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1

Eglinton, Jason Konrad. "Novel alleles from wild barley for breeding malting barley (Hordeum vulgare L.) /." Title page, abstact and table of contents only, 2003. http://web4.library.adelaide.edu.au/theses/09PH/09phe313.pdf.

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2

Jefferies, Stephen P. "Marker assisted backcrossing for gene introgression in barley (Hordeum vulgare L.)." Title page, contents and chapter 1 only, 2000. http://web4.library.adelaide.edu.au/theses/09APSP/09apspj45.pdf.

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Bibliography: leaves 183-211. This study evaluates the backcross breeding method for the introgression in barley of agronomically important traits into a malting quality background using molecular markers.
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3

Tinker, Nicholas Andrew. "Studies on the analysis of genetic markers and quantitative trait loci in plant breeding populations." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=41774.

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Laboratory experiments, genetic simulation, and theoretical analyses were performed to address several objectives related to the use of genetic markers in plant breeding programs. Two software packages were developed: GREGOR provides flexible and efficient computer algorithms for performing genetic simulation experiments, and KIN provides improved methods for estimating coancestry from known pedigrees. Random amplified polymorphic DNA (RAPD) markers were investigated in elite barley lines, and estimates of genetic distance based on RAPD markers were compared to estimates based on coancestry. Both types of estimate can provide information that is useful to breeders and geneticists. Genetic simulation was used to investigate the power, accuracy and precision of several methods that are available for analyzing quantitative trait loci (QTL). In most cases, simplified methods of QTL analysis based on linear regression were similar or superior to more complex methods based on mixture models. Methods for genetic analysis using selective genotyping and pooled DNA were also investigated. These methods may allow precise estimates of the positions of markers and QTL to be made.
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4

Jonsson, Rickard. "Breeding for resistance to barley net blotch (Pyrenophora teres) /." Alnarp : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/avh/2001/91-576-5814-5.pdf.

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5

Ahmed, Ahmed Abdul-Jawad. "Studies on barley : genetics and breeding for resistance to leaf blotch Rhynchosporum secalis (OUD.) J.J. Davis." Thesis, University of Hull, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278273.

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6

Visioni, Andrea. "Barley adaptation to stress prone environments." Doctoral thesis, Universitat de Lleida, 2012. http://hdl.handle.net/10803/121581.

