Abstract
Sugarbeet (Beta vulgaris L. ssp. vulgaris Doell.) was originally selected from white fodder beet in the 1780s and is now an important source of sucrose production. The relatively short history of sugarbeet leads to its narrow genetic base and limited genetic resources for sugarbeet trait improvement. Exploring gene sources for sustainably improving sugarbeet is urgent to increase sugar productivity as well as enhance crop resilience to climate change. The USDA-ARS sugarbeet genetics program at Fargo, ND has evaluated 1,936 sugarbeet germplasm that are largely maintained by the U.S. National Plant Germplasm System (NPGS). Genetic diversity analysis using SNPs covering the whole genome identified wild sea beet (B. vulgaris ssp. maritima (L.) Arcang., the progenitor of all cultivated beet) accessions that were genetically distinct from cultivated beet, indicating their great potential to broaden the sugarbeet genetic base. Evaluation of disease and insect resistance in the sea beet identified accessions showed a high level of resistance to Cercospora leaf spot (causal organism: Cercospora beticola) and sugarbeet root maggot (Tetanops myopaeformis). Our ongoing study aims to detect genome regions of sea beet associated with resistance to diseases and insects, and then develop markers for efficient introgression of these traits. Taken together, our research identified important genetic resources that can be used to increase sugarbeet sustainability and will facilitate the development of new varieties to improve sugar productivity.