The New Cranberry Wisconsin Research Station: Renovation Priorities of a ‘Stevens’ Cranberry Marsh Based on Visual Mapping, Genetic Testing, and Yield Data

Cultivar contamination is a common issue in commercial cranberry production. Unknown or unwanted cranberry genotypes are found in commercial cranberry beds that are intended to be a single uniform genotype. Identification of contamination and the impact of contamination remain crucial issues for the cranberry industry to maintain long-term high productivity. To address this issue, tissue samples were taken from the former commercial beds of the new Wisconsin Cranberry Research Station (WCRS) for genetic fingerprinting analysis. The goal of this collection was to analyze the 10 beds for genetic uniformity to determine if any should be maintained or replaced, and to assess the accuracy of visual perception of genetic contamination in the field. A total of 288 DNA samples were collected in the 10 cranberry beds, and the ‘Stevens’ cultivar represented 180 samples or 69% of the 261 samples expected to be ‘Stevens.’ Therefore, the genotype contamination in the ‘Stevens’ beds was 31% overall. Overall, visual differentiation was accurate in distinguishing between genotypes and detecting large areas of contamination. A yield analysis was conducted along with the genotypic uniformity assessments, and a significant correlation was found between the 2017 yield of the beds and their level of genetic contamination. This study demonstrates the usefulness of genetic uniformity testing and mapping for cranberry bed management and renovation decision-making.