SUGARBEET GERMPLASM DEVELOPMENT AND INNOVATIVE GENETIC AND MANAGEMENT APPROACHES TO REDUCING LOSSES CAUSED BY PATHOGENS
Location: Northwest Irrigation and Soils Research
Title: Sugarbeet Cultivar Evaluation for Bacterial Root Rot
Submitted to: Journal of Sugarbeet Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 27, 2010
Publication Date: May 13, 2010
Citation: Strausbaugh, C.A., Eujayl, I.A., Foote, P. 2010. Sugarbeet Cultivar Evaluation for Bacterial Root Rot. Journal of Sugarbeet Research. 47:51-64.
Interpretive Summary: Bacterial root rot in sugarbeet is a disease problem that was recently described in the Intermountain West region of the United States. The root rot problem leads to losses in the field, storage piles, and factories. At this time, there are no established management options for this disease problem. Host resistance is usually the most economical and environmentally friendly means to control disease problems, so studies were conducted to establish a selection method for identifying resistance to bacterial root rot in sugarbeet germplasm. The research was successful in establishing methods and parameters for improving host resistance in sugarbeet. Cultivars with improved resistance should lead to less sucrose loss in the field and storage piles, and improve factory efficiency.
Bacterial root rot of sugarbeet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, studies were conducted to establish an assay for identifying host resistance. In 2006 and 2007, 21 commercial cultivars were grown, hand dug, and tested in a petri dish laboratory assay. Root slices were inoculated with L. mesenteroides, incubated at 30°C, and the diameter of the rotted area was measured after 72 and 96 hr. The cultivars were tested in a randomized complete block design with 4 replications. When averaged over both studies, root rot after 96 hr in the commercial cultivars ranged from 14 to 37 mm, while the least significant difference was 5 and 7 mm in 2006 and 2007, respectively. The cultivar ranking between studies was correlated at 72 (r squared = 0.47, P = 0.03) and 96 (r squared = 0.43, P = 0.05) hr. The assay allowed for reliable cultivar separation regardless of whether one, two, three, or four roots were used per replication. The assay should allow host resistance to bacterial root rot to be improved in sugarbeet.