Submitted to: Uniform Regional Scab Nursery for Spring Wheat Parents
Publication Type: Other
Publication Acceptance Date: 3/1/2003
Publication Date: 3/1/2003
Citation: Garvin, D.F., Mattiesen, L. 2003. Report of the 2002 Uniform Regional Scab Nursery for Spring Wheat Parents. 15 p. Available: http://www.wheat.pw.usda.gov. Interpretive Summary:
Technical Abstract: The Uniform Regional Scab Nursery was grown for the eighth year in 2002. Six locations were included in the nursery: Brookings, SD; St. Paul and Crookston, MN; Prosper and Langdon, ND; and Glenlea, MB, Canada. Data were obtained from all locations for inclusion in this report. A total of 44 entries were included in the nursery in 2002. This included the resistant checks 2375, BacUp, and ND2710, and the susceptible checks Wheaton and Oslo. The other 39 entries were contributed by the University of Minnesota, North Dakota State University, South Dakota State University, Agriculture and Agri-Food Canada, Western Plant Breeders, and Agripro. Seven of these 39 entries were durums. Five genotypes from South Dakota (PI entries) representing possible new sources of scab resistance were included in the nursery. The field data collected at each location varied, but a core set of traits evaluated on entries at 5 locations or more included incidence of scab (expressed as % infected heads), disease severity (expressed as % of diseased florets on infected heads), disease index (incidence x severity/100), and visual scabby kernel ratings (VSK, tombstone), expressed as % kernels in a grain sample. Additionally, four locations provided grain deoxynivalenol (DON) concentrations, expressed as ppm in a grain sample. Other trait data were gathered at the different locations and are presented as well. Relative rankings of entries for disease incidence, disease severity, disease index, VSK, and DON are provided in this year's report. Disease pressure varied from location to location, with mean disease incidence ranging from a low of 52.3% for Langdon to a high of 99.8% at Brookings. Mean location severities ranged from 7.7% at Langdon to 67.4% at Prosper, while mean disease index ranged from 4.8% at Langdon to 46.9% at Brookings. Mean VSK ranged from 8% at Crookston to 46.5% at Prosper. Mean location DON concentrations ranged from 3.5 ppm at Crookston to 36.9 ppm at Prosper. Correlation coefficients were calculated between disease index, VSK, and DON, using overall means calculated from the locations at which each of these parameters was measured. The correlations among these parameters were in each instance positive and significant. The correlation between disease index and VSK (4 locations) was 0.91, while disease index and DON (3 locations) exhibited a correlation of 0.85. Lastly, VSK and DON (3 locations) also exhibited a significant correlation (0.77).