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Multi environment trials conducted over mapping population are often used to test genotypes in a set of environments that represent the target environmental range. The first part of this work is the evaluation of the ‘Nure’ x ‘Tremois’ double-­‐haploid mapping population, together with an association panel comprising 185 barley varieties representative of the barley germplasm cultivated in the Mediterranean basin. Plant material was tested across eighteen site by year field trials combination, in six countries across the Mediterranean basin. Trials were growth at sites contrasting for natural rainfall (high vs low on the base of past meteorological data) or at the same site with one being rainfed and the other with supplementary irrigation. Trials conducted for two years in each one of the sites and this allowed tocollect a huge data series comprising agronomical traits defining grain yield and yield components, phenological and environmental data, subsequently used to identify genomic regions involved in barley adaptation. The 118 doubled haploid lines of the mapping population were genotyped with Diversity Array Technology® (DaRT) marker assay and subsequently a total of 15 CAPS and SSCP marker for candidate genes involved in phenology regulation and abiotic stress response were added to the linkage map based on DaRT markers. Data collected were firstly used to perform QTLs analysis with composite interval mapping for any environment/ trait combination, results showed eight QTLs for grain yield, days to heading and grain yield components. . The two mostly frequents QTLs for grain yield and days to heading were located on barley chromosome 1H (3 trials), 2H (8 trials) and 5H (5 trials) overlapping respectively HvFT3 gene, the earliness per se locus (eam6/Eps-­‐2) and the vernalization gene Vrn_H1. A further QTL multi-­‐environment analysis was performed and revealed that across the 18 field trials QTL for eam6/Eps-­‐2 (2H) and Vrn-­‐H1 (5H) were commons for days to heading and grain yield. We use all the environmental information collected to check QTLs sensitivities to co-­‐environmental co-­‐variables. Most of significant associations collected were related to temperature and temperature-­‐based variables troughtout the growing cycle. Eam6/Eps-­‐2 showed non-­‐crossover QTL.E interaction, while for Vrn-­‐H1 crossover interactions were revealed. The 185 barley accession were genotyped with 1536 SNPs and data collected for this population for cold resistance in two field trials in Spain an Italy, the first trial was characterized by an exceptional winter, while the second was previously know has frost-­‐prone environment. Results from genome wide association analysis showed 13 positive associations with specific genomic regions. Interestingly several of these QTL were coincident with the position of previously mapped loci for cold tolerance, on chromosomes 2HL, 4HL and 5HL.
Els assajos en localitats múltiplas de poblacions de mapeo s'utilitzen freqüentment per a testar genotips en un conjunt d'ambients representatius de la condicions climàtiques on es volen introduir aquests genotips. La primera part d'això treball ha estat l'avaluació de la població de mapeo ‘Nure x Tremois’ constituïda de 118 de doble haploides d'ordi, juntament amb panell d'associació que comprèn 185 varietats d'ordi representatives del germoplasma conreat en la conca Mediterrània. El material vegetal ha estat assajat en una combinació de divuit camps per any desllorigats en sis països de la conca mediterrània. Els assajos s'han portat a terme en camps amb diferent disponibilitat d'aigua, classificats sobre la base de les dades relatives a les freqüència i quantitat de les precipitacions o en el mateix lloc amb un camp en secà i altre regat. Els assajos es van portar a terme per dos anys en cada localitat i això va permetre la recollida d'un gran volum de dades que comprenen caràcters agronómicos relacionats amb rendiment i components del rendiment, dades fenológicos i ambientals. Aquestes dades es van utilitzar després per a la identificació de regions genomicas involucrades en l'adaptació de l'ordi a l'ambient. Els 118 dobles haploides de la població ‘Nure x Tremois’ es genotiparon amb marcadors DaRT (Diversity Array Technology), després un set de 15 marcadors CAPS I SCCP per a gens candidats involucrats en la regulació de les fases fenológicas van ser afegits al mapa de lligament construït amb els marcadors DaRT. Les dades van ser utilitzats per a fer una anàlisi de QTL amb procediment ‘Composite Interval Mapping’ para cada combinació ambienti/ caràcter. Es van trobar diversos QTLs per rendiment i data d'espigolat i components del rendiment. Els QTL mes freqüents trobats per rendiment i data de floració i components del rendiment estan localitzats en els cromosomes 1H (3 camps), 2H (8 camps) i 5H (5 camps) coincidents respectivament amb HvFT3 locus, eam6/Eps-­‐2 (earliness per se) locus i amb el locus de vernalización Vrn-­‐H1. Una ulterior anàlisi de QTL feta amb el mètode “Multi Environment Trial” ha revelat que els QTL localitzats en el locus eam6/Eps-­‐2 (cromosoma 2H) i Vrn-­‐H1 (cromosoma 5H) són comunes per rendiment i data de floració en els 18 camps d'assaig. Per això utilitzem tots el dades ambientals col·leccionades durant tot el cicle del cultiu per a investigar la sensibilitat de dites QTL a les co-­‐variables ambientals. La majoria de les associacions oposades estan relacionades amb temperatures i variables relacionades amb aquestes. Eam6/Eps-­‐2 mostra una interacció de tipus quantitatiu amb aquestes variables mentre Vrn-­‐H1 mostra una interacció de tipus qualitatiu amb aquestes variables. Les 185 varietats assajades van ser genotipadas amb 185 SNPs i fenotipadas per resistència a fred en dos assajos uneixo a Espanya i altre a Itàlia. El primer assaig va ser caracteritzat per un hivern excepcionalment fred, mentre el d'Itàlia ha estat utilitzat en passat per testar resistència a fred a causa de els hiverns rígids que solen registrar-­‐se en aquesta localitat. Les dades van ser utilitzats per a portar a terme la analisis GWAS “Genome Wide Association Analysis” . Els resultats van permetre identificar 13 regions genomicas involucrades en la resistència a frio. Entre elles tres regions coincideixen amb loci ja mapeados i coneguts per ser involucrats en la resposta a frio en los cromosomes 2HL, 4HL i 5HL.
Los ensayos en localidades múltiplas de poblaciones de mapeo se utilizan frecuentemente para testar genotipos en un conjunto de ambientes representativos de la condiciones climáticas donde se quieren introducir dichos genotipos. La primera parte de esto trabajo ha sido la evaluación de la población de mapeo ‘Nure x Tremois’ constituida de 118 de doble haploides de cebada, junto con panel de asociación que comprende 185 variedades de cebada representativas del germoplasma cultivado en la cuenca Mediterránea. El material vegetal ha sido ensayado en una combinación de dieciocho campos por año dislocados en seis países de la cuenca mediterránea. Los ensayos se han llevado a cabo en campos con diferente disponibilidad de agua, clasificados en base a los datos relativos a las frecuencia y cantidad de las precipitaciones o en el mismo sitio con un campo en secano y otro regado. Los ensayos se llevaron a cabo por dos años en cada localidad y esto permitió la recogida de un gran volumen de datos que comprenden caracteres agronómicos relacionados con rendimiento y componentes del rendimiento, datos fenológicos y ambientales. Dichos datos se utilizaron después para la identificación de regiones genomicas involucradas en la adaptación de la cebada al ambiente. Los 118 dobles haploides de la población ‘Nure x Tremois’ se genotiparon con marcadores DaRT (Diversity Array Technology), después un set de 15 marcadores CAPS Y SCCP para genes candidatos involucrados en la regulación de las fases fenológicas fueron añadidos al mapa de ligamento construido con los marcadores DaRT. Los datos fueron utilizados para hacer una análisis de QTL con procedimiento ‘Composite Interval Mapping’ para cada combinación ambiente/ carácter. Se encontraron varios QTLs por rendimiento y fecha de espigado y componentes del rendimiento. Los QTL mas frecuentes encontrados por rendimiento y fecha de floración y componentes del rendimiento están localizados en los cromosomas 1H (3 campos), 2H (8 campos) y 5H(5 campos) coincidentes respectivamente con HvFT3 locus, eam6/Eps-­‐2 (earliness per se) locus y con el locus de vernalización Vrn-­‐H1. Una ulterior análisis de QTL hecha con el método “Multi Environment Trial” ha revelado que los QTL localizados en el locus eam6/Eps-­‐2 (cromosoma 2H) y Vrn-­‐H1 (cromosoma 5H) son comunes por rendimiento y fecha de floración en los 18 campos de ensayo. Por esto utilizamos todos lo datos ambientales coleccionadas durante todo el ciclo del cultivo para investigar la sensibilidad de dichos QTL a las co-­‐variables ambientales. La mayoría de las asociaciones encontradas están relacionadas con temperaturas y variables relacionadas con estas. Eam6/Eps-­‐2 muestra una interacción de tipo cuantitativo con dichas variables mientras Vrn-­‐H1 muestra una interacción de tipo cualitativo con dichas variables. Las 185 variedades ensayadas fueron genotipadas con 185 SNPs y fenotipadas por resistencia a frío en dos ensayos uno en España y otro en Italia. El primer ensayo fue caracterizado por un invierno excepcionalmente frío, mientras el de Italia ha sido utilizado en pasado por testar resistencia a frío debido a los inviernos rígidos que suelen registrarse en dicha localidad. Los datos fueron utilizados para llevar a cabo la analisis GWAS “Genome Wide Association Analysis”. Los resultados permitieron identificar 13 regiones genomicas involucradas en la resistencia a frio. Entre ellas tres regiones coinciden con loci ya mapeados y conocidos por ser involucrados en la respuesta a frio en los cromosomas 2HL, 4HL y 5HL.
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7

Dunford, Roy Patrick. "Molecular aspects of albinism in anther culture derived barley plants." Thesis, University of Leicester, 1989. http://hdl.handle.net/2381/34406.

