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dc.contributor.advisorLabuschagne, M. T.
dc.contributor.advisorMaartens, H.
dc.contributor.authorVan der Walt, Cornelia
dc.date.accessioned2018-05-17T10:15:48Z
dc.date.available2018-05-17T10:15:48Z
dc.date.issued2000-06
dc.identifier.urihttp://hdl.handle.net/11660/8294
dc.description.abstractEnglish: Cultivars produce proteins in their normal life cycle. Some of these proteins are produced in greater quantities in reaction to cold temperatures in certain cultivars. In this study, 27 wheat cutivars were tested for their protein composition. The proteins produced could be divided into 14 different groups with each group having a certain molecular weight range. These groups were the same for the proteins in the coleoptiles and roots of wheat cultivars. Cold susceptible and tolerant cultivars were compared with each other to evaluate their differences in response to cold. The following was found: In the coleoptiles, the tolerant cultivars gained bands across the 14 groups in reaction to cold temperatures. This was also found in the roots of tolerant cultivars. Two of the susceptible cultivars tested (Adam Tas and SST 66), lost more bands in their coleoptiles across the different groups than they gained. The other two susceptible cultivars tested (Palmiet and Snack) gained more bands than they had lost. All the susceptible cultivars (except Palmiet) gained more bands in their roots in response to cold hardening. Palmiet gained and lost the same number of bands. Most cultivars produced more proteins in response to cold. Although proteins are produced in response to cold, not all the cultivars were able to produce the necessary proteins to make them more tolerant to cold. It was clear that some proteins were produced more in all or most cultivars in reaction to cold, but the susceptible and tolerant cultiavrs produced different proteins. In the coleoptiles, the susceptible cultivars had no change or gained bands in group 3 and group 11 while the tolerant cultivars had no change or lost bands in these groups. The susceptible cultivars lost bands (or there were no change in the number of bands produced) in group 4, group 10, group 12 and group 14. The tolerant cultivars gained bands in these groups in response to cold. In the roots, the susceptible cultivars gained bands (or there were no change in the number of bands produced) in group 5, group 11 and group 14. The cold tolerant cultivars lost bands in these groups. Only in group 2, did the cold susceptible cultivars lose bands, while the tolerant cultivars gained bands. The tolerant cultivars thus gained bands in their coleoptiles, whiel they produced fewer proteins in their roots in response to cold temperatures. The susceptible cultivars, however, produced more proteins in their roots than in their coleoptiles in response to cold. Jacobs (1999) found that some cultivars are susceptible to cold in their coleoptiles, but they are tolerant in their roots. SST 66 is an example of a cultivars that is susceptible to cold in its coleoptiles, but it is tolerant to cold in its roots. If one looks at SST 66, it is seen that this cultivars does not produce proteins in reaction to cold temperatures, thus reacting like a susceptible cultivar in its coleoptiles and like a tolerant cultivar in its roots. The susceptible cultivars produced more dark bands in their roots. Thus, the intensity of proteins increased in the roots of susceptible cultivars. In tolerant cultivars however, the intensity of proteins increased in the coleoptiles. Tolerant cultivars produced three times more dark bands in their coleoptiles than susceptible cultivars. If one looks at the production of certain groups, it is found that more proteins were produced in the coleoptiles of susceptible cultivars in group 6, group 8, group 9, group 10 and group 13. Only group 13 was produced in greater amounts in susceptible cultivars and not in the tolerant cultivars. In the coleoptiles of the tolerant cultivars, group 5 and group 7 were produced in greater amounts. It is however, not present in high amounts in susceptible cultivars. In the roots of cultivars, group 3, group 4, group 5 and group 9 can be correlated with cold temperature as it is produced in greater amounts in both the susceptible and tolerant cultivars. A higher intensity of proteins in group 6, group 13 and group 14 are correlated with susceptibility to cold, as it was only detected in susceptible cultivars. Tolerant cultivars produced these proteins in normal or low amounts in response to cold temperatures. Thus, the proteins with molecular weights of 54,5 - 50 kDa (group 5) and 43.5 - 39 kDa (group 7) could be used to screen for tolerance to cold in the coleoptiles of wheat cultivars, while the proteins with molecular weight of 60 - 55.5 kDa (group 4), 43.5 - 39 kDa (group 7) and 27 - 22.5 kDa (group 10) could be used to screen for tolerance to cold in the roots of wheat cultivars. It is further recommended that breeders discard any lines that show an increase in the production of proteins in their roots in the range of 49 - 44.5 kDa (group 6), 10. 5 - 6 kDa (group 13) and 5 - 0 kDa (group 14).en_ZA
