthetic cells due to the expression upregulation degree of cell cycle genes, where the expression change in the F 1 hybrid with high-level heterosis was found to be optimized by superior heterozygous eQTL accumulation. 11 In maize, through a design of multiple linked F 1 populations containing 42,840 F 1 hybrids and genome-wide association study, an instance of epistasis was revealed where one recessive, deleterious maternal allele, Brachytic2 , repressed the favorable Ubiquitin3 locus in the maternal lines, while the paternal allele alleviated this repression and thus recovered plant height and ear weight in hybrids. 10 The genomic architectures of heterosis in rice, maize, wheat, and other crops were also characterized using the population-based method, 6 , 7 , 12 , 13 , 26 , 27 , 44 which uncovered many novel loci functioning in heterosis via dominance, overdominance, and epistasis.…”