Browsing by Author "Cowger, Christina"
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- Evaluation of Methods for Measuring Fusarium-Damaged Kernels of WheatAckerman, Arlyn J.; Holmes, Ryan; Gaskins, Ezekiel; Jordan, Kathleen E.; Hicks, Dawn S.; Fitzgerald, Joshua; Griffey, Carl A.; Mason, Richard Esten; Harrison, Stephen A.; Murphy, Joseph Paul; Cowger, Christina; Boyles, Richard E. (MDPI, 2022-02-21)Fusarium head blight (FHB) is one of the most economically destructive diseases of wheat (Triticum aestivum L.), causing substantial yield and quality loss worldwide. Fusarium graminearum is the predominant causal pathogen of FHB in the U.S., and produces deoxynivalenol (DON), a mycotoxin that accumulates in the grain throughout infection. FHB results in kernel damage, a visual symptom that is quantified by a human observer enumerating or estimating the percentage of Fusarium-damaged kernels (FDK) in a sample of grain. To date, FDK estimation is the most efficient and accurate method of predicting DON content without measuring presence in a laboratory. For this experiment, 1266 entries collectively representing elite varieties and SunGrains advanced breeding lines encompassing four inoculated FHB nurseries were represented in the analysis. All plots were subjected to a manual FDK count, both exact and estimated, near-infrared spectroscopy (NIR) analysis, DON laboratory analysis, and digital imaging seed phenotyping using the Vibe QM3 instrument developed by Vibe imaging analytics. Among the FDK analytical platforms used to establish percentage FDK within grain samples, Vibe QM3 showed the strongest prediction capabilities of DON content in experimental samples, R2 = 0.63, and higher yet when deployed as FDK GEBVs, R2 = 0.76. Additionally, Vibe QM3 was shown to detect a significant SNP association at locus S3B_9439629 within major FHB resistance quantitative trait locus (QTL) Fhb1. Visual estimates of FDK showed higher prediction capabilities of DON content in grain subsamples than previously expected when deployed as genomic estimated breeding values (GEBVs) (R2 = 0.71), and the highest accuracy in genomic prediction, followed by Vibe QM3 digital imaging, with average Pearson’s correlations of r = 0.594 and r = 0.588 between observed and predicted values, respectively. These results demonstrate that seed phenotyping using traditional or automated platforms to determine FDK boast various throughput and efficacy that must be weighed appropriately when determining application in breeding programs to screen for and develop resistance to FHB and DON accumulation in wheat germplasms.
- Managing Fusarium Head Blight in Winter Barley With Cultivar Resistance and FungicideCowger, Christina; Arellano, Consuelo; Marshall, David; Fitzgerald, Joshua (2019-08)Although there has been research on managing Fusarium head blight (FHB) in spring barley, little has been published on cultivar resistance and optimal fungicide timing for FHB management in winter barley. A 3-year (2015 to 2017) field experiment was conducted to measure FHB resistance of winter barley varieties, gauge the potential benefit from a fungicide, and help determine the optimal timing for fungicide application. The split-plot experiment took place in a misted, inoculated nursery in Raleigh, North Carolina using main plots of four winter barley cultivars (Atlantic, Endeavor, Nomini, and Thoroughbred). Three fungicide treatments were applied to subplots: prothioconazole + tebuconazole at full spike emergence, the same fungicide 6 days later, or no fungicide. The late applications significantly reduced FHB index in each of 3 years and significantly reduced deoxynivalenol (DON) in harvested grain in 2 of the 3 years. Applications at full spike emergence also yielded significant benefit in 1 of the 3 years for each parameter. Neither disease symptoms nor DON gave reason to prefer one of the fungicide timings over the other. Across the 3 years, DON ranked the cultivars Endeavor < Nomini = Thoroughbred < Atlantic. Combining the moderate resistance of Endeavor with a fungicide application and averaging the two timings resulted in a 75% DON reduction compared with unsprayed Atlantic. Taken together, our results indicate that barley growers concerned about minimizing DON should both plant moderately resistant varieties and apply fungicide if there is scab risk. During the same period, 16 commercial winter barley cultivars were tested in from three to seven Virginia and North Carolina environments each, and the DON results were compared after standardization across environments. The winter two-row malting barley cultivars Endeavor and Calypso displayed superior and robust DON resistance across environments.
- Registration of 'Hilliard' wheatGriffey, Carl A.; Malla, Subas; Brooks, Wynse S.; Seago, John E.; Christopher, Anthony; Thomason, Wade E.; Pitman, Robert M.; Markham, Robin; Vaughn, Mark E.; Dunaway, David W.; Beahm, Mary; Barrack, C. Lin; Rucker, Elizabeth; Behl, Harry D.; Hardiman, Thomas H.; Beahm, Bruce R.; Browning, Phillip; Schmale, David G. III; McMaster, Nicole J.; Custis, J. Tommy; Gulick, Steve; Ashburn, S. Bobby; Jones, Ned, Jr.; Baik, Byung-Kee; Bockelman, Harold; Marshall, David; Fountain, Myron O.; Brown-Guedira, Gina L.; Cowger, Christina; Cambron, Sue; Kolmer, James; Jin, Yue; Chen, Xianming; Garland-Campbell, Kimberly; Sparry, Ellen (2020-09)'Hilliard' (Reg. no. CV-1163, PI 676271), a soft red winter (SRW) wheat (Triticum aestivum L.) developed and tested as VA11W-108 by the Virginia Agricultural Experiment Station, was released in March 2015. Hilliard was derived from the cross '25R47'/'Jamestown'. Hilliard is widely adapted, from Texas to Ontario, Canada, and provides producers with a mid-season, medium height, awned, semi-dwarf (Rht2) cul tivar that has very high yield potential, good straw strength, and intermediate grain volume weight and quality. It expresses moderate to high levels of resistance to most diseases prevalent in the eastern United States and Ontario. In the 2016-2018 USDA-ARS Uniform SRW Wheat nurseries, Hilliard ranked first in grain yield in the southern nursery across all 3 yr (5,147-5,758 kg ha(-1)). In the uniform eastern nursery, it ranked first for grain yield in 2016 (6,159 kg ha(-1)) and 2017 (5,633 kg ha(-1)) and second in 2018 (5,515 kg ha(-1)). Grain volume weights of Hilliard were similar to overall trial averages in the uniform southern (73.4-75.2 kg hl(-1)) and eastern (70-75.8 kg hl(-1)) nurseries. Hilliard has soft grain texture with flour softness equivalent values varying from 58.1 to 61.7 g 100 g(-1). Straight grade flour yields on a Quadrumat Senior mill varied from 66.8 to 68.4 g kg(-1). Flour protein concentration varied from 7.0 to 9.1 g 100 g(-1) and gluten strength from 108 to 128 g 100 g(-1), as measured by lactic acid solvent retention capacity. Cookie spread diameter varied from 18.3 to 18.6 cm.