A molecular marker set combining a retrotransposon insertion and SSR polymorphisms is useful for assessing diversity in Vitis

Abstract

Molecular markers, based on DNA polymorphisms, are useful tools for identifying individuals, establishing phylogenetic relationships, managing collections of genetic material or assisting breeding. In the present study, we developed a marker set to differentiate Vitis species, grapevine varieties or clones belonging to the same variety. This novel marker set combines, in four PCR amplifications, the presence/absence of a remarkable retrotransposon, Tvv1-Δ3460, inserted at its single locus and the SSR polymorphism present within its two LTRs. By studying a collection of Vitaceae accessions, we showed the prevalence of two allelic forms of Tvv1-Δ3460 - one of which was partially truncated - in Vitis species. Out of the twenty-five studied Vitis species, the insertion of a Tvv1-Δ3460 element was detected in twenty, including Vitis vinifera. The homozygous vs heterozygous state of the element insertion was determined by amplifying the empty site. Additionally, each Tvv1-Δ3460 LTRs included a microsatellite sequence useful for designing markers based on LTR length. The LTR-SSR markers distinguished most of the fifty-two cultivars and revealed polymorphism within five of the seven varieties studied.