dc.description.abstractAfrikaans: Cultivars produseer proteïene in hulle normale lewens-siklus. Sommige proteine word in groter hoeveelhede geproduseer in koue temperature in sekere cultivars. In hierdie studie is 27 koringcultivars getoets vir hulle proteïen-samestelling. Die proteïene kon ingedeel word in 14 verskillende groepe met elke groep in 'n spesifieke molekulêre gewig-indeling. Die groepe was dieselfde vir proteine van koleoptiele en wortels van die plante. Koue vatbare en tolerante cultivars is vergelyk met mekaar om hulle reaksies op koue-stres te toets. Die volgende is gevind: In die koleoptiele het tolerante cultivars bande bygekry oor die 14 groepe in reaksie op koue. Dieselfde is gevind vir wortels van tolerante cultivars. Twee van die vatbare cultivars wat getoets is (Adam Tas en SST 66) het meer bande verloor in hulle koleoptiele oor die groepe as wat hulle bygekry het. Die ander twee vatbare cultivars wat getoets is (Palmiet en Snack) het meer bande bygekry as wat hulle verloor het. AI die vatbare cultivars, behalwe Palmiet, het meer bande bygekry in hulle wortels as wat hulle verloor het met koue. Palmiet het dieselfde hoeveelheid bande bygekry en verloor. Meeste cultivars het meer proteine geproduseer in reaksie op koue. Alhoewel proteine geproduseer is in reaksie op koue, kon nie al die cultivars genoeg proteine produseer om hulle tolerant te maak vir koue nie. Dit was duidelik dat sommige proteïene meer of in al die cultivars geproduseer is in reaksie op koue, maar die vatbare en tolerante cultivars het verskillende proteïene geproduseer. In die koleoptiele het die vatbare cultivars geen verandering gehad nie, of hulle het bande bygekry in groep 3 en groep 11, terwyl die tolerante cultivars geen verandering gehad het nie, of hulle het bande verloor in hierdie groepe. Die vatbare cultivars het bande verloor (of daar was geen verandering in aantal bande nie) in groepe 5, 11 en 14. Die koue tolerante cultivars het bande verloor in hierdie groepe. Net in groep 2 het die koue vatbare cultivars bande verloor, terwyl die tolerante cultivars bande bygekry het. Die tolerante cultivars het dus bande bygekry in hulle koleoptiele, terwyl hulle minder proteïene in hulle wortels geproduseer het met koue. Die vatbare cultivars het bande bygekry met koue. Die tolerante cultivars het dus bande bygekry in hulle koleoptiele, terwyl hulle minder proteïene in hulle wortels geproduseer het met koue. Jacobs (1999) het gevind dat sekere cultivars vatbaar is vir koue in hulle koleoptiele, maar dat hulle tolerant is in hulle wortels. SST 66 is 'n voorbeeld van' n cultivar wat vatbaar is in die koleoptiele, maar tolerant is in die wortels. As mens kyk na SST 66, dan kan dit gesien word dat die cultivar nie proteïene produseer in reaksie op koue nie, dus reageer dit soos' n vatbare cultivar in sy koleoptiele en tolerant in die wortels. Die vatbare cultivars produseer meer donker bande in hulle wortels. Dus, die intensiteit van die proteïene neem toe in die wortels van vatbare cultivars. In die tolerante :crJItivars neem die intensiteit van die proteïene toe in die koleoptiele. Tolerante cultivars het drie keer meer donker bande in hulle koleoptiele geproduseer as in vatbare cultivars. As mens kyk na die produksie van sekere groepe, is daar gevind dat meer proteïene geproduseer is in die koleoptiele van vatbare cultivars in groepe 6, 8, 9, 10 en 13. Net groep 13 is in groter hoeveelhede geproduseer in vatbare cultivars maar nie in tolerante cultivars nie. In die koleoptiele van tolerante cultivars is grope 5 en 7 in groter hoeveelhede geproduseer. Dit is nie in groot hoeveelhede in vatbare cultivars nie. In die wortels van cultivars was groepe 3, 4, 5 en 9 gekorreleer met koue temperature, omdat dit in groter hoeveelhede geproduseer is in vatbare en tolerante cultivars. On Hoër intensiteit van proteïene in groepe 6, 13 en 14 is gekorreleer met koue vatbaarheid, omdat dit net in vatbare cultivars teenwoordig is. Tolerante cultivars het hierdie proteïene in normale of lae konsentrasies geproduseer met koue behandeling. Dus kan proteïene met molekulêre gewigte van 54.5 - 50 kDa (groep 5) en 43.5 - 39 kDa (groep 7) gebruik word om te toets vir koue toleransie in die koleoptiele van koring-cultivars, terwyl proteïene van of 60 - 55.5 kDa (groep 4),43.5 - 39 kDa (groep 7) en 27 - 22.5 kDa (groep 10) gebruik kan word om te toets vir toleransie vir koue in die wortels van koring-cultivars. Daar word aanbeveel dat telers enige lyne moet uitgooi wat proteïene produseer in die gebied van 49 - 44.5 kDa (groep 6), 10.5 - 6 kDa (groep 13) en 5 - 0 kDa (groep 14).en_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.titleThe expression of cold resistance genes in wheat cultivarsen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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