Sex determination in cannabis is the genetic and developmental process that establishes whether a Cannabis plant develops as male, female, or, in some cultivated forms, monoecious. Cannabis is normally dioecious: pollen-bearing (male) and seed-bearing (female) flowers form on separate individuals, and sex is set by a pair of heteromorphic sex chromosomes. Females carry two X chromosomes (XX) and males an X and a Y (XY), so the male is the heterogametic sex and the Y is transmitted only through pollen.
Chromosomal sex, fixed at fertilisation, is distinct from sex expression: the male or female character of the flowers a plant actually produces. Sex expression is labile: hormonal, chemical and environmental signals can shift a plant toward the opposite sex's flowers without altering its chromosomes, and a genetically female (XX) plant induced to shed pollen transmits only X-bearing gametes.
The distinction is central to cannabis cultivation and breeding. … read more →
