2002 Uniform Regional Scab Nursery for Spring Wheat Parents

 

 

 

Coordinator:  David F. Garvin

USDA-ARS, Plant Science Research Unit

411 Borlaug Hall, University of Minnesota

1991 Upper Buford Circle, St. Paul, MN 55108

Report prepared by: David F. Garvin and Leanne Matthiesen

 

 

The Uniform Regional Scab Nursery was grown for the eighth year in 2002.  Six locations were included in the nursery, including 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) represent possible new sources of scab resistance and 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, 4 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 in the individual location tables.  A final table reporting overall entry means for parameters across locations is included after individual location data tables.  Further, relative rankings of entries for disease incidence, disease severity, disease index, VSK and DON are provided as new tables 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.  It should be noted that the nursery locations in Minnesota do not record VSK ratings if they exceed 50%, and thus the VSK means at these locations will be biased towards values lower than the true means.  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).

 

 

 

Cooperators for 2002 Uniform Regional Scab Nursery for Spring Wheat Parents

 

Richard Frohberg, John Lukach, Mohamed Mergoum and Robert Stack

North Dakota State University

 

Yue Jin and Karl Glover

South Dakota State University

 

Jim Anderson, Ruth Dill-Macky and John Wiersma

University of Minnesota

 

Jeannie Gilbert and Gavin Humphreys

Agri-Food Canada, Winnipeg, Manitoba