Improving the resistance of Kuras to late blight with new genomic technologies

The Danish potato industry centres around starch potato varieties, covering approximately 45,000 ha, of which the starch variety Kuras occupies 27,000 ha due to its advantageous properties, such as high yield, (original) strong resistance to late blight, and drought tolerance. Unfortunately, Kuras has lost its resistance to late blight, making it highly susceptible and requiring increased fungicide use. Instead of replacing Kuras, we propose enhancing its resistance. Our project suggests R-gene rotation to extend the effectiveness of R-genes. To achieve this, we will create Kuras variants with distinct R-genes using precision breeding tools and determine the optimal rotation strategy to prolong the lifespan of these R-genes. By doing so, our aim is to reduce pesticide usage in Kuras cultivation and, consequently, within the potato industry. To realize this objective, our plan includes selecting effective and robust R-genes and mploying precision breeding to obtain kuras lines with combinations of several R-genes identified from wild accession; validating the durability of novel cultivars developed in this project; conducting histological studies on resistance mechanisms and response timing in the most robust novel varieties; and demonstrating the robustness of the novel varieties in the feld.