Plant Sex Determination

Plant sex determination in cannabis refers to the genetic mechanisms that establish whether a plant develops as female (pistillate), male (staminate), or hermaphroditic. Cannabis is typically dioecious, with sex chromosomes (XY system) determining phenotype, though environmental stress can trigger hermaphroditism in genetically female plants. Understanding sex expression is foundational to breeding, as only female plants produce the cannabinoid-rich flowers sought in cultivation. Breeders track sex stability across generations to identify lines prone to hermaphroditism or to deliberately create feminized seed stocks. Seed type classification—regular, feminized, or autoflowering—directly reflects how breeders manipulate and stabilize sex determination traits.

Breeders working with sex determination focus on selecting for stable female expression to reduce unwanted male or hermaphroditic plants in production crops. Feminized seed development relies on induced female-to-female breeding or colloidal silver techniques to reverse sex expression, a controlled application of sex determination principles.