Browse Journals
Volume 62, Number 1, February 2025
Peer Reviewed Manuscripts
Utilizing Boron to Improve Sugarbeet Yield, Quality, and Cercospra Leaf Spot Management
Abstract View Article
Cercospora beticola, the causal pathogen of Cercospora leaf spot (CLS), reduces sugarbeet yield up to 40% when not managed appropriately. Plant defoliation caused by the disease impacts root size, sugar quality, leaf regrowth, and impurity concentrations. Management strategies including boron-containing compounds have shown fungistatic properties potentially reducing field disease severity. Field studies were established to investigate the effects of foliar applied boron (B) on sugarbeet growth and CLS severity. Treatments included a standard fungicide program, three foliar B treatments (0.11, 0.28, or 0.56 kg sodium tetraborate ha-1 (0.1, 0.25, or 0.5 lb A-1)) applied at 10 to 14 day intervals individually, the same three foliar B treatments applied in conjunction with a standard fungicide program, and a non-treated check for comparison. Foliar B did not reduce CLS in field environments across site years. In vitro analysis of C. beticola response to B demonstrated lower EC50 values with sodium tetraborate than boric acid. However, both sodium tetraborate and boric acid increased EC50 values compared to the thiophanate-methyl control. Reduced control options combined with increased CLS resistance will require further evaluation of alternative control measures possibly including various B timings and increased B concentrations.
Introgression of the Cercospora Leaf Spot (CLS) Disease Resistance Trait From KEMS06 Sugar Beet Germplasm Into Two Double-Haploid Breeding Lines, KDH4-9 and KDH13
Abstract View Article
Cercospora leaf spot (CLS), caused by the fungal pathogen Cercospora beticola, is considered one of the most destructive foliar diseases of sugar beet (Beta vulgaris). CLS causes leaf damage often followed by intensive foliage regrowth which can result in considerable sugar losses unless timely applications of fungicides are applied throughout the growing season. While progress is being made towards improving CLS resistance in commercially available varieties of sugar beet, disease-prone areas still require multiple applications of fungicides during the growing season to keep sugar beet crop losses to a minimum. Recently, the sugar beet germplasm KEMS06 (PI 683514) derived from an ethyl methanesulfonate (EMS)-mutagenized population was found to have high CLS resistance. Sibling cohorts of KEMS06 have shown diverse and tractable phenotypes suggesting that the CLS resistance trait from KEMS06 may contain genetic underpinnings that have not been leveraged before in commercially available sugar beet varieties. In this report, we describe the use of greenhouse CLS assays to characterize the CLS resistance trait from the KEMS06 sugar beet germplasm. Two different hybrid (resistant x susceptible) crosses were generated, and the disease resistance segregation patterns with corresponding variance scores in the successive filial generations were measured. The results presented in this report strongly suggest the CLS resistance trait in KEMS06 is directly linked to underlying genetic determinants that are segregating in-step across the population in a quantitative manner. Heritability of the KEMS06 CLS resistance trait was tractable into the F2, F3, and F4 filial generations. By following a single plant descent methodology—expedited by the use of self-fertility traits in the parental lines—complete introgression of the KEMS06 CLS resistance trait was observed in progeny families. In addition, the greenhouse methods described within this report accelerated our CLS resistance trait discovery and development pre-breeding timeline by reducing the time that would normally be required to introgress and fix disease resistance traits into new sugar beet germplasm by one to
Microbial Isolates From North American Sugar Beet Factory Juices and Biofilms
Abstract View Article
During sugar beet processing, microbes from infected roots, storage piles, and soils carry over throughout sugar extraction, creating operational challenges and resulting in sucrose losses. In this study, diffusion tower juice and biofilm samples were obtained from 18 North American sugar beet factories for microbial sampling to characterize issues relating to raw sugar manufacturing, such as increased sample viscosity from bacterial exopolysaccharides (EPS) production. A broad sampling strategy was applied to obtain diverse microbial isolates for experimental characterization. In total, 379 isolates, belonging to 22 genera, were obtained from 33 diffuser tower juice samples, and 233 isolates, belonging to 26 genera, were obtained from 21 biofilm samples. A subset of 54 strains representing the most common genera (Leuconostoc, Peribacillus, Bacillus, Pantoea, Rahnella, Acinetobacter, and Weissella) were grown in high sucrose-containing medium. Among these, 10 strains were identified as capable of greatly increasing viscosity in the flask cultures, likely due to EPS production.