Abstract Jake UretskyM. Andrew Walker

A Preliminary Study of Taxonomic and Geographic Relationships among Accessions of Vitis berlandieri and Associated Taxa

Jake Uretsky and M. Andrew Walker* 
*Department of Viticulture and Enology, University of California,
Davis, CA 95616 (awalker@ucdavis.edu)

Endemic to the limestone soils in central Texas, Vitis berlandieri (currently V. cinerea var. helleri) was incorporated into rootstock breeding programs after scions grafted to early rootstock cultivars exhibited lime-induced iron chlorosis in calcareous soils. Despite its historical and viticultural significance, very few V. berlandieri accessions are conserved in germplasm repositories, and information regarding the genetic and phenotypic diversity in the species is sparse. In 2015 and 2016, we collected V. berlandieri from central Texas and sampled V. cinerea from east Texas. Our objectives were three-fold: (1) expand ex situ V. berlandieri germplasm; (2) characterize V. berlandieri genetically and geographically, particularly in relation to V. cinerea; and (3) examine phenotypic diversity in V. berlandieri. Here, we report an analysis of the population structure of V. berlandieri and associated species collected throughout Texas and northern Mexico. The analysis included acces-sions obtained from several germplasm repositories and new accessions. To reduce sampling bias, we included samples of V. mustangensis, which is found across the range of V. berlandieri and V. cinerea within the collection areas, but is morpho-logically, phenologically, and genetically distinct from both species. Our initial results show strong support for population structure within the sampled accessions and indicate a distinct V. berlandieri subpopulation in south-central Texas and V. cinerea subpopulations in eastern Texas and northern Mexico.

Funding Support: California Grape Rootstock Improvement Commission, California Grape Rootstock Research Foundation, American Vineyard Foundation, CDFA Improvement Advisory Board, California Table Grape Commission, Louise Rossi Endowed Chair in Viticulture, and support for Jake from the David E. Gallo Award, the Horace O. Lanza Scholarship, and the ASEV Michael Vail Scholarship