The aim of this study was to identify QTLs associated with the maintenance of
grain quality following post-anthesis heat stress. A population of 64 F6Halberd X Cutter
recombinant inbred lines (RILs) was exposed to either heat stress or control conditions in
the greenhouse, starting ten days after anthesis. Grain quality was determined using the
sodium dodecyl sulfate (SDS) sedimentation test, a significant predictor of bread baking
quality. The percent change in SDS sedimentation test scores between the heat and control
populations was used to identify QTLs associated with quality stability. Four QTLs were
identified, located one each on chromosomes 1B, 1D, 4A, and 7A. Three of the QTLs,
those on 1B, 1D, and 4A, were associated with variations in SDS sedimentation level. The
QTL on chromosome 7A was associated with the percent change in SDS sedimentation
scores between heat-stressed and control conditions. This indicated a relationship between
the identified QTL and quality stability. To confirm the detected QTLs, eighty advanced
lines grown at three Texas nurseries were genotyped and tested for relationships between
QTL-associated markers, quality traits, and stability of the quality traits. Quality trait
stability was estimated using the coefficient of variability (CV%) of quality traits between growing sites. Quality characters analyzed in the advanced lines included kernel hardness,
mixograph peak time, kernel weight, flour yield, SDS sedimentation, and grain yield.
The analysis showed support for the effect of the QTLs on chromosomes 1B, 1D, and
4A. Further analysis will be needed to confirm the QTL on 7A, in particular. The mapping of
additional markers will be necessary. However, the potential importance of this QTL and the
abundance of other QTLs detected in this region make it worth investigating.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-08-7156 |
| Date | 2009 August 1900 |
| Creators | Beecher, Francis Ward |
| Contributors | Hays, Dirk, Ibrahim, Amir |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | application/pdf |
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