Aneuploidy

Aneuploidy refers to an abnormal number of chromosomes in a plant cell—a deviation from the typical diploid (2n) state found in most cannabis plants. In cannabis, aneuploidy can occur naturally through meiotic errors during seed formation or be induced experimentally through chemical treatment. Aneuploid plants often exhibit reduced vigor, altered morphology, or sterility, making them generally undesirable in breeding programs. However, some breeders have documented aneuploid individuals within segregating populations, particularly triploids (3n) or other polyploid derivatives. Understanding aneuploidy is important for seed producers and cultivators aiming to maintain genetic stability and prevent unintended chromosomal irregularities in their lines.

Breeders monitor for aneuploidy as a quality-control concern in seed stocks, since aneuploid offspring typically underperform agronomically. Some breeders working with polyploidy intentionally generate aneuploid intermediates as part of hybrid or triploid breeding protocols, though such plants require careful selection and are not standard practice in most breeding operations.