Understanding the mechanisms of sex determination in the dioecious species Cannabis sativa L. is crucial for cultivators. This knowledge is important due to the high value of female inflorescences in cannabinoid production, the need for seeds in hemp-grain production, and the variation in fiber quality between sexes in fiber hemp. Comprehending these mechanisms can also enhance breeding programs aimed at developing new varieties with desirable traits.
Sex expression in C. sativa appears to be primarily controlled by genetic mechanisms through an XY chromosome system, although environmental factors that influence plant hormones also contribute to sex expression. While the genetic mechanisms governing sex determination have not been fully elucidated, there are useful molecular tools available for sex identification during the early stages of plant development.
Various chemical treatments that influence plant hormones have been developed to force female plants to produce male flowers or male plants to produce female flowers. These treatments enable female plants to produce pollen, allowing them to fertilize themselves or other females and generate seeds devoid of a Y chromosome, known as feminized seeds.
While monoecious individuals appear to have XX chromosomes, the differences between those monoecious X chromosomes that have not yet been assembled and those from females remain unknown. The Y chromosome, which is the largest in the genome, possibly due to repetitive content and rearrangements, has yet to be assembled, leaving the genes it harbors unidentified. The genetic factors that determine sexual strategy and expression in C. sativa are still undetermined.
Baek, Yousoon & Vergara, Daniela. (2025). A review of sexual strategies in Cannabis sativa L. under genomic and environmental controls. Agrosystems, Geosciences & Environment. 8. 10.1002/agg2.70050.
Source: Research Gate