| Wheat grain hardness among chromosome 5D homozygous recombinant substitution lines using different methods of measurement. Cereal Chemistry 76:249-254 |
Morris,C.F., DeMacon,V.L. and Giroux,M.J.
USDA-ARS Western Wheat Quality Lab and Washington State University |
| The level of grain hardness of wheat
(Triticum aestivum) cultivars profoundly affects milling properties and
end-use. We examined grain gardness among a genetically defined set of 83 chromosome
5D homozygous recominant substitution lines derived from soft whea cv. Chinese
Spring and hard wheat cv. Cheyenne and compared four common methods of measuring
wehat grain hardness. Measures of grain hardness included a modified particle
size index, Brabender Quadrumant flour milling, near-infrared reflectance (NIR)
spectroscopy, and the single-kernel characterization system (SKCS). Duncan's
multiple range test was used to group recombinant lines according to parental
classes. Quadrumat milling fractions, percent bran and middlings, were well
correlated to NIR and SKCS grain hardness, whereas break flour, a traditional
measure of grain hardness, was poorly correlated to other hardness measures.
NIR and SKCS grain hardness measures provided the greatest and similar mean
separations. Both methods identified recombinant lines as being significantly
outside either parental class and significantly different from and in between
the two parental classes. Between two divergent environments, correlations (r)
for Quadrumat bran and middlings percents and NIR and SKCS hardness ranged from
0.83 to 0.94. Analysis of variance indicated that lines differed substantially
for hardness, and hardness was highly influenced by environment, albeit consistently,
as indicated by low line-location model interaction terms. The results confirmed
the presence of major allelic differences assignable to chromosome 5D and suggested
the action of minor gene(s). Break flour, in particular, showed strong indications
of transgressive segregation independent of the Hardness (Ha) locus.
The Perten 4100 SKCS provided the best (most discriminating) measure of the
material properties of the wheat endosperm manifested by the action of the Ha
locus.
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