Labuschagne, M. T.Pretorius, Z. A.Grobbelaar, Benida2017-05-222017-05-221999-06http://hdl.handle.net/11660/6266English: 1. The aim of this study was to determine if the leaf rust resistance genes Lr2g, Lr34, Lr35 and Lr37 have an effect on the quality and yield characteristics of a cultivar it is incorporated into. 2. Near-isogenic lines (NIL's) of PalmietlLr2g and PalmietlLr34, as well as of Karee/Lr2g, Karee/Lr34, Karee/Lr35 and Karee/Lr37 as 'Neil as all relevant parents, were evaluated for four yield and nine quality characteristics in a field experiment in the central Free State. The experiment was conducted in a randomised block design. 3. Results and conclusions: • The HMW glutenin subunits indicated segregation in BC6, especially in the Palmiet lines. • Thatcher and Palmiet lines with Lr29 had significantly lower thousand-kernel 'Neight values compared to their recurrent parents. • Palmiet NIL's with Lr29 had significantly shorter mixograph mixing time compared to Palmiet. • Karee NIL's with the genes Lr34, Lr35 and Lr37 had significantly better PL-ratio's compared to Karee. • None of the leaf rust resistance genes used in this study had an influence on all the quality characteristics and yield components. • The results suggested that the introduction of foreign genes will not necessarily result in a yield reduction. The only reduction in yield was observed in Karee NIL's containing Lr34. • The two genetic backgrounds responded differently following to incorporation of the same Lr gene. • Some sister NIL's performed better than others, which emphasises the importance of sampling.Afrikaans: 1. Die doel van hierdie studie was om te bepaal of die blaarroes- weerstandspene Lr29, L34, Lr35 en Lr37 'n effek het op die kwaliteit- en opbrengseienskappe van 'n kultivar waarin dit geïnkorporeer word. 2. Naby-isogeniese lyne (NIL) van PalmieULr2g en PalmieULr34,sowel as Karee/Lr2g, Karee/Lr34, Karee/Lr35 en Karee/Lr37 en die relevante ouers, is geëvalueer ten opsigte van vier opbrengs- en nege kwaliteitseienskappe in 'n veldeksperiment in die sentrale Vrystaat. Die ekperiment is uitgevoer in 'n gerandomiseerde blokontwerp en het alle relevante ouers ingesluit. 3. Resultate en gevolgtrekkings: • HMG glutenien-subeenhede het nog 'n sekere mate van segregasie getoon na die sesde terugkruising. • Thatcher en Palmiet lyne met Lr29 het fn betekenisvolle laer duisendkorrelmassa gehad as hul herhalende ouers. • Palmiet NIL met Lr29 het 'n betekenisvolle verlaging in mixogram mengtyd getoon. • Die Karee NIL met die gene Lr34, Lr35 en Lr37 het almal fn betekenisvolle verbetering in die PL-verhouding getoon. • Nie een van die blaarroesweerstandspene wat in die studie gebruik is het 'n invloed op al die kwaliteitseienskappe of opbrengskomponente gehad nie. • Die resultate toon dat opbrengs nie noodwendig verlaag word indien gene vanaf verwante spesies in broodkoringkultivars oorgedra sou word, kon nie bevestig word nie. Slegs Karee derivate met die Lr34 geen het fn laer opbrengs as Karee selfgehad. • Die twee genetiese agtergronde het verskillend gereageer ten opsigte van die inkorparering van dieselfde Lr geen. • Sommige suster NIL het beter gevaar as ander vir sekere eienskappe en het dus is die belang van monstering beklemtoon.enWheatLeaf rust resistanceLr29Lr34Lr35Lr37QualityYieldLeaf rust of wheatWheat -- Breeding -- South AfricaWheat -- Disease and pest resistanceDissertation (M.Sc.Agric. (Plant Breeding))--University of the Free State, 1999DissertationUniversity of the Free State