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dc.contributor.advisorLabuschagne, M. T.
dc.contributor.advisorViljoen, C. D.
dc.contributor.authorKassa, Tsige Genet
dc.date.accessioned2017-06-07T07:19:09Z
dc.date.available2017-06-07T07:19:09Z
dc.date.issued2002-12
dc.identifier.urihttp://hdl.handle.net/11660/6344
dc.description.abstractEnglish: Ethiopian or Abyssinian mustard (Brassica carinata A. Braun) is one of the most important oil crops in Ethiopia. Apart from its phylogenetic relationships with other members of the genus Brassica, little information is available for this species. This study explored the genetic diversity and genotype x environment interaction for its possible use in genetic conservation and breeding. Geographical patterns of morphological variations were studied on 258 accessions of B. carinata randomly sampled from different parts of the country using Shannon Weaver diversity index ( H') to estimate the phenotypic diversity index for six morphological traits. The results revealed that the mean diversity index (H') across regions of the country was 0.72±0.06. Polymorphism was high for some of the traits. The mean diversity index (H') for the country across altitudinal classes was H' = 0.71 ± 0.07. Highest mean diversity index was recorded from areas ranging from 2600-280 masl. The centres of diversity appears to be Shewa, Bale and Arsi provinces with due consideration of altitudes. Further exploration and in situ conservation efforts should be undertaken in these regions. Brassica carinata possesses a number of agronomic advantages over other oil seed crops with similar ecological adaptation. However, the oil is considered low quality. Although efforts have been made to improve its quality, much has to be done to use natural variations that might exist within the species for fatty acid composition. The objectives of this study were to determine the oil content and fatty acid composition to determine the range of genetic diversity for these traits, and to select genotypes that can be used in crosses to improve these traits. Ninety-eight Ethiopian grown genotypes were analyzed by CGC to study the variability of fatty acid composition. The analysis revealed a wide variation in fatty acid composition; twenty-six fatty acids were identified. The predominant fatty acids were erucic (6.91-35.05%), linoleic (17.21-28.53%),α -linolenic (10.50-22.52%), and oleic (8.91-24.64%), followed by gadoleic (1.22-10.24%) and palmitic (3.38-16.42%). Palmitic acid had significant positive correlations with stearic acid. Erucic acid showed significant and negative linear correlations with palmitic, stearic, vaccinic, oleic, linoleic, α-linolenic acids and positive correlation with eicosenoic acid. The high oil yielding genotypes were relatively richer in erucic acid content. Oil content ranged from 25 to 48%. Genetic diversity analysis within B. carinata has not been examined with molecular markers. The objective of this study was to investigate the genetic relationships among 39 B. carinata genotypes by the AFLP markers. This study explored the amount of genetic variation for possible use in breeding. Thirty-nine genotypes of B. carinata were analysed using six AFLP primer combinations. A total of 189 polymorphic markers were scored, with an average of 32 markers per primer combination. GDE ranged from 0.346 to 0.639, with a mean of 0.504 ± 0.002. Polymorphism rates ranged from 50 to 80%. UPGMA cluster analysis revealed seven genetically distinct groups of genotypes. The GE interaction and the stability of 14 B. carinata genotypes for seed yield were evaluated at four rain-fed locations, over three years in north-western Ethiopia. The objectives were to estimate the component of variance associated with the first and second order interactions and to determine their effects and to measure the genotypes' stability using different stability statistics; and to compare the stability statistics. The analysis of variance test revealed that the main effects due to years, locations, and the first order interactions (year x location) as well as second order interactions (genotype x year x location) were highly significant. The genotype x location interaction was not significant. This suggests the necessity for increased emphasis on multiple years of testing than more locations. The estimates of variance components involving first order interaction of genotype x year, genotype x location and the error variance were very small. The variance components of the main effects of the genotype and second order interaction of genotype x location x year were very high. positive correlation with eicosenoic acid. The high oil yielding genotypes were relatively richer in erucic acid content. Oil content ranged