The aims of this study were to evaluate the functionality and the practicality
of hydroponics in the process of wheat breeding compared to a conventional
glasshouse cultivation method. Furthermore for assessing the screening
capability of drought tolerance in wheat cultivars using a hydroponic system
was used and morphological yield components were measured and protein
concentration fluctuations by means of SE-HPLC were analyzed.
x In the first study, five South African wheat cultivars, SST 88, Baviaans,
Steenbras, SST 876 and Kariega, were planted into two identical hydroponic
systems. A second set of the five cultivars where planted two months after
the first planting to separate the two stress periods, the first being drought
stress before seed fill and in the second planting, stress was induced at
seedling stage. This was done simultaneously.
x When maturity was reached, several yield component measurements were
taken.
x The influences of the drought treatment on the different yield components
were established.
x Protein extracts of wheat flour were analyzed by SE-HPLC.
x SDS was used for the first protein extraction step, and the rest of the
proteins were extracted by sonication.
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x The SE-HPLC method fractionated the storage proteins (both SDS-soluble
and SDS-insoluble) into four distinct peaks of decreasing molecular size
range, representing mainly larger polymeric proteins (mainly HMWglutenins),
smaller polymeric proteins (mainly LMW-glutenins), larger
monomeric proteins (mainly gliadins), and smaller monomeric proteins
(mainly albumins and globulins).
x Relationships between the amount and size-distribution of polymeric and
monomeric proteins and flour quality properties were established.
x The influence of the drought treatment on protein fractions and quality
characteristics was also determined by SE-HPLC.
x The results showed that both the genotype and drought conditions had a
significant influence on the yield components and protein characteristics.
x The use of a hydroponic cultivation method for the induction of drought
conditions at any stage of development of wheat can be done at a highly
significant level, not only for inducing stresses but for re-establishing and
maintaining optimum conditions as well.
x SE-HPLC provided a simple and an objective test for measuring the relative
size-distributions of wheat storage proteins.
x In the second study two South African wheat cultivars, Baviaans and
Steenbras, were planted into two identical hydroponic systems (differing
only in the makeup of the nutrient solution) and in pots.
x Emergence percentages and dates were recorded for a one month period
after the emergence of the first seedling in the experiment.
x When maturity was reached several yield component measurements were
taken.
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x The two hydroponic systems provided a better emergence environment
compared to the potting solution, indicating that there is already a higher
potential number of crosses that can be made in the breeding program using
a hydroponic cultivation method.
x The effect of treatment was highly significant for most of the yield
characteristics, indicating that the effectiveness of the treatments played a
significant role in the yield potential of each cultivar.
x Findings indicated that by using a hydroponic cultivation method instead of
the potting method for growing wheat, parent lines can increase the amount
of crosses that can potentially be made, thus increasing the amount, potential
success and quality of the crosses made, together with the potential of
producing seeds that will have the potential of a higher emergence rate.
x The hydroponic cultivation method using the chemicult solution proved to be the most effective method of cultivation during this study.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-02142006-081835 |
| Date | 14 February 2006 |
| Creators | du Toit, Andreas Gerhardus Adriaan |
| Contributors | Prof MT Labuschagne |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-02142006-081835/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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