The study of botanic DNA analysis on forensic applications
| Autor: | Tsai Li-Chin, 蔡麗琴 |
|---|---|
| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 Forensic botanical comparison can be hampered by the lack of appropriate DNA databases. In this study, we report on the use of the trnL intron and the trnL-trnF IGS in the chloroplast genome (cpDNA) and establish a DNA sequence database for plant species identification. The database comprises 365 individual sequences representing 79 families, 206 genera and 264 species. These plant species can be grouped to species level using both sequence and length polymorphisms at these loci. In blind trial testing, most of the blind samples matched their respective species from our local DNA database. Cluster analysis with Neighbor joining method of the two DNA regions from 80 samples of this study were constructed and clustered to both family and genus. The sequence database described in this study can be used to identify plant species using DNA sequences of the two loci and illustrates its value in plant species identification. Bidens pilosa L.with barbed fruits is dispersed via animal species resulting in a widespread distribution and therefore frequently collected when attached to evidential samples during criminal investigation. In this study, 161 specimens were used from these varieties comprising 11 different populations and 7 samples of Bidens biternata were included as an out-group control. DNA fragments of all samples at the trnL intron and trnL-trnF IGS loci of cpDNA, ITS1, 5.8S and ITS2 of nrDNA were amplified and sequenced. From the sequence types of the 5 loci, trnL intron, ITS1, ITS2 and 5.8S were found to be useful markers to differentiate Bidens biternata and Bidens pilosa. There were 84 haplotypes at the 5 loci from 161 specimens. Among 84 haplotypes, B. radiata could be almost differentiated from the varieties of Bidens pilosa using these 5 loci. It showed that the genetic diversity of nrDNA sequence was higher than that of cpDNA from the data of the number of polymorphic sites (S), number of haplotypes (H), gene diversity (Hd), nucleotide diversity (π) and genetic diversity (θ). From the results of the analysis of molecular variance (AMOVA), there are more than 50 % variance contributed by the variance of “within populations” in the loci of nrDNA and cpDNA. The gene flow between var. radiata and var. minor or var. pilosa showed lower than those between var. minor and var. pilosa, it indicated the significant hybridization phenomenon between var. minor and var. pilosa which naturalized earlier than var. radiata. In the case report of suspect seed samples, species analysis was performed by DNA analysis using the trnL-trnF IGS of cpDNA, and the ITS1 of nrDNA. Based on these analyses, it was determined that all seeds were from the species Cannabis sativa. The system established in this study provides a robust tool for cannabis seed identification. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|