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Haploid cereal plants can be regenerated from single pollen grains via the process of anther culture. Anther culture of cereals is of potential use in crop improvement programmes. One problem associated with anther culture of cereal plants is a high incidence of albino individuals which cannot be used in crop breeding schemes. Albinos derived from barley anther culture (albino pollen plants) are severely pigment deficient and from electron microscopy studies appear to possess plastids that are developmentally arrested at a stage prior to the differentiation of proplastids to mature chloroplasts. The aim of the project has been to investigate some of the molecular aspects of albinism in these individuals. In vitro propagation experiments were carried out to find the conditions necessary to improve the growth and maintenance of albino pollen plants with the objective of producing a continuous supply of albino tissue for molecular analysis. However, use of various media containing organic and inorganic supplements including a number of plant growth regulators failed to improve the growth of albino plants. Southern analysis revealed that four out of the five albino plants studied exhibit ptDNA restriction patterns that are different to that expected from the wild type map of the barley plastid genome due to the alteration or deletion of specific ptDNA fragments. One plant appears to contain a major form of ptDNA that has undergone a deletion event removing 75% of all sequences. This confirms that the albino pollen plants examined in this study contain forms of the plastid genome that have undergone structural alteration. I have termed these variant plastid genomes ptDNAs. Most of the albino plants studied appear to contain heterogenous populations of ptDNAs. One albino barley pollen plant appears to possess an intact plastid genome. For all the albinos studied the overall levels of ptDNA are reduced 5-15 fold compared to the levels found in normal green tissues. Northern analyses revealed that the transcripts from the ptDNA genes rbcL and psbD-psbC do not accumulate or are present in albino tissues at 5-10% the level found in seed-derived green shoots. Levels of the plastid encoded 16S and 23S rRNAs are similarly reduced in albino tissues. Further Northern analysis revealed that the abundance of transcripts from the nuclear genes rbcS and cab are present in most albino plants at 10% the level found in normal green tissues. Southern analysis indicated that the nuclear DNA restriction fragments encompassing the cab and rbcS genes in two albino plants had not been altered or deleted during the anther culture process. Analysis of green pollen plants indicated that they contain ptDNA of apparently normal structure and abundance and accumulate transcripts from plastid genes and nuclear genes encoding chloroplast polypeptides to the same levels found in the leaves of light grown seedlings. These results represent the first determination of the levels of photosynthetic gene expression in both albino and green pollen plants.
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8

Eggers, Ben. "Identifying phenotypic traits critical for breeding winter malting barley adapted to Ohio and the genomic regions affecting those traits." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1607035449218475.

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9

Dayteg, Christophe. "Automation of molecular markers in practical breeding of spring barley (Hordeum vulgare L.) /." Alnarp : Department of Plant Breeding and Biotechnology, Swedish University of Agricultaral Sciences, 2008. http://epsilon.slu.se/2007132.pdf.

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10

Pandey, Madhav Prasad. "Molecular assessment of genetic diversity and population differentiation of hulless barley (Hordeum vulgare L.) landraces from the Himalayas of Nepal and its relevance for barley breeding." Göttingen : Cuvillier, 2006. http://geb.uni-giessen.de/geb/volltexte/2007/3880/index.html.

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11

Johnston, Paul Andrew, and n/a. "Molecular characterisation of chromatin introgressed from Hordeum bulbosum L. into Hordeum vulgare L." University of Otago. Department of Biochemistry, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080215.161403.

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Hordeum bulbosum L. (bulbous barley grass) is an important genetic resource for barley (Hordeum vulgare L.) improvement. As the sole member of the secondary genepool of Hordeum; H. bulbosum represents a relatively untouched source of genetic diversity which can provide novel allelic variation for traits critical to the future of barley breeding. In order to access this resource efficiently, a complete set of molecular marker resources is necessary to assist the introgression of chromatin from H. bulbosum into a barley genetic background. For breeders to access traits from H. bulbosum for barley improvement, recombinant lines need to be developed to transfer regions of the H. bulbosum genome into a barley background for trait identification and for incorporation into elite barley breeding programs. The chromosomal location of H. bulbosum introgressions in thirty eight unique recombinant lines was performed using RFLP analysis using mostly distal probes from barley genetic linkage maps However, this analysis was labour intensive, restrictive and prone to inconsistencies due to low intensity signals and complex banding in H. bulbosum. Due to the low level of interspecific recombination detected between the two species, a retrotransposon-like marker, pSc119.1, was developed which could be used to quickly screen progeny from an interspecific cross to determine which lines possessed introgressions of chromatin from H. bulbosum. After initial screening, putative recombinants were further characterised using co-dominant single locus PCR markers from throughout the genome. A focus was made on using the EST resources of barley and wheat, combined with the rice genome to create intron-spanning markers. Subsequent allele-sequencing revealed high frequencies of species-diagnostic single nucleotide polymorphisms (SNPs) in the intron regions of these markers, coupled with relatively low frequencies of species-diagnostic SNPs in the flanking exon regions. Overall, interspecific SNP frequencies were not significantly higher in intron-spanning markers than those consisting of exon-only sequence. However, species-diagnostic indels were more frequently discovered within intron sequence providing additional polymorphism. Recombinant lines with phenotypes that differed from the barley parent allowed those traits to be assigned to particular chromosomal regions. These characterised recombinant lines will provide a resource for barley breeders to identify novel traits for barley improvement and allow identification of new alleles in different chromosomal locations for current traits, allowing greater flexibility for cultivar construction. A targeted backcross population of the recombinant line 38P18/8/1/10 (possessing leaf rust resistance derived from H. bulbosum) was created. The introgressed region was saturated for PCR markers using a variety of marker types and techniques (AFLP, cDNA-AFLP). Two lines were subsequently identified with introgressions of reduced size relative to the parental recombinant line, both of which have retained the leaf rust resistance trait. The leaf rust resistance was finally linked to two co-dominant EST-based markers located on chromosome 2HL by using these two lines and the direct screening of progeny from interspecific hybrids possessing introgression junctions in the region of interest. In general, recombinant material between barley and H. bulbosum suffers from certation effects which cause distorted segregation that favours heterozygous and homozygous barley genotypes. Two unique lines have been identified during this research that possess gametocidal-type loci that result in the absolute retention of H. bulbosum chromatin with the termination of gametes lacking the introgression (barley genotype only).
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Kolodinska, Brantestam Agnese. "A century of breeding - is genetic erosion a reality? : temporal diversity changes in Nordic and Baltic barley /." Alnarp : Dept. of Crop Sciences, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/200530.pdf.

