The largest genetic study of cannabis genomes has revealed important considerations for farmers selecting high quality hemp seeds. Researchers are using whole-genome resequencing of 110 seed accessions obtained worldwide to shed light on the origins and genetic pathways of cannabis. This strategic data collection initiative will help answer hemp growers’ questions about hemp seeds developed to cultivate crops high in CBD and low in THC. Researchers can trace cannabis strains back to their origins and study genetic pathways so that seed breeders can extract and combine compounds for a desired aroma, taste, effect, and terpene profile.
The genome study resulted in the identification of several potential genes separating hemp from cannabis and noting differences in physical features such as growth patterns and cellulose amounts. The study also provided evidence that CBD and THC biochemically “compete” during selection for increased fiber production or psychoactive properties.
This study has implications for hemp growers who must always be cognizant of remaining below a .3% THC level as mandated by the 2018 Farm Bill. The genome analysis found that many chemical profiles were inconsistent, as did a separate research study, “Genomic and Chemical Diversity of Commercially Available High-CBD Industrial Hemp Accessions”. The study also discovered discrepancies between the actual chemical composition of samples and their certificate of analysis (COA). Little genetic consistency in accessions despite sharing the same strain name, and an active THCa synthase gene which potentially leads to higher THC levels. Despite the steps taken in cultivation practices to minimize environmental stress and manage soil conditions, genetics are the key factor in making a crop prone to testing hot or above the .3% limit. The findings emphasize the importance of scrutinizing seed quality and genetics prior to purchasing and planting hemp seeds.
This study identified hemp industry infrastructure challenges to cultivating hemp within the .3% THC limit such as the lack of a hemp seed certification program, a lack of cannabinoid research, and complicated state and federal policies. Genetic mapping can help promote best practices in agriculture, research, and cannabis policy development.