A Cannabis sativa STR genotype database for Australian seizures: forensic applications and limitations

A genetic database was established with the aim of documenting the genetic diversity of Cannabis sativa in Australia for future utilization in forensic investigations. The database consisted of genotypes at 10 validated short tandem repeat loci for 510 plants representing drug seizures from across Australia and 57 fiber samples. A total of 106 alleles and 314 different genotypes were detected. All fiber samples exhibited unique genotypes while 55% of the drug samples shared a genotype with one or more samples. Shared genotypes were mostly found within seizures; however, some genotypes were found among seizures. Statistical analysis indicated that genotype sharing was a consequence of clonal propagation rather than a lack of genetic resolution. Thus, the finding of shared genotypes among seizures is likely due to either a common supplier, or direct links among seizures. Notwithstanding the potential intelligence information provided by genetic analysis of C. sativa, our database analysis also reveals some present limitations.