an increase in the performance of hybrids over that of purebreds, most noticeably in traits such as fertility and survivability.

Increased vigor or growth associated with a combination of two dissimilar parents. Caused by the masking of deleterious recessive alleles or the positive interaction of two dissimilar alleles at the same locus.

The increased growth or production exhibited by the first generation over the average of its two parent breeds. It is usually expressed as a percentage.

The increase in vigor of hybrids over their parental inbred types; also known as heterosis.

(syn. heterosis) increased vigor of hybrid offspring when compared to either parent

Unusual growth, strength, and health of heterozygous offspring from two less vigorous homozygous parents.

The production of an exceptionally vigorous and/or productive hybrid progeny from a directed cross between two pure-breeding plant lines. A synonym for heterosis.

Also heterosis; the superiority of the heterozygote over the homozygote for a specific trait; or the tendency of a cross between two distinct populations to be more productive or more fit than either of the parent strains.

(HV) Heterosis. Superiority of a crossbred individual relative to the average performance of purebred parents included in the cross.

The adaptive superiority of the heterozygous GENOTYPE with respect to one or more characters in comparison with the corresponding HOMOZYGOTE.