Quality prediction and improvement in Lesotho commercial wheat (Triticum aestivum L.) cultivars
Doctoral Thesis UFS multilingual coverage
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Abstract
English
• The objectives of this study were to characterize wheat cultivars grown in Lesotho according to
their glutenin and gliadin banding patterns with the use of SOS-PAGE, estimate GCA, SCA,
h2, heterosis and correlation of wheat quality traits by crossing poor, medium and good
breadmaking qualities in a full diallel design to create F 1 and F2 progeny, and determine the
potential of SE-HPLC in predicting quality of wheat cultivars.
• Glutenin and gliadin proteins were separated using SOS-PAGE. Cultivars used for estimating
combining ability were grown in pots and crossed in the greenhouse at Bloemfontein. The F 1
progeny were grown in Lesotho and Bloemfontein while the F2 progeny were grown in
Bloemfontein. Protein extracted from the wheat flour of all this material were analysed by SEHPLC.
• Seven wheat quality characteristics were analysed at the Agricultural Research Council,
Bethlehem for parents, F1 and F2 progeny.
• Analysis of variance and correlations were employed as statistical tools to analyse the data
generated from storage protein, combining ability trials and SE-HPLC.
• Results revealed that gliadins and LMW-GS were able to distinguish 30 cultivars of wheat
grown in Lesotho, while HMW-GS enabled cultivars to be grouped.
• The ANO VA indcated significant differences between parents and F 1 progeny and parents and
F 2 progeny for all characteristics studied. The mean squares for GCA, SCA and reciprocals
were significant for all measured characteristics in the F 1 generation, while in the F 2, the mean
squares for GCA were significant for all but one characterisics. Mean squares for SCA and
reciprocals were significant for all characteristics in the F2 generation.
• To improve or enhance quality, Wanda, SST 124 and Sceptre could be incorporated into the
breeding programme. Crosses such as Sceptre x Kariega, SST 124 x Nata, Wanda x Nata,
Sceptre x Wanda, Kariega x Wanda, Kariega x Sceptre, SST 124 x Sceptre, Wanda x SST 124,
Nata x Kariega and Nata x SST 124 should also be incorporated into the programme.
• F 1 progeny showed non-additive gene action in all characteristics while F2 progeny showed
four characteristics to be controlled by non-additive gene action while the others were
controlled by additive gene action.
• Heritability in the broad sense was high for all characteristics in the F 1 and F2 progeny, whereas
heritability in the narrow sense was higher for F2thanF1 progeny.
• Midparent heterosis and best parent heterosis was expressed in four characteristics.
• Highly significantly positive and negative correlations were observed between quality
characteristics in F1 and F2 progeny.
• Results ofSE-HPLC showed that large polymeric and large monomeric proteins can be used as
predictors of good and poor quality respectively, in the parents and F 1 and F2 progeny.
Keywords
English
Wheat -- Genetic aspects Wheat -- Breeding -- Lesotho Wheat -- Quality