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Launch of molecular test for sex determination in cannabis

Agdia announced the release of StudFinder, a molecular diagnostic test for sex determination in cannabis.

Cannabis is a genus of wind-pollinated annual flowering plants that have been used for fiber, food, oil, and medicinal purposes for millennia. The genus Cannabis is indigenous to central and eastern Asia but is now cultivated worldwide. Three species are commonly recognized: C. sativa, C. indica, and C. ruderalis. However, there is a dispute as to whether all three are actually subspecies of C. sativa. All species of cannabis typically produce imperfect flowers and are dioecious. This means flowers have either male reproductive organs produced in panicles or female reproductive organs produced in racemes (buds) on separate plants. Consequently, plants can be referred to as being male or female.

Flowers of the male cannabis plant

Flowers of the female cannabis plant

A significant portion of commercial cannabis production utilizes vegetative or asexual propagation. This methodology cultivates tissue cuttings (clones) taken from female mother plants with recognized phenotypes. This is accomplished on a commercial scale and ensures consistency of the female phenotype and desired traits throughout plant inventories. Nevertheless, every plant variety begins as a seed and carries the potential phenotype of either female or male progenitors; the female-to-male ratio of traditional cannabis plants is approximately 65:35. Cannabis breeders and small-scale producers rely heavily on seeds as their sources of genetic material. Moreover, mother plants can be infected with systemic pathogens such as Hop latent viroid, forcing commercial producers to dispose of inventories and restore propagative stocks from seeds. Ultimately, seeds function as reservoirs of curated plant lineages and can be stored indefinitely when not in cultivation.

Removal of vegetative cutting (clone) from mother plant for propagation

The cannabis plant produces more than 100 terpenophenolic compounds known as cannabinoids, including the psychoactive compound tetrahydrocannabinol (THC). Cannabinoids are produced primarily within glandular trichomes, which are minute secretory hairs on flowers and leaves (Figure 4.). And while both female and male cannabis plants have trichomes, the female plants produce much higher concentrations, percentage of dry weight, of cannabinoids relative to male plants. High percentages of THC in dried cannabis flower products are paramount to burgeoning therapeutic and recreational markets. This makes female plants indispensable for the optimization of THC production and most desirable during the selection of new cultivars, whereas male plants are removed from inventories upon identification.

Trichomes on female cannabis flower

Visual identification of male cannabis plants is not typically accurate until six to eight weeks post-germination. During this time, valuable labor, resources, and canopy space are expended and wasted on male plants destined to be rogued. Therefore, early and accurate identification of male plants is essential to the productivity and profitability of the cannabis production industry.

Agdia's new cannabis sex identification test, StudFinder, targets the Y chromosome DNA in cannabis and can identify male plants as early as the cotyledon stage or five to seven days post-germination. StudFinder utilizes isothermal amplification technology and is the newest addition to Agdia's rapid and portable AmplifyRP XRT product line. AmplifyRP technology promotes the rapid amplification and detection of nucleic acid targets, DNA, or RNA while maintaining a single operating temperature. Moreover, this technology achieves target sensitivity and specificity comparable to qPCR while having clear advantages over detection platforms constrained to laboratory environments.

StudFinder protocol is straightforward and does not require a nucleic acid purification step. Plant tissue samples are incubated in an extraction buffer, and crude liquid extracts are tested directly. Thereafter, the qualitative test result is displayed within 20 minutes. When paired with Agdia's AmpliFire isothermal fluorometer, StudFinder is a user-friendly tool that can be implemented in the field or the lab by personnel with limited experience in molecular diagnostics. "This product's high level of performance and utilitarian adaptability change the game for cannabis growers wanting to optimize productivity and profitability," Agdia says.

AmpliFire portable fluorometer

Agdia states its StudFinder assay was validated against a broad panel of cannabis cultivars and achieved a diagnostic sensitivity of greater than 95%. This assay was developed to be used with cotyledon and true leaf tissue matrices. Please visit the StudFinder webpage to access the full product user guide and validation report.

Agdia's StudFinder assay is the newest addition to the AmplifyRP XRT product line, which now includes 27 products. In addition to StudFinder, Agdia offers AmplifyRP XRT products for detection of Beet curly top virus, Botrytis cinerea, Fusarium oxysporum, Lettuce chlorosis virus, Hop latent viroid and Hop stunt viroid, for a total of six of the most widespread and emerging pathogens affecting the cannabis industry.

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