well, we could reasonably infer that there is a way to manipulate the sex of cannabis plants by silencing or intentionally expressing a gene. for example, we can make a plant hermaphrodite intentionally with things like colloidal silver to produce male sex parts from a female plant and produce fem seeds. So there is one of two things happening here, a gene is either being silenced or a silent gene is being expressed that would otherwise be non functional due to the lack of a Y chromosome.
in this study, though it is from 1998, the researchers were able to isolate a karyotype of
C. sativa https://www.jstage.jst.go.jp/article/cytologia1929/63/4/63_4_459/_pdf and found that cannabis does operate on the XY sex determination system.
so even though the sex determination system is XY, there are other genes that function in the expression of sex parts. just as in humans for example, a person can genetically be male, XY, but lack the SRY gene which results in the inability to express the information on the sex chromosome that initiates the development of male sex organs and characteristics like facial hair, and the result is a female phenotype with a male genotype.
