Sex determination in cannabis operates through an XY chromosome system, where male plants carry XY sex chromosomes and female plants are XX. This genetic mechanism is fundamental to cannabis biology, as the species is predominantly dioecious with separate male and female plants. The Y chromosome carries male-determining genes that trigger stamen development, while the absence of Y (XX genotype) results in pistillate flower formation.
However, sex expression in cannabis is more complex than simple XY determination. Environmental factors including photoperiod stress, nutrient deficiency, and temperature extremes can induce hermaphroditism even in genetically stable populations. Some landrace populations show higher rates of hermaphroditism than others, suggesting genetic variation in sex stability. Traditional farmers in regions like the Western Himalayas often rogue hermaphrodite plants to maintain population quality, representing artificial selection against hermaphrodite-promoting alleles. Understanding sex genetics is crucial for seed production, breeding programs, and maintaining landrace population integrity.