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13

Pandey, Madhav Prasad [Verfasser]. "Molecular assessment of genetic diversity and population differentiation of hulless barley (Hordeum vulgare L.) landraces from the Himalayas of Nepal and its relevance for barley breeding / vorgelegt von Madhav Prasad Pandey." Göttingen : Cuvillier, 2007. http://d-nb.info/988662728/34.

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14

Poulsen, David Malcolm Ernest. "Application of molecular markers to breeding barleys for disease resistance /." St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17378.pdf.

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15

Collins, Nicholas C. "The genetics of barley yellow dwarf virus resistance in barley and rice." Title page, table of contents and summary only, 1996. http://hdl.handle.net/2440/46063.

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Barley yellow dwarf virus (BYDV), an aphid transmitted luteovirus, is the most widespread and economically damaging virus of cereal crops. The work in this thesis aims to characterise the basis of the naturally occurring resistance to BYDV in cereals in three ways: Firstly, by facilitating the isolation of the Yd2 gene for BYDV resistance from barley by a map-based approach. Secondly, by determining if a BYDV resistance gene in rice is orthologous to Yd2. Thirdly, by establishing if other BYDV resistance genes in non- Ethiopian barleys are allelic to Yd2. It is hoped that the information generated in this study will ultimately assist in the production of BYDV resistant cereal cultivars. A detailed genetic map of the Yd2 region of barley chromosome 3 was constructed, containing 19 RFLP loci, the centromere and the Yd2 gene. Yd2 mapped on the long arm, 0.5 cM from the centromere, and in the mapping population of 106 F2 individuals, perfectly cosegregated with the RFLP loci XYlp, and Xwg889. This map represents the first stage in a project to isolate the Yd2 gene by a map-based approach. The isolation of Yd2 could help to elucidate the molecular mechanism of the Yd2-mediated BYDV resistance, and may allow the production of BYDV resistant cereals by genetic transformation. The RFLP markers mapped closest to Yd2 could also be useful in barley breeding, by enabling selection for both the presence of Yd2 and the absence of agronomically undesirable traits known to be closely linked to Yd2. Genetically Directed Representational Difference Analysis (GDRDA) is a technique based on subtractive hybridisation, which can be used to identify RFLP markers closely linked to a gene of interest. Two GDRDA experiments were performed with the intention of generating additional RFLP markers close to Yd2. However, the first experiment yielded RFLP probes that were not derived from the barley genome, while the second experiment yielded probes that detected repetitive sequences. It was concluded that GDRDA is of limited use in generating further markers close to Yd2. To isolate the Yd2 gene by a map-based approach, a much larger mapping population will need to be analysed to genetically resolve markers tightly linked to Yd2. If the two morphological markers uzu dwarf and white stripe,,j flank Yd2, then they could assist in this task by enabling the visual identification of F2 seedlings resulting from recombination close to Yd2. However, in this study, both morphological markers were found to be located distal to Yd2. Therefore, these two morphological markers can not be used together to facilitate high resolution genetic mapping of the Yd2 locus. It may be possible to use large-insert genomic DNA clones from the relatively small genome of rice to generate further RFLP markers close to the Yd2 gene in barley, provided that the order of orthologous sequences in barley and rice is conserved close to the Yd2 locus. To assess the feasibility of this approach, RFLP probes used to identify loci close to Yd2 were mapped in rice using a segregating rice F2 population. Five of the RFLP loci mapped together and in the same order as RFLP loci mapped close to Yd2 in barley using the same probes. By comparing the location of RFLPs mapped by other researchers in rice using probes mapped close to Yd2, the region of conserved linkage between rice and the Yd2 region was tentatively identified as the central portion of rice chromosome 1. The collinearity shown by orthologous sequences in barley and rice indicated that it may indeed be possible to use rice to assist in generating RFLP markers close to Yd2. Of all the cereals, rice is the most amenable to map-based gene isolation, due to its small genome, well developed physical and genetic maps, and its ability to be genetically transformed with high efficiency. If a BYDV resistance gene that is orthologous to Yd2 could be identified in rice, this gene could be isolated with relative ease, and then used to identify barley cDNA clones corresponding to Yd2 gene by virtue of the sequence homology expected between these genes. To test if a BYDV resistance gene from an Italian rice line is orthologous to Yd2, recombinant-inbred rice lines previously characterised for this gene were analysed using probes mapped close to Yd2 in barley. No genetic linkage was detected between the RFLP loci and the BYDV resistance gene, indicating that the gene is unlikely to be orthologous to Yd2. BYDV resistance alleles at the Yd2 locus which are of a non-Ethiopian origin may show interesting differences to Ethiopian Yd2 resistance alleles. To identify barleys which may contain resistance alleles of Yd2, ten BYDV resistant barleys not known to contain Yd2 were assessed for their resistance to the PAVadel isolate of BYDV in the glasshouse. CI 1179, Rojo, Perry, Hannchen, Post and CI 4228 were found to be the most resistant under these conditions, and were analysed further. If the resistance from these barleys is controlled by alleles of Yd2, RFLP markers close to Yd2 will be expected to cosegregate with the resistance in F2 families derived from crosses between these resistant barleys and the BYDV susceptible barleys Atlas and Proctor. RFLPs suitable for use in these allelism tests were identified using probes mapped close to Yd2. However, time did not permit the analysis of these F2 populations.
Thesis (Ph.D.) -- University of Adelaide, Dept. of Plant Science, 1996
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16

