Classification of a Texan wild grapevine population within the genus Vitis

For the development of improved viticultural rootstocks concerning pest resistance and limestone tolerance, an ex situ germplasm collection of Texan wild grapevine species mainly belonging to Vitis berlandieri PLANCH. was established in Geisenheim, Germany. Within this collection, the population named “Dawn View” (DV) attracted attention for beneficial rootstock properties in breeding and for its phenotypic deviations from the majority of the collection, thus doubting its affiliation to V. berlandieri and further questioning its true species identity within the genus Vitis. In this project, the species position of DV within Vitis was analysed by phenotypic and genetic approaches comparing DV with different wild Vitis species originating from America, Europe and Asia. The phenotypic approach was assessed four shoot tip and 12 mature leaf characteristics. The genetic evaluation included microsatellite (SSR)-analysis and a next generation sequencing (NGS)-based method; double digest restriction-site associated DNA sequencing (ddRADseq). According to our results it can be ruled out that DV belongs to the species V. berlandieri. Out of all evaluated species V. monticola shows the highest similarity to DV, thus allowing allocation of DV to this species. As V. monticola was not widely used in rootstock breeding, DV might represent a valuable genetic resource for future rootstock breeding programs.