Annual Progress Report on Malting Barley Research March, 2002

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3. Mapping New Sources of Resistance to Fusarium Head Blight. The mapping
populations Atahualpa x M81 and Hor211 x Lacey have been set up to identify new QTL
for FHB resistance. In breeding populations, we have identified resistant progeny from
crosses to both of these sources giving us confidence that genetic investigation will reveal
novel genes for disease resistance. Research sponsored through the U.S.Wheat and
Barley Scab Initiative has shown that Atahualpa and Hor211 are genetically different
from other sources of FHB resistance. This research has also demonstrated that
previously identified genetic markers, linked to established FHB resistance QTL, do not
account for much or any of the variation for resistance in these sources of resistance.
Therefore further research with these new sources of resistance will likely lead to novel
genes and DNA markers that should be useful marker assisted breeding efforts to develop
new disease resistant barley varieties.
4. Near Isogenic Lines and for FHB QTL. Post Doc Lex Nduulu continues to develop
near isogenic lines (NIL) for FHB QTL regions identified in the Chevron x M69
population (de le Pena et al, 1999) on chromosome 2 and 6 and the Frederickson x
Stander population (Mesfin et al, in preperation) for chromosome 2. We have completed
4 and 2 backcrosses utilizing marker assisted selection (MAS) for the Chevron and
Frederickson derived lines, respectively. We will also be using these NIL to generate
fine maps in these regions to more precisely define the location of the QTLs.
5. Marker Assisted Selection (MAS) in Lacey background. To better utilize Chevron
FHB resistance alleles at FHB QTL on chromosomes 2 and 6 we have evaluated MAS
for these regions in crosses with our newest variety Lacey. Simple sequence repeat
(SSR) markers were used to conduct selection on individual F2 plants in the summer of
2000. These lines have been advanced by single seed decent and F4:5 lines were
evaluated in 2001. MAS for the Chevron allele on chromosome two resulted in a 43%
reduction in FHB severity compared to the random control. MAS for the Chevron allele
on chromosome six resulted in a 11% reduction in FHB severity.
6. Mapping Disease Resistance in Hordeum vulgares subsp. Spontaneum. Post Doc
Laszlo Gyenis continues to develop a map and collect disease data in a cross between a
spontaneum accession (OUH602) and Harrington. The wild parent has disease resistance
to four diseases; spot blotch, net blotch, scald, and septoria. This work is being done in
collaboration with Gary Muehlbauer and Brian Steffenson.
Publications
Rasmusson, D. C., K. P. Smith, R. Dill-Macky, E. L. Schiefelbein, and J. V. Wiersma .
2001. Registration of 'Lacey Barley'. Crop Sci 41: 1991.
Kolb, F.L., G-H. Bai, G.J. Muehlbauer, J.A. Anderson, K.P. Smith, and G. Fedak. 2001.
Host Plant Resistance Genes for Fusarium Head Blight: Mapping and Manipulation with
Molecular Markers. Crop Sci 41: 611-619.
Simon, H. M., Smith, K. P., Dodsworth, J. A., Guenthner, B., Handelsman, J. and
Goodman, R. M. 2001. Influence of Tomato Genotype on Growth of Inoculated and
Indigenous Bacteria in the Spermosphere. Appl. Environ. Microbiol. 67:514-52