Karyotyping

Karyotyping is the cytogenetic technique used to visualize and analyze the complete chromosome set of a cannabis plant. This process involves staining chromosomes and arranging them in standard order to determine chromosome number, structure, and morphology. Cannabis plants typically display a diploid karyotype (2n=20), though polyploid forms with higher chromosome counts exist in breeding populations. Karyotyping provides breeders with objective data on genetic ploidy level and chromosomal integrity, which can correlate with plant vigor, fertility, and trait expression across generations.

Breeders use karyotyping to confirm ploidy in polyploid breeding programs, verify chromosome stability in stabilized lines, and identify chromosomal abnormalities that may affect seed viability or phenotypic consistency. Establishing accurate karyotypes is particularly relevant when developing triploid or tetraploid cultivars for specific agronomic traits.