from 25 to 48%. Genetic diversity analysis within B. carinata has not been examined with molecular markers. The objective of this study was to investigate the genetic relationships among 39 B. carinata genotypes by the AFLP markers. This study explored the amount of genetic variation for possible use in breeding. Thirty-nine genotypes of B. carinata were analysed using six AFLP primer combinations. A total of 189 polymorphic markers were scored, with an average of 32 markers per primer combination. GDE ranged from 0.346 to 0.639, with a mean of 0.504 ± 0.002. Polymorphism rates ranged from 50 to 80%. UPGMA cluster analysis revealed seven genetically distinct groups of genotypes. The GE interaction and the stability of 14 B. carinata genotypes for seed yield were evaluated at four rain-fed locations, over three years in north-western Ethiopia. The objectives were to estimate the component of variance associated with the first and second order interactions and to determine their effects and to measure the genotypes' stability using different stability statistics; and to compare the stability statistics. Mean yield over all locations and years ranged from 1304 to 1541 kg/ha by PGRCIE 210406 and PGRCIE 21163 respectively. The regression of yield on the environmental index resulted in a regression coefficient value ranging from 0.7488- 1.2288. The deviation from regression was non significant for all genotypes. The first two interaction principal component axes of the additive main effects and multiplicative interaction (AMMI) model together accounted between 35.7% and 54.3% of the total genotype x environment interaction of sum of squares for seed yield. The stability analyses identified PGRC/E 20017 and PGRC/E 20112 as more stable genotypes, while PGRC/E 21169 and (4DxZEM-1) x (ZEM-1-AD/88) were specifically adapted to some environments. Spearman's coefficient of rank correlation was performed for each of the possible pair wise comparisons of different stability statistics. Significant rank correlations were observed among some of the stability statistics. These significant rank correlations indicated their effectiveness in detecting stable genotypes over a range of environments. The hierarchical clustering of AMMI adjusted mean yield using UPGMA clustering method grouped the genotypes into five genetically distinct clusters and the environments into three heterogeneous clusters.en_ZA
dc.description.abstractAfrikaans: Etiopiese of Abisiniese mosterd (Brassica carinata A. Braun) is een van die belangrikste olie gewasse in Etiopië. Afgesien van die filogenetiese verwantskappe met ander lede van die genus, is daar min inligting beskikbaar oor hierdie spesie. Hierdie studie het genetiese diversiteit ondersoek en genotipe x omgewings interaksie vir moontlike gebruik in genetiese bewaring en teling. Geografiese patrone van morfologiese variasie is ondersoek vir 258 genotipes van B. carrinata wat toevallig gemonster is van verskillende dele van die land, met die gebruik van die Shannon Weaver diversiteits indeks (H') om die fenotipiese diversiteits indeks vir ses kwalitatiewe eienskappe te bepaal. Die resultate het aangetoon dat die gemiddelde genetiese diversiteits indeks (H') oor areas van die land 0.72±0.06 was. Polimorfisme was ook hoog vir sommige eienskappe. Die gemiddelde diversiteits indeks (H') vir die land oor hoogte klasse was H'=0.71±0.07. Die hoogste gemiddelde diversiteits indeks is gevind in areas wat gewissel het van 2600-2800 meter bo seevlak. Die sentrum van genetiese diversiteit is skynbaar Shewa, Bale en Arssi provinsies, met inagneming van hoogte. Verdere ondersoek en in situ bewarings pogings moet gedoen word in hierdie gebiede. Brassica carrinata het 'n aantal agronomiese voordele bo ander oliesaad gewasse, met soortgelyke ekologiese aanpassing. Die olie word egter as van swak kwaliteit beskou. Alhoewel pogings aangewend is om kwaliteit te verbeter, moet baie nog gedoen word om natuurlike variasie te gebruik wat bestaan binne die spesie vir vetsuur samestelling. Die doelwitte van hierdie studie was om olie inhoud en vetsuur samestelling te bepaal, met die reeks van genetiese variasie wat bestaan binne die material, en om genotipes te selekteer wat gebruik kan word om hierdie eienskappe te verbeter. Agt en negentig Etiopiese genotipes is gebruik om vetsuur samestelling variabiliteit te bepaal met CGC. Die oorheersende vetsure was erusien (6.91-35.05%), linoleïen (17.21-28.53%), a-linoleen (10.50-22.52%) gevolg deur gadoleïen (1.22- 10.24%) en palmitien (3.38-16.42%). Palmitien suur was betekenisvol positief gekorreleer met stearien suur. Erusien suur was betekenisvol negatief gekorreleer met palmitien, stearien, vasien, oleïen, linoleïen en a-linoleen suur en positief gekorreleer met eikosenosien suur. Die hoë olie opbrengs genotipes was relatief ryker aan erusien suur. Olie inhoud het gewissel van 25 tot 48%. Genetiese diversiteit analise binne B. carrinata is nog nooit ondersoek met molekulêre merkers nie. Die doel van hierdie studie was om die genetiese verwantskappe tussen 39 B. carrinata genotipes te bepaal met die gebruik van AFLP merkers. Die studie het die hoeveelheid genetiese variasie ondersoek wat bruikbaar is vir teling. Die 39 genotipes van B. carrinata is geanaliseer met ses AFLP priemstuk kombinasies. 