High resolution melting curve analysis revealed SNPs in major cannabinoid genes associated with drug and non-drug types of cannabis

Cannabis sativa L. has a long history of cultivation as food, fibre, medicine and recreational drugs. Production of high tetrahydrocannabinol (THC) plants for narcotic use (drug type) is illegal and under control in most countries. In contrast, cultivation of low THC plants (fibre type, also known as ‘industrial hemp’) is promoted in many countries. The determination of C. sativa L. chemotypes is based on the major cannabinoids content, THC, cannabidiol (CBD) and cannabinol (CBN). The THC:CBD content ratio is a candidate marker for differentiation of the fibre and drug type of cannabis. The ability to accurately characterize the cannabinoid chemical phenotype (chemotype) is crucial for the development of specific C. sativa cultivars for pharmacological, hemp fibre or seed end-use. High resolution melting (HRM) curve analysis is used as a rapid and effective mechanism for detection of single-nucleotide polymorphisms in plants. In this report, we developed a HRM protocol for differentiation of drug and non-drug cannabis plants. According to the results, HRM analysis based on single-nucleotide polymorphisms in THCAS gene is an accurate method to differentiate the drug type of cannabis which could be used for the control of legal and illegal cannabis cultivation