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The development of wheat (Triticum aestivum L.) cultivars resistant to Fusarium head blight (FHB) (caused by Fusarium graminearum Schwabe) requires screening methodologies that accurately characterize reaction to this disease. The objectives of this study were (i) to characterize the stability of cultivars for their FHB reaction and (ii) to define an optimum resource allocation for FHB evaluation. Fourteen cultivars were evaluated in FHB-screening nurseries at two locations across a 4-yr period. Field data were used to calculate disease incidence (INC) as the frequency of symptomatic spikes and disease index (DIS) as the mean disease score of all spikes. FHB reaction also was evaluated on harvested grain as percent visually scabby kernels (VSK) and deoxynivalenol (DON) concentration. Significant differences among cultivars for all FHB parameters were found in each environment. Pearson correlation coefficients among FHB parameters were positive and highly significant, ranging from 0.32 between INC and DON to 0.72 between INC and DIS. Spearman rank correlation coefficients for yearly cultivar rankings and Kendall's coefficient of concordance were high, indicating similarity of the rankings of the tested cultivars in different environments. Visually scabby kernels was the FHB parameter with highest similarity for cultivar ranking across environments. Most of the cultivars, including susceptible ones, expressed stability for FHB reaction. Optimum resource allocation for DIS was most affected by the number of environments with three being the minimum to accurately characterize a genotype's resistance level. Using more than three replications or scoring more than 10 spikes per plot had little practical value in characterizing FHB reaction., FUSARIUM HEAD BLIGHT, caused primarily by Fusarium graminearum, is an important disease throughout major spring wheat-production regions of the USA, Canada, and other parts of the world. Even low disease [...]

Fusarium head blight (FHB) is a disease problem (primarily caused by Fusarium graminearum Schwabe) that affects the quality and yield of barley (Hordeum vulgare L.) grain. The objectives of this study were to identify the location of quantitative trait loci (QTL) for resistance to FHB in a two-rowed by six-rowed population, to examine the association of FHB resistance with heading date and the Vrs1 (two-rowed spike morphology) locus, to validate the location of the major FHB resistance QTL primarily detected in the field, and to identify simple sequence repeat (SSR) markers linked to the QTL for FHB resistance. We created a genetic map of 143 molcular markers from a population derived from the parents Fredrickson (two-rowed, moderately resistant) and Stander (six-rowed, susceptible). The Fredrickson/Stander population was evaluated in two field environments by a grain spawn inoculation method, two field environments by a spray inoculation, and two greenhouse environments. QTL analysis detected three distinct regions on chromosome 2(2H) associated with FHB resistance; two of these regions were also associated with resistance to deoxynivalenol (DON) accumulation. One FHB resistance QTL was also associated with heading date, while another FHB resistance QTL was found associated with the Vrs1 locus. The third FHB resistance QTL was detected only in the greenhouse, but was coincident with a QTL for resistance to DON accumulation in the field. All three QTL were detected in the greenhouse, indicating that this environment may be useful for selecting FHB resistant barley genotypes. SSR markers were identified that are linked with each QTL and could prove useful for marker-assisted trait manipulation. Finally, the two major QTL detected in the field were validated using an independent population with Fredrickson and Stander parents., FUSARIUM HEAD BLIGHT has become a significant disease problem in barley in several regions around the world. In 1993, FHB reemerged in the northern Great Plains causing about $406 million [...]

`McVey' is a hard red spring wheat (Triticum aestivum L.) (Reg. no. CV-894, PI 612966) cooperatively developed and released by the Minnesota Agricultural Experiment Station and USDA-ARS in February 1999. [...]

`HJ98' is a hard red spring wheat (Triticum aestivum L.) (Reg. no. CV-872, PI 608723) cooperatively developed and released by the Minnesota Agricultural Experiment Station and USDA-ARS in February 1998. [...]

'Ulen' is a hard red spring wheat (Triticum aestivum L.) (Reg. no. CV-984, PI 639921) cultivar developed and released by the Minnesota Agricultural Experiment Station in cooperation with USDA-ARS in [...]

'Oklee' is a hard red spring wheat (Triticum aestivum L.) (Reg. no. CV-963, PI 634553) developed and released by the Minnesota Agricultural Experiment Station in cooperation with USDA-ARS in January [...]

`Lacey' a six-rowed spring barley (Hordeum vulgare L.) (Reg. no. CV-290, PI 613603), was developed by the Minnesota Agricultural Experiment Station and released in February 2000. It was developed in [...]

`MNBrite' (Reg. no. CV-275, PI 603050) is a spring barley (Hordeum vulgate L.) developed by the Minnesota Agricultural Experiment Station and released in February 1998. MNBrite was developed in a [...]