Lots of cash ride on cannabis gender, so Sonoma County startup launches quick testing
The odds are good that if you have ever come across a cannabis plant, it was a female.
That is because like people, cannabis plants come in separate male and female forms. Unlike us, however, the sexes are not equal.
That's because the female varieties of cannabis produce its most grower-valued products — like flower buds containing mind-altering THC in marijuana plants and prized CBD in hemp plants. Both marijuana and hemp fall under the classification of cannabis.
With that in mind, a small but growing group of companies are using DNA analysis to determine the sex of plants earlier and faster than before.
Without it, producers would have to wait weeks until the plants exhibit sex-specific traits, perhaps another way that pot and people aren't quite the same.
And one company, Sebastopol-based LeafWorks, said they can do it better than anyone else.
One way cannabis, humans, and other organisms are similar, however, is that cannabis plant cells contains either two X-chromosomes if they are female or an X and a Y-chromosome in the case of males, according to Kerin Law, co-founder of LeafWorks.
Law and co-founder Eleanor Kuntz, who met during their graduate studies at the University of Georgia, said they have developed a highly accurate method to determine if there is a Y-chromosome — and hence, the frowned-upon male plant — present.
They said their method works between seven to 10 days of planting, allowing growers to uproot the unwanted males and replace them with profitable females without wasting resources cultivating until the plant's sex is visible to the naked eye, which can take weeks.
Who said gender reveals have to be lighthearted?
'It saves not just the time; it's also all the labor associated with keeping that plant happy,' Kuntz said of the benefit of early male eradication.
For growers, males also pose a threat to yields of flower or bud, the part of the female plant where its THC or CBD content is concentrated. That is because males produce pollen that, when mixed with the prized female flower, causes the plants to reproduce by seeding.
'If you only have a certain amount of square footage to devote to a certain number of plants and half of your plants end up being male, then you have to remove them before they produce pollen,' she said. 'You want the bud; you want the flower. And if the pollen gets on the flower, it turns to seed, [and] it's not valuable in the same way.'
How exactly Kuntz and Law perform that test in their lab and what sections of the plant's chromosomes they look at remains a trade secret.
But they said much of their work to develop the process focused on mapping — 'sequencing' — parts of the plants' genetic structure to determine which DNA building blocks were specific to male plants, allowing for their early identification.
Because scientists do not fully understand that genetic structure, pioneers in this field like Law and Kuntz must do original research to which determine DNA building blocks, are present only in male cannabis plants.
One of LeafWorks' competitors, Medical Genomics, based in Beverly, Massachusetts, offered additional insight into how the process of early-stage plant sexing can be done.
Kyle Boyar, West Coast field application scientist at Medical Genomics, said his company looked at hundreds of male and female varieties of cannabis to determine their DNA structures or sequences, and to nail down which DNA building blocks were present only in male plants.
Recent technology has also allowed them to understand the structure of each of the 10 cannabis chromosomes, allowing them to double check their work and verify the sequences they identified are located on the Y-chromosomes, Boyar said.
While he added this work involved looking at the genetic sequences of hundreds of male and female strains of cannabis, Kuntz and Law said their test was more accurate than competitors because they had collected a library of almost 1,000 male varieties and between 4,000 and 5,000 females as examples.
They studied their genetic structures and chromosomal DNA sequences to ensure '100 percent that the things that we're [testing] are on the Y-chromosome and only the Y-chromosome,' Law said.
Kuntz likened the process to looking for the trait of blue eye color in men.
'If you look at five males and you're looking at blue eye color, you might just get one version,' she said. She noted the more examples you look at the more versions of blue eye color you are likely to come across.
She added when you expand the pool of examples, in this case the 1,000 males, 'you get a more robust idea of whether the match you think you're making is truly aligned, truly associated with the trait and in this case, the trait would be having a Y-chromosome.'
The competitors also differ in how they perform that actual tests.
Medical Genomics offers a mail order kit that can be purchased for $5 per sample. First, a farmer collects a tiny leaf sample that is then boiled to extract the DNA. Two components, one colored, are added to the DNA samples and heated to amplify the male-specific DNA strands in a separately available machine. In less than an hour, the machine produces a result for each sample — pink for female, yellow for male.
LeafWorks sends farmers a chemically treated card that dissolves the plant matter until just the DNA is left. At the laboratory, the company then performs a proprietary test.
Law and Kuntz did divulge that they test DNA sequences on different parts of the chromosomes that are physically far apart to avoid false positives or negatives.
LeafWorks charges $20 per sample or $80 a card, but offers bulk-pricing incentives.