Jenkin, Mandy Jane. "Genetics of boron tolerance in barley /." Adelaide : Thesis (Ph.D.) -- University of Adelaide, Department of Plant Science, 1993. http://web4.library.adelaide.edu.au/theses/09PH/09phj514.pdf.

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17

Harvey, Andrew John. "Isolation, characterization and differential expression of Barley B-Glucan Exohydrolase genes." Title page, abstract and table of contents only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phh399.pdf.

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On title page "B" is superscript. Bibliography: leaves 112-135. The primary aims of the work described in this thesis were to isolate and characterize the cDNAs that correspond to the two B-glucan exohydrolases designated isoenzyme ExoI and isoenzyme ExoII. (abstract)
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18

Caldwell, Katherine Selby. "An evaluation of the patterns of nucleotide diversity and linkage disequilibrium at the regional level in Hordeum vulgare /." Title page, table of contents and abstract only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phc1471.pdf.

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19

Smith, Ryan Anthony. "Germination and growth responses of Hordeum Vulgare SV13 cultivated as a green fodder crop for African conditions." Thesis, Cape Peninsula University of Technology, 2018. http://hdl.handle.net/20.500.11838/2790.

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Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2018.
This study evaluated the effects of 5 different soaking treatments in conjunction with 5 varying irrigation intervals on the germination, growth and nutritional values of seed of Hordeum vulgare Sv13. The 5 different soaking times consisted of 1, 3, 8, 16 and 24 hours. The barley seed was first cleaned and then placed in a vessel containing 500 ml of distilled water with a 20 % solution of sodium hypochlorite (bleach) at room temperature. Thereafter the pre-soaked seeds were transferred to a perforated container, containing no medium and placed into a growing chamber equipped with drip irrigation. The seed was then irrigated with 1245 ml of water at 5 different intervals namely every 2, 4, 8 10 and 12 hours. The temperature of the hydroponic growing room was kept at a constant 23 °C using a hotoperiod of 16-hour day/ 8-hour darkness. The seed was allowed to germinate and grow for a period of 8 days before being harvested. The objectives of this study were to determine the most beneficial combination of soaking treatment in conjunction with the most beneficial irrigation interval on the germination rate of the seed allowing for radicle emergence and coleoptile production. It was also used to determine which combination of treatments was most beneficial to the growth and nutritional values of the seed post-harvest. Another objective was to ascertain the shortest soaking time for application in a small-scale, hydroponic growing unit as well as the frequency of irrigation required to grow seedlings, thereby determining the amount of water required to produce a seedling mat for a small-scale, subsistence farmer, with the emphasis being on water reduction. Each treatment was replicated 10 times and consisted of 500 grams of seed, which when placed into its container measured 2 centimetres in depth, totalling 25 treatments in all. Germination was measured by observing radicle emergence in the first 2 days of the growing period first after a 24-hour cycle and again after 48 hours. The numbers of leaves present at harvest after an 8-day growing period were also counted to determine germination rate of the seeds. Growth was determined by average leaf height as well as the tallest leaf on day 8 of the growing cycle. Root mat expansion was also measured, post-harvest, which was compared to the initial 2 cm planting depth of seed. Wet and dry weights of the plant material were measured post-harvest. Samples of the harvested material were also sent for nitrogen and protein analysis. It was discovered that most of the results favoured a shorter soaking time and an increase in irrigation frequency, bar a few exceptions. Most favoured a pre-soaking time of only 1 hour together with an irrigation frequency of between 2 and 4 hours. This shows that small-scale farmers would be able to reduce the time spent on soaking of their seed. Although the frequency of the irrigation interval remained high further testing would be required to determine if the amount of water applied at each irrigation interval could be reduced and still produce favourable results. It would also remain to be seen if no irrigation during the 8-hour dark photoperiod would have any negative impact on germination, growth and nutritional values of the seedlings.
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20

Patil, Vrushali. "Molecular developmental genetics of the barley internode." Thesis, University of Dundee, 2016. https://discovery.dundee.ac.uk/en/studentTheses/a7e7046a-3615-40c4-b678-200299cd0d12.

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21

Qian, Jiajing. "Effects of Hordeum vulgare and Hordeum bulbosum genotypes, seed age, culture methods and plant growth regulators on barley haploid production." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56678.

