2000 Uniform Regional Scab Nursery for Spring Wheat Parents
 
 Robert Busch: Coordinator, USDA-ARS. Plant Science Unit, St. Paul, MN  55108 
 (Retired)
 The assistance of Gary Linkert and Leanne Matthiesen are gratefully 
 acknowledged.
 
 
 The Uniform Regional Scab Nursery was grown for the sixth time in 2000 
 at 7 locations including St. Paul and Crookston, MN; Langdon and Prosper, 
 ND; Brookings, SD;  Ames, IA; and  Glenlea, Manitoba.  All nurseries used 
 were misted and inoculated with Fusarium to obtain infection in the entries 
 except the nursery in  Ames, IA.  This nursery depended upon natural 
 rainfall and inoculum for infection.
 
 A total of 43 entries were tested including 5 checks ( three with  resistance  
 2375, BacUp, and ND2710, two susceptible Oslo and Wheaton) and 25 parental 
 spring wheat lines, 5 germplasm lines entered from South Dakotas Germplasm 
 Screening Nursery (designated with * in tables) and  including 8 durums.  Most 
 entries have a Chinese source of resistance in their pedigrees except for the 
 durums and germplasm lines.
 
 All entries were planted in single rows or hill-planted with 2 to 4 replicates 
 in each location.  Inoculation was conducted by scattering infected kernels and/or 
 by spraying the spikes with macroconidia spore suspension during anthesis (2 x104  
 to 10 x 104 spores/ml).  A misting system was used for enhancing the disease infection and 
 spread.
 
 Visual head symptoms of scab infection and post-harvested visual scabby kernel 
 rating (or % Tombstone) based on a standard set were assessed.  DON analyses 
 were also conducted at four locations.  Each location's data are presented separately and 
 entry means were used for the combined location's analysis. 
 
 Level of disease varied with locations.  Location means for Disease Index or FHB 
 index ranged from 1.8% at Langdon to 59% at Prosper, ND.  Percent tombstone 
 ranged from 11% at Langdon to 47% at Prosper. Entry performance varied with locations.  
 Heading date was not correlated with any scab resistance trait measure at the locations that 
 recorded heading. 
 
 Correlations among the trait means over locations are given in Table 10.  The 
 data indicated that DON, % Tombstone, Disease Index and Yield were highly correlated 
 with the lowest association between DON and Yield.   Severity and Incidence were also 
 highly correlated as well.  Selection for Disease Index , Tombstone, or DON appear to 
 be providing similar information for resistance in the scab nurseries in 2000.