Chevron and Chevron progeny have been used extensively in breeding for resistance to Fusarium Head Blight (FHB) and Kernel Discoloration (KD) in the Midwest U.S. barley breeding programs. Fortunately, resistant Chevron progeny often have a correlated advantage i.e., resistance to KD. Unfortunately, resistant Chevron progeny are often high in grain protein. The association between resistance to FHB and KD with high GP has serious consequences when malting quality is the breeding goal.To develop strategies to introgress genes for resistance to FHB, we are studying the genetics of FHB, KD and Grain Protein (GP) in three populations involving Chevron progeny. These populations were evaluated at three locations in 1998 and 1999. The correlation between FHB/ KD for the three populations were 0.4, 0.4 and 0.6 based on the mean of the environments. On the other hand, both FHB and KD were negatively associated with GP. The FHB/GP correlations for the three populations were –0.3, -0.2 and –0.3. Similarly, the KD/GP correlations were –0.4, -0.2 and –0.4. While theses correlations are not high, the most resistant lines to FHB and KD in each of the three populations had 1-2% higher grain protein than the quality check. The genetic basis for the association between FHB, KD and GP can be partially explained by molecular mapping data.

Working with the Chevron/M69 population de la Pena et al. (Theor Appl Genet, 99, in press) identified several genomic regions associated with resistance to FHB and KD. Four of the regions associated with FHB in chromosome 1, 2 and 4 were also associated with KD. We mapped grain protein QTLs in the Chevron/M69 and identified two QTLs associated with GP located in chromosome 6. The GP QTLs on chromosome 6 mapped at the same location as two major KD QTLs identified previously and in both cases the Chevron allele was associated with resistance to KD and high GP. We failure to detect QTLs associated with both FHB and GP. We are currently mapping the three traits using three populations involving Chevron derived parents and we will present some results of this study.