Annual Progress Report on Malting Barley Research March, 2007

The MSU barley improvement program remains a consistent contributor to the AMBA
Pilot Scale Evaluation Program. We select our best-performing lines that malt well in the
Madison Micromalt Evaluation Program and advance these to pilot scale evaluation. In
2007, we have two lines that passed first year evaluation, MT010158 and MT010160, and
have added three new lines, MT020155, MT020205 and MT030042 (Table 3).
Other Barley Research and Future Direction of Program
We extensively and effectively utilize molecular markers. While perhaps not speeding
the process of line development, they provide a level of certainty in selection. The ‘Karl’
low grain protein allele provides a perfect example. We initially mapped the gene (See et
al., 2002), and since then fine-mapped the gene with markers derived from an analogous
system found in wheat (Uauy et al., 2006). While tracking the genetics underlying this
trait, we identified lines that carry a double recombination event surrounding the Karl
allele, making it possible to backcross this gene into well-adapted, high quality lines
without dragging a large part of Karl’s chromosome 6 along. In a 2-replication yield trial
we grew last season, utilizing BC4 derivatives (the Lewis allele backcrossed into Karl,
and the Karl allele backcrossed into Lewis), we found that the Karl allele had a profound
impact on Lewis yield and quality (see Table 4). Yield and starch percentage were
improved, and grain protein percentage was reduced.
In wheat, this appears to be the result of a defect in a transcription factor (Uauy et al.,
2006), while in barley the molecular basis for this effect remains unclear. The
phenotypic effect of the allelic difference seems to be to increase the duration of grainfill
in the low grain protein lines. If there are no negative pleiotropic effects on malting
quality, this should enable the development of low protein percent, high starch percent
barley lines with increased yield potential.
Table 3. 2006 Replicated qGPC6H Yield Trial
Karl, Karl High Grain Protein BC4 lines; Lewis, Lewis Low Grain Protein BC4 lines
When superscripts are different, means differ at p