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dc.contributor.advisorLabuschagne, M. T.
dc.contributor.authorBarnard, Anri Danelle
dc.date.accessioned2018-05-17T07:28:43Z
dc.date.available2018-05-17T07:28:43Z
dc.date.issued1999
dc.identifier.urihttp://hdl.handle.net/11660/8281
dc.description.abstractEnglish: 1. The objective of this study was to select environmentally stable parental lines, and to determine the heritability of quality characteristics, the correlation between these characteristics, the combining ability of these quality characteristics, and the selection response. 2. A parental trial was planted at two diverse environments namely langgewens and Tygerhoek, to determine the influence of environment on the different quality traits and parents. locality had a significant influence on most of the characteristics (FPC, EX, FCL, MDT, FA, LFV, BSI,TKM and yield) whereas HlM, FSTand FOT were not influenced by the environment. 3. A correlation matrix performed on the collected data from the two localities showed that correlations tend to be environment specific. There were no consistent correlations between characteristics across envi ronments. 4. As expected, locality had a significant influence on most of the quality characteristics. Parents should be selected on average performance across localities. Kariega, SST 57 and Palmiet showed the least interaction with the environment and should therefore be considered as parents. Gamtoos was the best parent for FA and FST, but because of the 1B/1R translocation's negative effect on quality, this cultivar should be avoided as a parental line to improve quality. 5. At langgewens a diallel trial was conducted, on the parents and the F2 progeny, to determine the correlations, heritability, combining ability and selection response of the different quality characteristics. 6. Significant effects were found over the four replications for some of the quality characteristics. From this trial, Palmiet, Kariega, Nantes and SST57 were found to perform very well. Nantes and Kariega were involved in almost all the best performing F2 combinations and even though the progeny was F2, some heterosis was stiII evident. 7. Significant GCA was found for all the traits except FN, FCL and SDS. SCA was significant for FN, HLM and LFV, which could be an indication of heterotic effects in these traits. 8. To produce the best progeny, parental lines with the highest GCA for a specific trait should be used. High GCA effects is an indication of additive gene action, which again indicates high heritability. Kariega, Nantes, SST 57 and Palmiet proved to be the best cultivars to improve the different quality and yield characteristics. 9. The best specific combination to produce progeny with desirable milling characteristics was Nts/Kar, whereas Kar/Gmt proved to be the best specific combination to improve the rheological characteristics simultaneously. W92- 1/Nts can be used to develop desirable progenies for LFV. SST57/Kar proved to be the best combination to improve TKM. The SCA of W92-1 proved to be mostly influenced by the environment. 10. The GCA:SCA ratio was calculated to determine whether a character shows more additive or non-additive gene action. The following characteristics showed additive gene action: TKM, EX, BFY, FCL, HLM, GPC, LFV, MDT and FPC. The remainder of the characteristics showed very little variation between additive and non-additive gene action, except for FN, where the SCA was much higher. 11. To further confirm the above findings, the additive gene action was determined. Results were in agreement with previous findings, stating that TKM, EX and BFY was mainly under additive control, FCL, HLM, GPC, LFV, MDT and FPC showed mainly additive but also non-additive gene action and FN and SDS were under non-additive genetic control. 12. A phenotypic correlation matrix was performed to determine whether a positive or negative correlation exists between the quality and yield characteristics. Significant positive correlations were observed between HLM and TKM, EX and MDT, GPC and LFV and FPC, SDS and LFV, BFY and LFV, EX and MDT, FPC and LFV and FCL and MDT. This implies that selecting for one of these traits will simultaneously improve the other traits in a desirable environment. None of these correlations correlated with findings in the parental trial. Significant negative correlation existed between TKM and GPC and EX and FCL, implying a selection for one trait will influence the other trait negatively. 