Other mutant alleles of lys5 (see
Patron et al., 2002) might offer more favourable combinations of
grain weight and b-glucan content. Although further breeding to
enhance grain weight in isa1 mutant lines is likely to result in higher
starch to phytoglycogen ratios, the presence of some phytoglycogen
may have advantages for alcohol production and for some food
applications. As reported previously, the sex6 mutation strongly
affects starch properties, resulting in a resistant starch with potential
health benefits. However, grain weight and starch contents
of lines carrying the sex6 mutation are likely to be intrinsically low.
The valuable starch properties of lines carrying the wax mutation
are modified by genetic background. It seems likely that further
breeding could enhance freeze-thaw stability in particular