Fig. 9

Model explaining the heterosis of seedling biomass in canola hybrids. In the early stages of seedling growth, the photosynthetic and plant hormone signal transduction pathways along with the high parental dominance expression of key genes correlated with cell size, ultimately lead to the differential expression of hybrids in terms of leaf length and leaf width relative to their parents. Subsequently, we observe heterosis in the biomass. Moreover, the expression levels of these vital genes are different in strong and weak hybrids, which also explains the phenotypic heterogeneity of strong and weak hybrids