Researchers at University College Dublin have identified a genetic “switch” that determines the sex of cannabis plants — and found that the same system may also be present in hops.
Published in New Phytologist, the study identifies a specific region of the X chromosome that influences whether cannabis plants develop as male, female, or both.
“It was known for quite a while that female cannabis plants possess two X chromosomes and male plants carry an X and a Y chromosome, but there are thousands of genes on those chromosomes,” said Associate Professor Rainer Melzer, senior author of the study. “Which of those genes determines whether a plant becomes male or female was unknown.”
Within a small stretch of DNA, researchers identified three closely linked genes that work together to control male and female development, according to a press release.
Using genetic mapping, genome sequencing and gene expression analysis, the UCD team, working with international partners, identified this region — known as Monoecy1 — as a major control point for sex expression. The same key genes were also found in hops in a corresponding region of the X chromosome.
This suggests the genetic “switch” existed before cannabis and hops diverged around 28 million years ago.
“We were quite surprised when a lot of evidence pointed to a small region on the X chromosome as a key driver of sex determination, because in many other species, including humans, the Y chromosome determines sex,” said Matteo Toscani, a Ph.D. student at UCD and first author of the study.
The findings could have important agricultural applications, particularly for crops such as hops and cannabis, where female plants are more economically valuable.
Read the full story at Seed World
