Evaluation of resistance to Cercospora leaf spot (CLS) and tolerance to sugarbeet root maggot (SBRM) in wild sea beet (Beta vulgaris ssp. maritima (L.) Arcang) accessions

Authors: Chu, Chenggen; TEHSEEN, MUHAMMAD MUSSAU - North Dakota State University; Preister, Lisa; BRANCH, ERIC - North Dakota State University; BOETEL, MARK - North Dakota State University; BURT, EMMA - Minn-Dak Farmers Cooperative; CHANDA, ASHOK - University Of Minnesota Crookston; Ramachandran, Vanitharani; Bolton, Melvin; LI, XUEHUI - North Dakota State University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/17/2025
Publication Date: 12/14/2025
Citation: Chu, C.N., Tehseen, M.B., Preister, L.S., Branch, E., Boetel, M., Burt, E., Chanda, A., Ramachandran, V., Bolton, M.D., Li, X. 2025. Evaluation of resistance to Cercospora leaf spot (CLS) and tolerance to sugarbeet root maggot (SBRM) in wild sea beet (Beta vulgaris ssp. maritima (L.) Arcang) accessions. Crop Science. 65 (6):e70206. https://doi.org/10.1002/csc2.70206.
DOI: https://doi.org/10.1002/csc2.70206

Interpretive Summary: Cercospora leaf spot (CLS) disease and sugarbeet root maggot (SBRM) cause significant sugarbeet yield loss in the United States. Identification and utilization of resistance sources from wild sea beet, the progenitor of all cultivated beet biotypes (sugarbeet, fodder beet, and table beet), will not only enhance sugarbeet resistance to pests and diseases but also bring in new genetic variations that benefit sustainable improvement. This research evaluated the resistance/tolerance in a core collection of sea beet germplasm under multiple environments to CLS and SBRM, respectively, and identified some accessions showed resistance to CLS and/or tolerance to SBRM. Based on the investigation of genetic similarities between sea beet accessions and cultivated sugar beet biotypes, some sea beet accessions that are resistant to CLS or tolerant to SBRM will have greater potential for introducing new genetic variation into sugar beet. This study identified valuable genetic resources for improving sugarbeet.

Technical Abstract: Cercospora leaf spot (CLS) disease, caused by the fungus Cercospora beticola Sacc., and sugarbeet root maggot (SBRM, Tetanops myopaeformis [von Röder] [Diptera: Ulidiidae]) cause significant sugarbeet (Beta vulgaris L. [Caryophyllales: Amaranthaceae]) yield loss in the United States. Identification and utilization of resistance sources from wild sea beet (B. vulgaris ssp. maritima (L.) Arcang), the progenitor of all cultivated beet biotypes (sugarbeet, fodder beet, and table beet), will not only enhance sugarbeet resistance to pest and diseases but also broaden its genetic base for sustainable improvement. Using 300 core accessions that were selected based on phylogenetic analysis of publicly available B. maritima collections in the United States, this research evaluated their resistance/tolerance to CLS and SBRM, respectively, under multiple environments. A set of 42 accessions consistently exhibited resistance to CLS, of which 18 accessions belonged to sub-populations that are genetically distinct from cultivated sugarbeet. Another set of 32 accessions showed minor root damage caused by SBRM under different environments and were considered tolerant, of which 19 accessions are genetically more diverse from cultivated sugarbeet. In total, 11 accessions showed resistance to both CLS and SBRM. These accessions will be valuable resources to diversify sugarbeet resistance to CLS and SBRM, and those showing distinct genetic distances from cultivated sugarbeet will also have a higher potential to introduce novel genetic variations to broaden the sugarbeet genetic base.