13. A genetic correlation matrix was also performed. Significant positive genetic correlations were observed between SDS and FN (0.858*), MDT and HLM (0.815*) and LFV and FPC (0.824*) indicating that an increase in one of these characteristics will result in an increase of the other character as well, irrespective of the environment. In the phenotypic correlation matrix these correlations were positive as well, but non-significant. 14. The broad and narrow sense heritability was calculated for the quality and yield characteristics. The narrow sense heritability varied from as high as 0.7089 for TKM to 0 for SDS and FN. These findings again indicate a good success in selecting for higher TKM. The broad sense heritabilities were relatively high for most of the characters, indicating a significant environmental influence in the non-additive or heterotic effects of these genes. 15.lndirect selection was calculated to find out whether it is possible to achieve more rapid progress through selection for a correlated response than from selection for the desired character itself. None of the indirect selections showed high response to selection for TKM and GPC, therefore to improve these characters, selection should be applied directly. Direct selection would be better to improve FCL, because of the negative correlations with the characteristics. None of the indirect selected characters could improve all the other characters simultaneously, but selection for HLM and MDT improved all the characteristics except FCL. Direct selection procedures should rather be used to improve specific quality characteristics. Indirect selection would be best to select for SDS and FN.en_ZA
dc.description.abstractAfrikaans: Die doel van hierdie studie was om ouerlyne te selekteer wat stabiel is oor omgewings, en om die oorerflikheid van kwaliteitseienskappe, die korrelasies tussen hierdie eienskappe, die kombineervermoë van hierdie eienskappe en die indirekte responsie op seleksie te bepaal. 2. 'n Ouerproef is op twee diverse lokaliteite naamlik Langgewens en Tygerhoek geplant, om die invloed van die omgewing op die kwaliteitseienskappe te bepaal. Omgewing het 'n betekenisvolle invloed op die meeste van die eienskappe gehad (FPC, EX, MDT, FA, LFV, BSI, TKM en opbrengs). HLM, FST en FDT is nie deur die omgewing beïnvloed nie. 3. In Korrelasiematriks is uitgevoer op die versamelde data van die twee lokaliteite. Die resultate toon dat korrelasies omgewing-spesifiek is. Daar was geen konstante korrelasies tussen eienskappe oor omgewings nie. 4. Soos verwag het die omgewing 'n groot invloed op die meeste kwaliteitseienskappe gehad. Ouers moet geselekteer word op grond van die gemiddelde data oor omgewings. Kariega, SST 57 en Palmiet het die minste interaksies met die omgewing getoon, en moet daarom as'ouers oorweeg word. Gamtoos was die beste ouer vir FA en FST, maar as gevolg van die negatiewe effek wat die 1B/1R translokasie op kwaliteit het, moet hierdie cultivar eerder as ouer vermy word in kruisings om kwaliteit te verbeter. 5. Op Langgewens is 'n dialeel analise uitgevoer op die ouer en F2 nageslag om die korrelasies, oorerflikhede, kombineervermoë en indirekte respons op seleksie van die verskillende kwaliteitseienskappe te bepaal. 6. Vir sommige kwaliteitseienskappe is betekenisvolle verskille oor die vier replikasies verkry. Vanuit hierdie proef is gevind dat Palmiet, Kariega, Nantes en SST57 die beste gevaar het. Nantes en Kariega was 'n ouer in byna al die beste F2 kombinasies, en selfs al was die nageslag F2's, was heterose steeds sigbaar. 7. Betekenisvolle GCA is gevind vir al die kenmerke, behalwe FN, FCL en SDS. SCA was betekenisvol vir FN, HLM en LFV, wat kan dui op heterose in hierdie eienskappe. 8. Om die beste nageslag te verseker, moet die ouers met die beste GCA vir 'n spesifieke eienskap gebruik word. Hoë GCA is 'n aanduiding van aditiewe geenwerking, wat verder op hoë oorerflikheid dui. Kariega, Nantes, SST 57 en Palmiet is die beste cultivars om die verskillende kwaliteit- en opbrengseienskappe te verbeter. 