'n Totaal van 189 polimorfiese merkers is geëvalueer met 'n gemiddeld van 32 merkers per priemstuk kombinasie. GDE het gewissel van 0.346 tot 0.639 met 'n gemiddeld van 0.504±0.002. Polimorfisme persentasies het gewissel van 50 tot 80%. UPGMA tros analise het sewe duidelike groepe genotipes identifiseer. Die genotipe omgewing interaksie en die stabiliteit van 14 B. carrinata genotipes vir saad opbrengs is geëvalueer by vier lokaliteite onder veld toestande vir drie jare in noord wes Etiopië. Die doel was om die komponent van variasie te vind wat geassossieer is met die eerste en tweede orde interaksies en hulle effekte, om genotipe stabiliteit te bepaal met verskillende stabiliteits statistiese modelle en om stabiliteits statistieke te vergelyk. met eikosenosien suur. Die hoë olie opbrengs genotipes was relatief ryker aan erusien suur. Olie inhoud het gewissel van 25 tot 48%. Genetiese diversiteit analise binne B. carrinata is nog nooit ondersoek met molekulêre merkers nie. Die doel van hierdie studie was om die genetiese verwantskappe tussen 39 B. carrinata genotipes te bepaal met die gebruik van AFLP merkers. Die studie het die hoeveelheid genetiese variasie ondersoek wat bruikbaar is vir teling. Die 39 genotipes van B. carrinata is geanaliseer met ses AFLP priemstuk kombinasies. 'n Totaal van 189 polimorfiese merkers is geëvalueer met 'n gemiddeld van 32 merkers per priemstuk kombinasie. GDE het gewissel van 0.346 tot 0.639 met 'n gemiddeld van 0.504±0.002. Polimorfisme persentasies het gewissel van 50 tot 80%. UPGMA tros analise het sewe duidelike groepe genotipes identifiseer. Die variansie analise het aangetoon dat hoof effekte was a.g.v. jare en lokaliteite, en eerste orde Gaar x lokaliteit) en tweede orde interaksies (genotipe x jaar x lokaliteit) was hoogs betekenisvol. Die genotipe x lokaliteit interaksie was nie betekenisvol nie. Die nie-betekenisvolle genotipe x lokaliteit interaksie en betekenisvolle genotipe x jaar effek het aangetoon dat meer klem geplaas moet word op meer jare eerder as 'n reeks lokaliteite. Die bepaling van variansie komponente wat eerste orde interaksies wat genotipe x jaar, genotipe x lokaliteit en die fout insluit was baie klein. Die variansie komponente van die hoof effekte van die genotipe en die tweede orde interaksie van genotipe x lokaliteit x jaar was baie hoog. Gemiddelde opbrengs oor alle lokaliteite en jare het gewissel van 1304 tot 1541 kg/ha vir PGRCIE 210406 en PGRCIE 21163 onderskeidelik. Die regressie van genotipe gemiddelde opbrengs op die omgewings indeks het 'n regressie koeffisiënt waarde gegee wat wissel van 0.7488-1.2288. Die afwyking van die regressie was nie betekenisvol vir alle genotipes. Die eerste twee interaksie hoof komponent asse van die AMMI (additive-main-effects-and multiplicative-interaction) saam het tussen 35.6% en 54.3% van die totale genotipe omgewings interaksie som van kwadrate van saad opbrengs verklaar. Die stabiliteits analise het PGRCIE 20017 en PGRS/E 20112 meer stabiel gevind, terwyl PGRCIE 21169 en (4DxZEM-l) x (ZEM-1-AD/88) vir spesifieke omgewings aangepas was. Spearman se koeffisiënt van rangorde korrelasie is uitgevoer vir elke moontlike paarsgewyse vergelyking van verskillende stabiliteits statistieke. Betekenisvolle rang korrelasies is gevind tussen sekere stabiliteits statistieke. Hierdie betekenisvolle rang korrelasies het hulle effektiwiteit aangetoon om stabiele genotipes oor 'n reeks omgewings te bepaal. Die hierargale groepering van AMMI aangepaste gemiddelde opbrengste met die UPGMA tros analise metode het die genotipes ingedeel in vyf geneties verskillende groepe, en die omgewings in drie heterogene groeperings.af
dc.description.sponsorshipEthiopian Agricultural Research Organizationen_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectMustard -- Breeding -- Ethiopiaen_ZA
dc.subjectOilseed plants -- Ethiopiaen_ZA
dc.subjectThesis (Ph.D. (Plant Sciences (Plant Breeding))--University of the Free State, 2002en_ZA
dc.titleGenetic diversity analysis and genotpe x environment interaction in Ethiopian mustard (Brassica carinata A. Braun)en_ZA
dc.typeThesisen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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