Browsing by Author "Ritter, E."

Now showing 1 - 6 of 6
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    Cuticular wax composition in Cocos nucifera L.: physicochemical analysis of wax components and mapping of their QTLs onto the coconut molecular linkage map
    (2009) Riedel, M.; Riederer, M.; Becker, D.; Herran, A.; Kullaya, A.; Pena-Rodriguez, L.; Arana-Lopez, G.; Billotte, N.; Rohde, W.; Sniady, V.; Ritter, E.
    Cuticular waxes were extracted from the leaves of a coconut mapping population generated by the controlled cross of an East African Tall and a Rennell Island Tall genotype for the construction of molecular linkage maps. The wax composition was analyzed by capillary gas chromatography/mass spectrometry, and for eight of the wax compounds, their absolute and relative amounts were determined. As reported previously for a different coconut ecotype (Malayan Yellow Dwarf), lupeol methyl ether, isoskimmiwallin, and skimmiwallin were identified as the major components of coconut cuticular wax. The additional compounds were characterized as 3-β-methoxy lupane (lupane methyl ether), lupeol and the acetic acid esters of lupeol, skimmiwallinol, and isoskimmiwallinol, respectively. Minor, nonidentified compounds amounted to some 5% of total wax content and included triterpenoids, sterols, primary alcohols, and fatty acids. The variation detected for parents and progeny with respect to the wax components allowed quantitative trait locus (QTL) analyses for their biosynthetic pathways. A total of 46 QTLs could be mapped onto the coconut linkage map which was extended by amplified fragment length polymorphism and single sequence repeat markers into a high density map with more than 1,000 mapped DNA markers. Several colocated QTLs for different traits were detected reflecting the observed correlations among characters.
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    Linkage mapping and QTL analysis in coconut (Cocos nucifera L.)
    (2000) Herran, A.; Estioko, L.; Becker, D.; Rodriguez, M.J.B.; Rohde, W.; Ritter, E.
    Different DNA marker types were used to construct linkage maps in coconut (Cocos nucifera L.; 2n = 32) for the two parents of the cross Malayan Yellow Dwarf (MYD) × Laguna Tall (LAGT). A total of 382 markers was sufficient to generate 16 linkage groups for each parent. The total genome length corresponded to 2226 cM for the LAGT map and 1266 cM for the MYD map with 4–32 markers per linkage group. Common markers allowed the association of 9 linkage groups for the two parents MYD and LAGT. QTL analysis for the trait early germination identified six loci. These QTLs correlate with early flowering and yield, representing characters which are important in coconut breeding. The co-segregation of markers with these QTLs provides the first opportunity for marker-assisted selection in coconut breeding programmes.
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    Microsatellite-based high density linkage map in oil palm (Elaeis guineensis Jacq.)
    (Springer-Verlag, 2007) Billotte, N.; Marseillac, N.; Risterucci, A.M.; Adon, B.; Brottier, P.; Baurens, F.C.; Singh, R.; Herran, A.; Asmady, H.; Billot, C.; Amblard, P.; Durand Gasselin, T.; Courtois, B.; Asmono, D.; Cheah, S.C.; Rohde, W.; Ritter, E.; Charrier, A.
    A microsatellite-based high-density linkage map for oil palm (Elaeis guinensis Jacq.) was constructed from a cross between two heterozygous parents, a tenera palm from the La Me population (LM2T) and a dura palm from the Deli population (DA10D). A set of 390 simple sequence repeat (SSR) markers was developed in oil palm from microsatellite-enriched libraries and evaluated for polymorphism along with 21 coconut SSRs. A dense and genome-wide microsatellite framework as well as saturating amplified fragments length polymorphisms (AFLPs) allowed the construction of a linkage map consisting of 255 microsatellites, 688 AFLPs and the locus of the Sh gene, which controls the presence or absence of a shell in the oil palm fruit. An AFLP marker EAgg/M-CAA132 was mapped at 4.7 cM from the Sh locus. The 944 genetic markers were distributed on 16 linkage groups (LGs) and covered 1,743 cM. Our linkage map is the first in oil palm to have 16 independent linkage groups corresponding to the plants 16 homologous chromosome pairs. It is also the only high-density linkage map with as many microsatellite markers in an Arecaceae species and represents an important step towards quantitative trait loci analysis and physical mapping in the E. guineensis species.
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    Qtl Analysis of Fruit Components in the Progeny of a Rennell Island Tall Coconut (cocos Nucifera L. ) Individual
    (Springer-Verlag, 2006-01) Baudouin, L.; Lebrun, P.; Konan, J.L.; Ritter, E.; Berger, A.; Billotte, N.
    We Investigated the Genetic Factors Controlling Fruit Components in Coconut by Performing Qtl Analyses for Fruit Component Weights and Ratios in a Segregating Progeny of a Rennell Island Tall Genotype. The Underlying Linkage Map of This Population was already Established in a Previous Study, as well as Qtl Analyses for Fruit Production, which were Used to Complement our Results. The Addition of 53 New Markers (mainly SSRs) Led to Minor Amendments in the Map. A Total of 52 Putative QTLs were Identified for the 11 Traits under Study. Thirty-four of them were Grouped in Six Small Clusters, which Probably Correspond to Single Pleiotropic Genes. Some Additional QTLs Located Apart from these Clusters also had Relatively Large Effects on the Individual Traits. The QTLs for Fruit Component Weight, Endosperm Humidity and Fruit Production were Found at Different Locations in the Genome, Suggesting that Efficient marker-assisted Selection for Yield can be Achieved by Selecting QTLs for the Individual Components. The Detected QTLs Descend from a Genotype Belonging to the "pacific" Coconut Group. Based on the Known Molecular and Phenotypic Differences between "pacific" and "Indo-Atlantic" Coconuts, we Suggest that a Large Fraction of Coconut Genetic Diversity is still to be Investigated by Studying Populations Derived from Crosses between these Groups.