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Four experiments were conducted with the objectives of (i) comparing the suitability of various H. bulbosum clones for haploid production, (ii) determining the parental effects of H. bulbosum and barley genotypes on percentage of pollinated florets yielding caryopses with rescuable embryos and on embryo viability, (iii) comparing different stages for embryo culture and caryopsis culture, and (iv) attempting to produce barley haploids directly from cultured immature caryopses. The results demonstrated: that reproductive characteristics of H. bulbosum clones varied with environmental conditions; that the hybrid H. bulbosum clones MBC-3 and MBC-4 were superior to their parents Cb2920 and Cb2929 as pollen donors; that both parental genotypes and date of harvesting after pollination had large effects on percentage of pollinated florets yielding caryopses with rescuable embryos and on embryo viability; that haploid plantlets can be generated from haploid caryopsis culture without embryo rescue, but only at a low frequency and with a slow rate of germination.
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22

Hidayat, Imam. "Evolution and spread of paraquat resistant barley grasses (Hordeum glaucum Steud. and H. leporinum Link) /." Title page, abstract and table of contents only, 2004. http://web4.library.adelaide.edu.au/theses/09PH/09phh6323.pdf.

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23

Hunter, Clifford Paul. "Plant regeneration from microspores of barley Hordeum vulgare L." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/7765.

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24

King, Brendon James. "Towards cloning Yd2 : a barley resistance gene to barley yellow dwarf virus." Title page, contents and summary only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phk523.pdf.

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25

Fernández, José. "Anther and pollen development in barley." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/13916/.

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The control of pollen viability and release is of major commercial importance in the development of crops for hybrid seed production and selective breeding. It has been shown that key transcription factors in Arabidopsis particularly MALE STERILITY1 (MS1), are functionally conserved in rice (Li et al., 2011), therefore extending this comparative analysis and controlling fertility in temperate cereals, such as barley, is the long term goal of this project. Although anther and pollen development of barley seems morphologically similar to Arabidopsis, the genes involved and how they are regulated are currently unknown. Arabidopsis MS1 is a tapetum specific transcription factor which is expressed exclusively from the tetrad stage to early microspores release. Identification and accurate staging of barley anther development is essential for expression analysis and functional characterisation of genes involved in pollen development. Therefore, a complete morphological study of barley development was conducted. External characteristics have been described in parallel to anther development in order to predict anther stages by the observation of external stages phenotypic traits. Characterization of the barley orthologue of MS1 (HvMS1) has been conducted. Recently a new grass genome has been released, Brachypodium distachyion. This new resource has been used to aid primers design alongside the rice OsPTC1 sequence, the orthologue of MS1 (Li et al., 2011). Genome sequencing has indicated that the Brachypodium genus is more closely related to wheat and barley than it is to rice, Due to the close relationship between Brachypodium and barley, this new grass has been used as intermediary to identify the OsPTC1 orthologue in barley as well as downstream MS1 targets. A highly similar sequence to OsPTC1 was found in Brachypodium, Bradi4g31760. This new gene, as a result of its similarities to OsPTC1, was considered as its putative orthologue gene in Brachypodium. Therefore, the most conserved areas between OsPTC1-Bradi4g31760 were used for primers design to successfully amplify equivalent gene in barley (HvMS1). The characterization of this barley gene showed a similar expression pattern to the MS1 putative orthologue in Arabidopsis of tapetum specific expression. In addition, RNAi silencing of this gene has revealed that it is essential for the normal development of pollen, with a lack of viable pollen produced in the putative HvMS1 silenced transgenic lines.
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26

Cartwirght, Ewen James. "Barley mild mosaic virus : deletions, duplication and transmission." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285557.

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27

Finnie, Susan Jane. "The development and utilisation of anther culture technology in barley breeding." Thesis, University of Edinburgh, 1990. http://hdl.handle.net/1842/14853.

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In this thesis, the potential of barley anther culture as a method for the rapid and efficient production of homozygous lines has been investigated. The substitution of sucrose by maltose in the anther culture medium led to a substantial improvement in the frequency of green plant regeneration. High concentrations (6-12%) of maltose gave greater number of green plants than low (1-3%) concentrations. In addition, plant regeneration was predominantly via an embryogenic route rather than an intermediate callus phase. Three commercially important spring barley cultivars, Tweed, Tyne and Natasha were considered. All three responded on a maltose-based medium, although to differing extents. The genetic stability of anther culture-derived lines produced by this method was assessed by karyotype analysis, and by using a range of biochemical and molecular markers. Low levels of variation were detected and the relative stability of the system may be attributed to the embryogenic mode of regeneration attained on a medium containing maltose. Despite the improvements obtained using the maltose protocol, response to anther culture was shown to be largely dependent on genotype. An investigation of the transmission of anther culture responsiveness into F1 hybrids produced from H.vulgare x H.spontaneum crosses showed that responsiveness was dominant to non-responsiveness. A high degree of heterosis for anther culture response was also observed in F1 progenies. An investigation of anther culture response in the wheat/barley disomic chromosome addition lines showed that addition of a single pair of barley chromosomes could not positively modify anther culture response in an unresponsive wheat background. The implications of these results are discussed in relation to the application of anther culture technology to barley breeding and genetics.
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28

Lonergan, Paul Francis. "Genetic characterisation and QTL mapping of zinc nutrition in barley (Hordeum vulgare)." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phl847.pdf.

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29

Campbell, Graham F. (Graham Findlay). "Genetics of pathogenicity in Pyrenophora leaf diseases of barley." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52286.

