Mapping Rhizoctonia Crown and Root Rot resistance from FC709-3 using new genomic resources.

Abstract

Rhizoctonia solani is the fungal pathogen that causes Rhizoctonia Crown and Root Rot (RCRR) on sugar beet (Beta vulgaris). This devastating disease generates millions of dollars of yield loss throughout most sugar beet growing regions. Tapping decades of RCRR prebreeding lines from the USDA-ARS Fort Collins, CO, we have selected the most resistant accession, FC709-2. This accession was further enhanced for RCRR resistance using three additional cycles of mass selection followed by the selection of a highly resistant individual plant which was used for single seed descent (FC709-3). A single FC709-3 plant was selected for PacBio HiFi and Dovetail Omni-C sequencing to generate a highly contiguous de novo genome assembly. Using this purpose-built chromosome scale genome assembly, we aim to map the genetic underpinnings of RCRR resistance in FC709-3 using RNA-seq, QTL mapping and bulk segregant analysis.