9. Die beste spesifieke kombinasie om nageslag met die verlangde maaleienskappe te verkry is Nts/Kar. Kar/Gmt is die beste spesifieke kombinasie om die reologiese eienskappe gelyktydig te verbeter. W92-1/Nts kan gebruik word om verlangde nageslag vir LFV te verkry, terwyl SST57/Kar die beste kombinasie is om TKM te verbeter. Die SCA van W92-1 word die meeste deur die omgewing beïnvloed. aditiewe genewerking toon. Die volgende eienskappe het additiewe 10. Die GCA:SCA ratio is bereken om vas te stelof 'n karakter meer aditiewe of niegenewerking getoon: TKM, EX, FCL, HLM, GPC, LFV, MDT en FPC. Die oorblywende eienskappe het min variasie tussen additiewe en nie-additiewe geenaksie getoon, behalwe vir FN, waar die SCA baie hoër was. 11. Om die bogenoemde bevindinge verder te bevestig, is die aditiewe genewerking bereken. Resultate was in ooreenstemming met vorige bevindigs naamlik dat TKM, EX en BFY hoofsaaklik onder aditiewe beheer is, dat FCL, HLM, GPC, LFV, MDT en FPC hoofsaaklik aditief maar ook nie-aditiewe genewerking besit en dat FN en SDS onder nie-aditiewe genetiese beheer staan. 12. 'n Fenotipiese korrelasie matriks is uitgevoer om vas te stelof 'n positiewe of negatiewe korrelasie tussen die kwaliteit- en opbrengs-eienskappe bestaan. Betekenisvolle positiewe korrelasies is verkry tussen HLM en TKM, EX en MDT, GPC en FPC, SDS en LFV, BFY en LFV, EX en MDT, FPC en LFV en FCL en MDT. Dit impliseer dat wanneer vir een van die eienskappe geselekteer word, die ander ook sal verhoog in 'n gunstige omgewing. Nie een van die korrelasies stem ooreen met die ouerproef nie. Betekenisvolle negatiewe korrelasies is gevind tussen TKM en GPC en EXen FCl, wat impliseer dat seleksie vir een van hierdie eienskappe die ander negatief sal beïnvloed. 13. 'n Genetiese korrelasiematriks is ook uitgevoer. Betekenisvolle positiewe korrelasies is gevind tussen SOSen FN (0.858*), MDT en HLM (0.815*) en LFV en FPC(0.824*) wat beteken dat In toename in enige van hierdie eienskappe 'n toename in die ander tot gevolg sal hê ongeag die invloede van die omgewing. In die fenotipiese korrelasie matriks was hierdie korrelasies ook positief, maar nie betekenisvol nie. 14. Die breë en nou sin oorerflikheid is ook bereken vir die kwaliteit- en opbrengseienskappe. Die nou-sin oorerflikheid het gevarieër van so hoog as 0.7089 vir TKM tot 0 vir SDSen FN. Hierdie bevindinge dui weereens op 'n goeie sukses wanneer vir hoër TKM geselekteer word. Die breë sin oorerflikheid was relatief hoog vir die meeste van die eienskappe wat dui op betekenisvolle omgewings invloede in die nie-aditiewe of heterotiese effekte van hierdie gene. 15.lndirekte seleksie is bereken om te bepaal of dit moontlik is om vinniger vordering te maak deur te selekteer vir 'n gekorreleerde eienskap in plaas van direk vir die verlangde eienskap. Geen een van die indirekte seleksies het hoë respons getoon vir TKM en GPC nie, dus moet hierdie eienskappe eerder deur direkte seleksies verbeter word. Direkte seleksies sal oak beter wees om TKM te verhoog, as gevolg van die negatiewe korrelasie met die ander eienskappe. Geen van die indirek geselekteerde eienskappe kon al die ander eienskappe gelyktydig verbeter nie, maar 'n seleksie vir HLM en MDT het In verhoging in al die ander eienskappe tot gevolg gehad, gehalwe FCL. Direkte seleksie is dus beter om spesifieke eienskappe te verbeter. Indirekte seleksie sal egter die beste wees om vir 'n verhoging in SDS en FN te selekteer.en_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectWheaten_ZA
dc.subjectQualityen_ZA
dc.subjectDiallel analysisen_ZA
dc.subjectParental linesen_ZA
dc.subjectF2 generationen_ZA
dc.subjectEnvironmentally stableen_ZA
dc.subjectCombining abilityen_ZA
dc.subjectHeritabilityen_ZA
dc.subjectCorrelationsen_ZA
dc.subjectResponse to selectionen_ZA
dc.subjectGenotype-environment interactionen_ZA
dc.subjectWheat -- Qualityen_ZA
dc.subjectDissertation (M.Sc. (Agric. (Plant breeding))--University of the Free State, 1999en_ZA
dc.titleIdentification of genetic variation in bread wheat quality characteristics in the Western Capeen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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