Untranslated leader region polymorphism of Tvv1, a retrotransposon family, is a novel marker useful for analyzing genetic diversity and relatedness in the genus Vitis

Abstract

Grapevine retrotransposons belonging to the Tvv1 family share a single, highly conserved open reading frame but differ by their untranslated leader (UTL) region, which is highly variable in size. Amplification of the UTL region of Tvv1 elements from 94 Vitaceae accessions reveals that each of them shows a unique pattern of UTL-derived bands, which is inherited in progenies but conserved between clones vegetatively propagated. The overall organization of genetic diversity of the Vitaceae at the inter and intraspecific level and relatedness among accessions described by UTL-derived bands was compared to those obtained using 15 microsatellite loci. Both fingerprinting methods show a similar grouping of Vitis vinifera accessions but UTL-based fingerprinting more accurately isolates the muscadine grapes from the American and Asian Vitis. Finally, sequence analysis of seven UTL regions determines that their size variation is essentially caused by large deletions/insertions within the internal region, whereas flanking regions are more conserved. UTL-based fingerprinting could be considered as a novel marker system specific of the genus Vitis; moreover, as this multiband genotype is stable between clones it is suitable to be used as a "DNA barcode" for Vitis identification.