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Dissertation (PhD(Agric)) -- University of Stellenbosch, 2001.
ENGLISH ABSTRACT: Net blotch of barley, caused by Pyrenophora teres, is one of the most important diseases of this cereal in the south Western Cape Province of South Africa. This fungus exists as two different types (forms), namely a nettype and a spot-type that are distinguished by differential symptom expression on barley leaves. Based on this specific plant pathological difference a series of studies of agricultural importance were executed to investigate the effects of sexual recombination between these two types. In addition, studies were done to determine the difference between local net- and spot-type populations with regards to population structure and fungicide sensitivity. This dissertation therefore, consists of a collection of separate publications and as a result a certain degree of redundancy has been unavoidable. Recombination is one of the most important evolutionary forces involved with sexual reproduction. In plant-fungal agricultural ecosystems this may result in pathogenic fungal populations adapting more rapidly to control programs such as fungicide applications. The first section of the review in part 1 of this dissertation covers different aspects of sexual reproduction in ascomycetes, specifically focussing on mating-type genes, vegetative incompatibility and recombination. The major part of the review is then dedicated to various plant pathological aspects of P.teres, specifically addressing the differences between the two types, and in various cases highlighting the significance of sexual recombination within and between the net- and spot-type. Using morphological criteria for identification purposes there have been many conflicting reports concerning the identity of leaf spot isolates in the Western Cape Province of South Africa. In part 2, the correct identity was eventually achieved employing mating studies and molecular markers .: This was accomplished after single ascospores were obtained from pseudothecia after in vitro mating had occurred between a verified P. teres net-blotch isolate from Denmark and a representative Pyrenophora leaf spot isolate from South Africa. Using amplified fragment length polymorphism (AFLP) and RAPD markers, recombination was demonstrated in the progeny that had DNA banding patterns different from the two parental isolates. Pathogenicity trials also confirmed that recombination had taken place during mating. Inoculations were conducted on the differential cultivars susceptible to the net-blotch and leaf spot forms. The two parents induced typical net-blotch or leaf spot symptoms whereas the progeny mostly induced a jagged spot symptom on each cultivar. Fungicide sensitivity tests using the ergosterol biosynthesis inhibitors showed that, due to recombination, some progeny could have increased resistance to these fungicides. Due to mating and subsequent recombination between a net blotch isolate of P. teres and a representative leaf spot isolate, it was concluded that the latter was P. teres f. maculata. Fifteen of the net-spot hybrid progeny (F1) produced from the mating study in Part 2 were screened in Part 3 to assess their viability and genetic stability. Hybrid progeny (F1) inoculated onto barley seedlings consisting of the cultivars Stirling (differentially susceptible to net-type isolates), B87/14 and Clipper (both differentially susceptible to spot-type isolates) produced intermediate symptoms on all cultivars. Axenic cultures (F1-1) isolated from foliar lesions, followed by repeated inoculation and isolation (F1-2) onto a healthy set of seedlings produced similar intermediate symptoms. RAPDs conducted with two 1Q-mer primers on all isolates of F1-1and F1-2progeny revealed profiles similar to those obtained for F1 isolates. RAPD molecular data, therefore, indicated that hybrid progeny of this net x spot mating were genetically stable after having been subjected to two repetitive inoculation and reisolation cycles. Phylogenetic analysis of DNA sequences of the internal transcribed spacers (ITS1 and ITS2) flanking the 5.8S nuclear ribosomal RNA gene and the 5' end partial histone-3 gene confirmed the genetic stability of the hybrid progeny. These results also indicated that the hybrid progeny produced consistent symptoms throughout the series of experiments, and maintained their virulence to the differential cultivars screened. Both types of P. teres are prevalent in the south Western Cape Province of South Africa, found on susceptible cultivars often grown within close proximity of each other. In Part 4, a net- and spot-type population were characterised in terms of their population structure using RAPD markers. Samples were collected from infected barley leaves from two separate quadrants in each field, the two quadrants positioned in corners of the fields, diagonal to one another. A total of 65 loci were produced of which 54 were polymorphic. Total gene diversities determined for all loci resulted in mean indices of 0.063 and 0.082 being obtained respectively for the net- and spottype populations. A coefficient of genetic differentiation (Gs) of 0.0149 was obtained between sites within populations while a coefficient (GT) of 0.63 was obtained between the two populations. Genotypic variation revealed 13 distinct multilocus genotypes (haplotypes) in the net-type population while there were 12 in the spot-type population. UPGMA cluster analysis done on the two populations together with six progeny from the mating between a netand spot-type isolate resulted in three main clusters being produced, one for each population and one for the progeny. One isolate collected from the nettype population also contained a unique spot-type RAPD fragment. This suggested that sexual recombination may be taking place between isolates of the net- and spot-type under field conditions. Fungicide application is the most important method used in the control of net blotch in South Africa. In Part 5 the fungicide sensitivities (ICsD values) of 89 monoconidial isolates (46 net-type and 43 spot-type) of P. teres to sterol demethylation inhibiting fungicides were determined, based on the inhibitory effect on radial mycelial growth. The fungicides evaluated were triadimenol, bromuconazole, flusilazole, propiconazole and tebuconazole. Both net- and spot-type isolates