Genetic Bottleneck

Genetic bottleneck refers to a reduction in a plant population's genetic diversity, typically occurring when a small number of individuals establish a breeding lineage or when seeds are repeatedly selected from a narrow trait pool. In cannabis genetics, bottlenecks commonly arise during strain stabilization, regional adaptation, or when breeders intensively select for single dominant traits (cannabinoid ratio, flower density, terpene profile). While intentional bottlenecks can fix desirable characteristics, they reduce allelic diversity and may increase susceptibility to stress, pest pressure, or environmental sensitivity. Understanding bottleneck effects is critical for breeders maintaining long-term genetic vigor and for seed banks preserving representative genetic material.

Breeders deliberately create mild bottlenecks during line-stabilization to lock in target phenotypes, but sustained or severe bottlenecks narrow the genetic foundation available for future crosses. Recognizing and managing bottleneck cycles helps maintain hybrid vigor, disease resistance, and adaptability across generations.