TY - JOUR T1 - Genetic Characterization of Pierce’s Disease Resistance in a <em>Vitis arizonica/monticola</em> Wild Grapevine JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. DO - 10.5344/ajev.2022.22021 SP - ajev.2022.22021 AU - Karla Gabriela Huerta-Acosta AU - Summaira Riaz AU - Alan Tenscher AU - M. Andrew Walker Y1 - 2022/09/20 UR - http://www.ajevonline.org/content/early/2022/09/09/ajev.2022.22021.abstract N2 - Pierce’s Disease (PD) is a bacterial disease that threatens vineyards across the US and Mexico. Genetic resistance against this disease has been achieved using the resistance locus PdR1, which was found in a wild grapevine from Mexico. In order to broaden the genetic base, we aimed to identify additional unique sources of resistance. The objective of this study was to characterize PD resistance in accession b46-43, a PD resistant wild grapevine from Texas. The manifestation of PD resistance in b46-43 is different from b43-17, with even cane lignification, minor leaf scorch and minimum bacterial growth. It was hypothesized that b46-43 possibly carry resistance that differ from the PdR1 locus in b43-17. A total of 318 seedlings from population 14399 were evaluated for PD resistance and genotyped. The framework genetic map was developed and a quantitative trait locus (QTL) analysis was carried out. The QTL analysis identified a major locus that explained 55.5% of the phenotypic variation on chromosome 14, at the genomic position PdR1 was mapped in earlier studies. No minor loci were identified on other chromosomes. The rarity of additional loci indicates that PD resistance may have a common origin and it is widespread as a result of gene flow. ER -