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Current Category » Principles of Plant Breeding

Comparison of Dominance and Overdominace Theories of Heterosis


Dominance Hypothesis

Overdominace Hypothesis




Effect of inbreeding

Inbreeding tends to decline in vigour

Also leads to decline in vigour

Out breeding

Out breeding restores vigour

Out breeding restores vigour

Parental diversity

Heterosis is associated with parental diversity.

Also associated with parental diversity


Heterosis is controlled by genes

Also controlled by genes.




Causes of heterosis

Heterosis results due to masking effect of dominant desirable allele or over harmful recessive alleles. 

Heterosis results due to complementation between divergent alleles.

Current Category » Principles of Plant Breeding