Definition of heterosis in English:



  • The tendency of a crossbred individual to show qualities superior to those of both parents.

    Also called hybrid vigor
    • ‘The fundamental genetic and physiological causes of heterosis remain poorly understood in plants after nearly a century of exploitation in crop improvement.’
    • ‘Genetic background, heterosis, and sex differences can all have profound effects on chiasma and recombination frequencies.’
    • ‘With overdominance, unlike alleles are postulated to result in a stimulating effect, so that genetic heterozygosity per se produces heterosis.’
    • ‘Traditionally the issue of heterosis has been posed in genetic terms such as dominance and overdominance.’
    • ‘The fixation of deleterious mutations may be a general explanation for heterosis in crosses between ecotypes, despite alternative overdominance interpretations.’


Early 20th century: from Greek heterōsis alteration from heteros other.