A loss of vigor amongst offspring occurring when closely related individuals mate, resulting from the expression of numbers of deleterious genes in a homozygous state and from a generally low level of heterozygosity.
loss in vigor associated with inbreeding. Occurs most frequently in cross-pollinated or clonally propagated species. Caused by accumulated effects of 1) deleterious recessive alleles combined into a homozygous trait or 2) loss of the vigor associated with a positive interaction of two different alleles at a single locus.
Reduction, in inbred individuals, of the mean value of a character (usually one correlated with fitness).