Plant Sex Determination

Plant sex determination in cannabis refers to the genetic and environmental mechanisms that govern whether a plant develops as male, female, or hermaphroditic. Cannabis is dioecious in wild populations, meaning individual plants typically express either male (pollen-producing) or female (pistillate) flowers, though environmental stress can trigger hermaphroditic expression in either sex. Sex determination is controlled by chromosomal factors (XY in most cultivated varieties) and influenced by photoperiod, temperature, and nutrient conditions during early vegetative growth. Understanding sex expression is fundamental to breeding programs, as breeders selectively stabilize either male parents for pollen production or female plants for seed or flower cultivation. Growers also employ techniques like photoperiod manipulation and environmental control to encourage or suppress male development,

Breeders working with dioecious populations use deliberate sex selection to create true-breeding female lines, male stud plants for crosses, and feminized seed stocks. Stability of sex expression under varying environmental conditions is an important trait criterion when evaluating parent plants for commercial and stable genetic lines.