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dc.contributor.advisorMaartens, H.
dc.contributor.advisorVan Deventer, C. S.
dc.contributor.authorVan Zyl, Christiaan Jacobus
dc.date.accessioned2018-09-10T11:54:48Z
dc.date.available2018-09-10T11:54:48Z
dc.date.issued2001
dc.identifier.urihttp://hdl.handle.net/11660/9272
dc.description.abstractEnglish: 1. The objective of this study was to determine the combining ability of several tomato genotypes, the correlation and heritability between several yield and quality characteristics and the expression of heterosis in the hybrids. 2. Six parental lines and three testers were used in a Line x Tester analysis. Crosses were made in glasshouses at the University of the Free State (UFS). The F1 hybrids and their parental lines were planted in glasshouses at the UFS with three replications. Several yield and quality characteristics were measured ,§lndanalysed. 3. Significant differences were found between the parents for all characteristics measured. Significant differences were recorded between crosses, except for unmarketable yield. KOM 1 x RIN 1 ranked first for total and marketable yield, while the parental line, RIN 3, ranked first for shelf life. Significant differences were found between the lines, except for unmarketable yield, average fruit size and sugar-content (day 16). Significant differences were found among the line x testers, except for unmarketable yield, fruit pH (day 1,4 and day 12) and sugar-content (day 1, 8 and day 20). 4. The parental line KOM 1 proved to be the best general combiner for both total and marketable yield, while F1B was the best general combiner for average fruit mass, average fruit size and shelf life. Parental line R 1 was the best general combiner for fruit pH and sugar-content over the different days. 5. Crosses F1B x RIN 1, RDP 1 x RIN 2 and KOM 2 x RIN 3 were the best specific combiners for total and marketable yield, while RDP 1 x RIN 2 was also the best specific combiner for average fruit mass and average fruit size. KOM 2 x RIN 2 proved to the best specific combiner for the quality characteristics as it had the most positive effects followed by KOM 1 x RIN 1. 6. The specific combining ability (SCA) variance of the study was found higher than the general combining ability (GCA) variance for all the traits except for sugar-content. This means that a large part of the total genetic variability sugar-content. This means that a large part of the total genetic variability was the result of non-additive gene action. 7. Marketable yield showed a significant positive genetic correlation with total yield and average fruit size with fruit mass. Shelf life showed negative genetic correlations for all the traits, except for average fruit size. 8. All the traits had low broad-sense and very low narrow-sense heritabilities. Marketable yield (h²n = 0.06) had the highest narrow-sense heritability for the yield characteristics and fruit pH (h²n = 0.08) the highest for the quality characteristics. 9 Eleven hybrids expressed positive mid-parent (MP) heterosis and five hybrids expressed positive high-parent (HP) heterosis for total yield. KOM 1 x RIN 1 expressed the highest mid-parent and high-parent heterosis for total yield and marketable yield. Fruit pH had the most hybrids with positive midparent (16) and high-parent (12) heterosis. Heterosis was mostly negative for all the quality characteristics measured, thus indicating the effect of the environment.en_ZA
dc.description.abstractAfrikaans:1. Die doel van hierdie studie was om die kombineervermoë van verskeie tamatie lyne, die korreltasie en oorerflikheid van verskeie opbrengs en kwaliteits eienskappe en die uitdrukking van heterose in die nageslag te bepaal. 2. Ses ouerlyne en drie toetsers was gebruik in 'n Lyn x Toetser analise. Kruisings was gemaak in glashuise by die Universiteit van die Vrystaat (UVS). Die ouer lyne en die F1 basters is uitgeplant in die glashuise by die UVS met drie herhalings. Verskeie opbrengs en kwaliteit eienskappe is gemeet en geanaliseer. 3. Betekenisvolle verskille is gevind tussen die ouers vir al die eienskappe. Daar is ook betekenisvolle verskille gevind tussen die kruisings, behalwe by onbemarkbare opbrengs. KOM 1 x RIN 1 het die hoogste opbrengs by totale en bemarkbare opbrengs getoon, terwyl die ouerlyn, RIN 3, die langste rakleeftyd gehad het. Betekenisvolle verskille is gevind tussen die lyn x toetsers, behalwe by onbemarkbare opbrengs, vrug pH (dag 1, 4 en 12) en suiker-inhoud (dag1, 8 en 20). 4. Die ouerlyn, KOM 1, was die beste algemene kombineerder vir beide totale en bemarkbare opbrengs, terwyl F1B die beste was vir gemiddelde vrugmassa, gemiddelde vruggrootte en rakleeftyd. R 1 was die beste algemene kombineerder vir vrug pH en suiker-inhoud oor die verskillende dae. 5. Die kruisings F1B x RIN 1, ROP 1 x RIN 2 en KOM 2 x RIN 3 was die beste spesifieke kombineerders vir beide totale en bemarkbare opbrengs met ROP 1 x RIN 2 ook die beste spesifieke kombineerder vir gemiddelde vrugmassa en gemiddelde vruggrootte. KOM 2 x RIN 2 was die beste spesifieke kombineerder ten opsigte van die kwaliteitseienskappe met die meeste positiewe effekte gevolg deur KOM 1 x RIN 1. 6. Die spesifieke kombineervermoë (SKV) in die studie was hoër as die ~ algemene kombineervermoë (AKV) vir al die eienskappe behalwe vir suikerinhoud. Dit beteken dat In groot deel van die totale genetiese variasie die resultaat van nie-additiewe geenaksies was.7. Betekenisvolle positiewe genetiese korrellasies tussen bemarkbare en totale opbrengs en tussen gemiddelde vrugmassa en gemiddelde vruggrootte is verkry. Rakleeftyd het negatiewe genetiese korrellasies getoon met al die ander eienskappe, behalwe met gemiddelde vruggrootte. 8. AI die eienskappe het lae breë-sin en baie lae noue-sin oorerflikheid getoon. Bemarkbare opbrengs (h²n = 0.06) het die hoogste noue-sin oorerflikheid van die opbrengs eienskappe getoon en vrug pH (h²n = 0.08) die hoogste vir die kwaliteit eienskappe. 9. Elf F1 basters het positiewe middel-ouer heterose en vyf F1 basters het positiewe beste-ouer heterose getoon vir totale opbrengs. KOM 1 x RIN 1 het die hoogste middel-ouer en beste-ouer heterose getoon vir beide totale en bemarkbare opbrengs. Vrug pH was die eienskap waar die meeste basters positiewe middel-ouer (16) en beste-ouer (12) heterose getoon het. Die kwaliteit eienskappe het meestal negatiewe heterose getoon, wat dui op die groot effek wat die omgewing gehad het op die kwaliteit.en_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectCultivated tomato (Lycopersicon esculentum Mill)en_ZA
dc.subjectTomatoes -- Breedingen_ZA
dc.subjectTomatoes -- Geneticsen_ZA
dc.subjectDissertation (M.Sc.Agric. (Plant Breeding))--University of the Free State, 2001en_ZA
dc.titleThe inheritance and genetic expression of the ripening inhibitor (rin) gene in tomatoen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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