| Botanical principle that the offspring of a cross displays greater mass, yield, disease resistance, or other desired characteristic than its parents. The hybrid is heterozygous with respect to the parents, meaning it has multiple versions of the same gene. (It has multiple alleles on its homologous chromosomes). Based on research by Gregor Mendel with pea plants. Related to the idea that that when plants of the same strain are repeatedly crossed (inbred), recessive (usually undesirable) traits are reinforced, while crossing different strains demotes the recessive traits. | 
