Following the sequencing of a growing number of plant genomes and with the availability of more and more powerful computational tools, DNA sequences are becoming the major source of information in understanding the evolutionary and genetic relationship among plant species. The importance of a comparative sequence analysis is clearly evident in studies aimed at clarifying the taxonomic and phylogenetic relationships at interspecific level. Since 2003 several authors proposed and demonstrated that the nucleotide content of a single gene can be sufficient for the discrimination and the identification of animal species. The experimental reliability and the general applicability of this approach, known as “DNA barcoding”, has been first assessed using the mitochondrial gene CO1 encoding for the subunit I of the cytochrome oxydase .The term “DNA barcoding” refers to a DNA-sequence based identification system that may be constructed of several loci used together as complementary unit to define a specific haplotype. A species can thus be unequivocally identified on the basis of single nucleotide polymorphisms (SNPs) or insertions/deletions (In/Dels) in the most conserved regions of one or a few selected genes. A DNA barcoding approach based on mitochondrial genes is not feasible in plants because of their much slower rate of evolution compared to animals.. This research was aimed at developing molecular diagnostic tests able to screen the plant biodiversity and univocally identify species belonging to the Salix L. genus. For this purpose we assessed the level of sequence divergence (SNP and In/del polymorphisms) among 22 willow species in two chloroplast putative barcode loci to determine which of them maximize species identification when combined as a barcode. Willow species belonging to Humboldtiana and Salix subgenera were clustered apart, supporting species separation on the basis of bio-geographical and morphological traits, whereas species of subgenera Caprisalix and Chamaetia were unrecognizable on the basis of two chloroplast intergene spacers, this is probably due to their frequent hybrid origin. Nuclear barcode sequences, able to identify recombination events have to be evaluated.

Identification of Salix L. entities by DNA barcoding.

LUCCHIN, MARGHERITA;SALMASO, MARZIA;PAIERO, PAOLO
2011

Abstract

Following the sequencing of a growing number of plant genomes and with the availability of more and more powerful computational tools, DNA sequences are becoming the major source of information in understanding the evolutionary and genetic relationship among plant species. The importance of a comparative sequence analysis is clearly evident in studies aimed at clarifying the taxonomic and phylogenetic relationships at interspecific level. Since 2003 several authors proposed and demonstrated that the nucleotide content of a single gene can be sufficient for the discrimination and the identification of animal species. The experimental reliability and the general applicability of this approach, known as “DNA barcoding”, has been first assessed using the mitochondrial gene CO1 encoding for the subunit I of the cytochrome oxydase .The term “DNA barcoding” refers to a DNA-sequence based identification system that may be constructed of several loci used together as complementary unit to define a specific haplotype. A species can thus be unequivocally identified on the basis of single nucleotide polymorphisms (SNPs) or insertions/deletions (In/Dels) in the most conserved regions of one or a few selected genes. A DNA barcoding approach based on mitochondrial genes is not feasible in plants because of their much slower rate of evolution compared to animals.. This research was aimed at developing molecular diagnostic tests able to screen the plant biodiversity and univocally identify species belonging to the Salix L. genus. For this purpose we assessed the level of sequence divergence (SNP and In/del polymorphisms) among 22 willow species in two chloroplast putative barcode loci to determine which of them maximize species identification when combined as a barcode. Willow species belonging to Humboldtiana and Salix subgenera were clustered apart, supporting species separation on the basis of bio-geographical and morphological traits, whereas species of subgenera Caprisalix and Chamaetia were unrecognizable on the basis of two chloroplast intergene spacers, this is probably due to their frequent hybrid origin. Nuclear barcode sequences, able to identify recombination events have to be evaluated.
2011
Actas del Tercer Congreso Internacional de las Salicaceas en Argentina
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/2572540
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