This is how we chill from ’23 ’til: breeding cold hardy grapevines for unprecedented and unpredictable climate challenges

Recent interest in grapevine cultivation in North Dakota, USA drives the ongoing establishment of commercial vineyards and wineries. While production in North Dakota and the Upper Midwestern US is focused on cold hardy grapevines, varying levels of cold damage to vines occurs frequently in fall, winter, and spring; this damage ultimately reduces vineyard yields and sustainability. Beyond this, North Dakota’s short growing season can frequently restrict the final ripening characteristics of fruit for wine, specifically as measured by high acid levels in the grape berries. Due to the inconsistent production of commercial cultivars in North Dakota, breeding efforts were established through the North Dakota State University Grape Germplasm Enhancement Project (NDSU-GGEP). The NDSU-GGEP targets the development of consistent yielding, disease resistant, cold hardy grapevines that are early ripening to achieve low levels of acid for the region. Through traditional plant breeding methods, starting in 2011, hundreds of unique crosses were performed for the purposes of cultivar development (regional elite × regional elite) and germplasm development (extreme cold hardy parent × high quality fruit parent). The NDSU-GGEP’s first multi-site replicated trials were established in 2016 following elite seedling material selected for hardiness and fruit quality in the conditions of Fargo, ND; from these plots, selected grapevines are being advanced to serve grower needs. Top performing NDSU-GGEP lines were intercrossed in the field and greenhouse immediately upon phenotypic selection giving rise to a second wave of germplasm material. Current objectives for the NDSU-GGEP remain focused on integrating yield components and early ripening traits into cold hardy backgrounds. With the recent inclusion of molecular markers in the program, these goals have expanded to include the development of predictive selection methods such as genomic selection and QTL development for core traits necessary for survival in North Dakota’s viticultural climate.