revealed strong resistance to triadimenol while flusilazole was shown to be the strongest inhibitor of fungal growth. Spot-type isolates showed a higher resistance than net-type isolates to all five fungicides screened. The ICsD values indicated significant differences between four of the fungicides (triadimenol, tebuconazole, flusilazole and propiconazole). The ICsD values between propiconazole and bromuconazole were not significant. This study suggested that spot-type isolates showed a higher degree of resistance to commercially used fungicides than net-type isolates. The overall conclusion of this study is that the spot-type of P. teres is the pathogen associated with leaf spots of barley in the south western Cape province of South Africa and not P. japonica as earlier reported. Together with the net-type, both types exist as genetically variable populations in this barley production region. Mating between the two types results in sexual progeny that are genetically stable. This implies that barley fields adjacent to one another in which either net- or spot-type susceptible cultivars are being cultivated may lead to sexual progeny being produced. This in turn may lead to an increased rate at which fungal populations may become resistant to commercially used fungicides. It is furthermore suggested that an alternative fungicide seed treatment is used instead of triadimenol due to high resistance of P. teres to this fungicide.
AFRIKAANSE OPSOMMING: Netvlek op gars is een van die belangrikste siektes van hierdie graansoort in die suidelike deel van die Westelike Kaapprovinsie. Dié siekte word veroorsaak deur die swam Pyrenophora teres. Hierdie swam kom voor as twee verskillende tipes, naamlik 'n net-tipe en 'n kol-tipe wat onderskei word op grand van die voorkoms van hulle simptome op garsblare. Hierdie planpatologiese verskil in ag genome, is 'n reeks studies van landboukundige waarde uitgevoer om die effek van geslagtelike rekombinasie tussen die twee tipes te ondersoek. Daarbenewens is ook studies uitgevoer om om die verskil te bepaal tussen plaaslike net- en koltipe populasies ten opsigte van populasiestruktuur en fungisiedsensitiwiteit. Hierdie verhandeling bestaan dus uit 'n versameling afsonderlike publikasies en as gevolg daarvan is daar onvermydelik'n mate van oorvleueling. Rekombinasie is een van die belangrikste evolusionêre kragte betrokke by geslagtelike voortplanting. In plant-swam landboukundige ekostelsels kan dit veroorsaak dat patogene swampopulasies vinniger aanpas by beheerpragramme soos fungisiedtoediening. Die eerste gedeelte in deel 1 van hierdie verhandeling dek die verskillende aspekte van geslagtelike voortplanting van ascomycetes, met spesifieke verwysing na paringstipe gene, vegetatiewe onverenigbaarheid en rekombinasie. Die grootste gedeelte van die oorsig word gewyaan verskeie plantpatologiese aspekte van P. teres,en wys veralop die verskille tussen die twee tipes. In verskeie gevalle word die betekenis van geslagsrekombinasie binne en tussen die net- en koltipe uitgelig. Deur morfologiese kenmerke vir identifikasiedoeleindes te gebruik, is daar baie teenstrydige verslae rakende die identifikasie van blaarvlekisolate in die Westlike Kaapprovinsie van Suid-Afrika. In deel 2 is die korrekte identifikasie eventueel verkry deur gebruik te maak van paringstudies en molekulêre merkers. Dit is bereik nadat enkel ascospore verkry is uit pseudothecia gevorm na in vitro paring plaasgevind het tussen 'n bevestigde P. teres netvlek isolaat uit Denemarke en 'n verteenwoordigende Pyrenophora blaarvlekisolaat van Suid- Afrika. Deur gebruik te maak van versterkte fragmentlengte polimorfisme [AFLP] en RAPD merkers, is rekombinasie gedemonstreer in die nasate wat DNA bandpatrone gehad het wat verskil het van dié van die "ouer" isolate. Patogenisiteitstoetse het ook bevestig dat rekombinasie tydens paring plaasgevind het. Inokulasies is uitgevoer op die verskillende cultivars wat vatbaar is vir die netvlek en blaarvlek vorme. Die twee ouers het tipiese netvlek of blaarvlek simptome veroorsaak, terwyl die nasate hoekige vlekke veroorsaak het op elke cultivar. Toetse vir fungisiedsensitiwiteit deur gebruik van die ergosterol biosintese inhibeerders het gewys dat a.g.v. rekombinasie sekere nasate verhoogde weerstand teen hierdie fungisiedes het. As gevolg van paring en daaropvolgende rekombinasie tussen 'n netvlek isolaat van P. teres en 'n verteenwoordigende blaarvlek isolaat is afgelei dat laasgenoemde P. teres f. maculata is. Vyftien van die netvlek hibried nakomelinge (F1) verkry van die paringstudie in deel 2 is ondersoek in deel 3 om hul lewensvatbaarheid en genetiese stabiliteit te bepaal. Hibried nasate (F1) geïnokuleer op garssaailinge bestaande uit die volgende cultivars: Stirling (soms vatbaar vir net-tipe isolate) , B87/14 en Clipper (albei soms vatbaar vir kol-tipe isolate) het intermediêre simptome op al die cultivars veroorsaak. Akseniese kulture (F1-1) geïsoleer uit blaarletsels gevolg deur herhaalde inokulasie en isolasie (F1-2) op 'n gesonde stel saailinge het dieselfde intermediêre simptome veroorsaak. RAPDs uitgevoer met twee 10-mer inleiers op al die isolate van F1-1 en F1-2 nasate het profiele opgelewer soortgelyk aan dié wat vir F1 isolate verkry is. RAPD molekulêre data het dus gewys dat die hibried nasate van hierdie net x kol paring geneties stabiel was nadat dit onderwerp is aan twee inokulasie en reïsolasie siklusse. Genetiese stabiliteit van die hibried nageslag is bevestig deur filogenetiese analise van die DNA volgorde van die interne getranskribeerde spasieerders (ITS1 en ITS2) reg langs die 5.8S nukluêre ribosomale RNA geen en die 5' end gedeeltelike histoon-3 geen. Hierdie resultate het ook gewys dat die hibried nasate konstante simptome getoon het tydens die hele reeks eksperimente en hulle virulensie behou het vir die kultivars wat getoets is. Beide tipes van P. teres kom algemeen voor in die suidelike deel van die Westelike Kaapprovinsie en word gevind op vatbare cultivars wat dikwels naby mekaar groei. In deel 4 is 'n net- en kol-tipe populasie gekarakteriseer in terme van hulle populasiestruktuur deur gebruik van RAPD merkers. Monsters is versamel van geïnfekteerde garsblare van twee aparte kwadrante in elke saailand. Die twee kwadrante is geplaas in die hoeke van die saailand, diagonaal tot mekaar. 'n Totaal van 65 lokusse is gevorm, waarvan 54 polimorfies was. