Incomplete Dominance

Incomplete dominance is a non-Mendelian inheritance pattern in which neither parental allele fully masks the other, resulting in offspring phenotypes that differ from both parents. In cannabis breeding, this pattern can produce intermediate trait expression—such as plants displaying pigmentation, leaf shape, or growth characteristics that represent a blend between parental genetics rather than a simple dominant/recessive outcome. Breeders working with this inheritance mode often observe wider phenotypic variation within single-generation crosses, as heterozygous individuals express measurable combinations of both parental traits. Understanding incomplete dominance helps predict trait segregation across generations and is relevant when stabilizing complex quantitative traits. This differs from codominance, where both alleles express equally and distinctly rather than blending.

Breeders leveraging incomplete dominance can select for intermediate phenotypes or use segregating populations to isolate rare trait combinations. Recognition of this pattern aids in explaining unexpected F1 uniformity and designing multi-generation stabilization schedules.