Organelle DNA haplotypes reflect crop-use characteristics and geographic origins of Cannabis sativa

Comparative sequencing of cannabis individuals across 12 chloroplast and mitochondrial DNA loci revealed 7 polymorphic sites, including 5 length variable regions and 2 single nucleotide polymorphisms. Simple PCR assays were developed to assay these polymorphisms, and organelle DNA haplotypes were obtained for 188 cannabis individuals from 76 separate populations, including drug-type, fibre-type and wild populations. The haplotype data were analysed using parsimony, UPGMA and neighbour joining methods. Three haplotype groups were recovered by each analysis method, and these groups are suggestive of the crop-use characteristics and geographical origin of the populations, although not strictly diagnostic. We discuss the relationship between our haplotype data and taxonomic opinions of cannabis, and the implications of organelle DNA haplotyping to forensic investigations of cannabis.     

Developmental validation of a Cannabis sativa STR multiplex system for forensic analysis

A developmental validation study based on recommendations of the Scientific Working Group on DNA Analysis Methods (SWGDAM) was conducted on a multiplex system of 10 Cannabis sativa short tandem repeat loci. Amplification of the loci in four multiplex reactions was tested across DNA from dried root, stem, and leaf sources, and DNA from fresh, frozen, and dried leaf tissue with a template DNA range of 10.0-0.01 ng. The loci were amplified and scored consistently for all DNA sources when DNA template was in the range of 10.0-1.0 ng. Some allelic dropout and PCR failure occurred in reactions with lower template DNA amounts. Overall, amplification was best using 10.0 ng of template DNA from dried leaf tissue indicating that this is the optimal source material. Cross species amplification was observed in Humulus lupulus for three loci but there was no allelic overlap. This is the first study following SWGDAM validation guidelines to validate short tandem repeat markers for forensic use in plants.