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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sugarbeet Research » Research » Publications at this Location » Publication #431002
Research Project: Improving Sugarbeet Productivity and Sustainability through Genetic, Genomic, Physiological, and Phytopathological Approaches

Location: Sugarbeet Research

Title: Evaluation of sugar beet breeding lines for resistance to Rhizoctonia crown and root rot in northwest Minnesota, 2025

Author
item LIEN, AUSTIN - University Of Minnesota Crookston
item Chu, Chenggen
item CHANDA, ASHOK - University Of Minnesota Crookston

Submitted to: Plant Disease Management Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2026
Publication Date: 2/17/2026
Citation: Lien, A.K., Chu, C.N., Chanda, A.K. 2026. Evaluation of sugar beet breeding lines for resistance to Rhizoctonia crown and root rot in northwest Minnesota, 2025. Plant Disease Management Reports. 27:007. https://doi.org/10.1094/PHP-01-26-0007-PDMR.
DOI: https://doi.org/10.1094/PHP-01-26-0007-PDMR

Interpretive Summary: Rhizoctonia crown and root rot (RCRR) is one of the most common root diseases affecting sugar beet production in Minnesota, North Dakota and Michigan. Using varieties resistant to RCRR is the most efficient way to control the disease. In previous growing seasons, several breeding lines developed by the USDA-ARS Sugarbeet Research Unit at Fargo, ND had shown a high or moderate level of RCRR resistance. This research evaluated the lines again in a RCRR field nursery at the University of Minnesota, Crookston, MN, which confirmed the high level of RCRR resistance in a few breeding lines and proved that they can serve as a useful source of resistance for sugar beet breeding.

Technical Abstract: Rhizoctonia crown and root rot (RCRR) is a serious fungal root disease for sugar beet (Beta vulgaris ssp. vulgaris L.) caused by fungus Rhizoctonia solani. Based on RCRR resistance evaluation conducted in previous seasons, fifteen sugar beet breeding lines were evaluated again this year in field nurseries at University of Minnesota, Crookston, MN with four replications included. Ground barley seeds infested with Rhizoctonia solani isolate AG 2-2 were spread directly over sugar beet crowns at a rate of 15 g per row for inoculation. Roots were arbitrarily selected from each replication and rated for the severity of RCRR using a 0 to 10 scale system with a 10% incremental increase per each unit of rating. A mixed-model analysis of variance was performed with breeding line defined as the fixed factor and replication as the random factor. The overall RCRR index values for breeding lines 24N0038, 24N0039, 24N0036, and 23N0024 were numerically less than the moderately resistant check (C912) and significantly less than the moderately susceptible cultivar (C793). The results validated that resistance in four lines is comparable to or greater than the moderately resistant cultivar, proved these RCRR resistant breeding lines are useful sources of resistance for future breeding efforts.