Fett Mauro Sander, Mariot Roberta Fogliatto, Avila Eduardo, Alho Clarice Sampaio, Stefenon Valdir Marcos, de Oliveira Camargo Flávio Anastácio
Soil Science Department, Agronomy Faculty, Federal University of Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves, 7712, Porto Alegre, Rio Grande do Sul, CEP 91540-000, Brazil.
Setor Técnico-Científico, Superintendência Regional do Departamento de Polícia Federal no Rio Grande do Sul, Avenida Ipiranga, 1365, Bairro Azenha, Porto Alegre, Rio Grande do Sul, CEP 90160-093, Brazil.
Int J Legal Med. 2019 Mar;133(2):373-384. doi: 10.1007/s00414-018-1940-3. Epub 2018 Oct 15.
It is known that Cannabis in Brazil could either originate from Paraguay or be cultivated in Brazil. While consumer markets in the North and Northeast regions are maintained by national production, the rest of the country is supplied with Cannabis from Paraguay. However, the Brazilian Federal Police (BFP) has exponentially increased the seizure number of Cannabis seeds sent by mail. For this reason, the aim of the study was to assess the 13-loci short tandem repeat (STR) multiplex system proposed by Houston et al. (2015) to evaluate the power of such markers in individualization and origin differentiation of Cannabis sativa samples seized in Brazil by the BFP. To do so, 72 Cannabis samples seized in Brazil by BFP were analyzed. The principal coordinate analysis (PCoA) and probability identity (PI) analysis were computed. Additionally, the Cannabis samples' genotypes were subjected to comparison by Kruskal-Wallis H, followed by a multiple discriminant analysis (MDA). All samples analyzed revealed a distinct genetic profile. PCoA clearly discriminated the seizure sets based on their geographic origin. A combination of seven loci was enough to differentiate samples' genotypes, and the PI for a random sample is approximately one in 50 billion. The Cannabis samples were 100% correct as classified by Kruskal-Wallis H, followed by an MDA. The results of this study demonstrate that the 13-loci STR multiplex system successfully achieved the aim of sample individualization and origin differentiation and suggest that it could be a useful tool to help BFP intelligence in tracing back-trade routes.
众所周知，巴西的大麻要么原产于巴拉圭，要么在巴西种植。北部和东北部地区的消费市场由国内生产维持，而巴西其他地区则由来自巴拉圭的大麻供应。然而，巴西联邦警察（BFP）查获的通过邮件寄送的大麻种子数量呈指数级增长。因此，本研究的目的是评估休斯顿等人（2015年）提出的13个位点的短串联重复序列（STR）复合系统，以评估此类标记在巴西联邦警察查获的大麻样品个体化和产地鉴别中的效力。为此，对巴西联邦警察在巴西查获的72份大麻样品进行了分析。计算了主坐标分析（PCoA）和概率同一性（PI）分析。此外，对大麻样品的基因型进行了Kruskal-Wallis H检验，随后进行了多重判别分析（MDA）。所有分析的样品都显示出独特的遗传特征。PCoA根据地理来源清楚地区分了查获的样品组。七个位点的组合足以区分样品的基因型，随机样本的PI约为五千亿分之一。通过Kruskal-Wallis H检验和MDA对大麻样品进行分类，正确率为100%。本研究结果表明，13个位点的STR复合系统成功实现了样品个体化和产地鉴别的目的，并表明它可能是帮助巴西联邦警察情报部门追溯贸易路线的有用工具。
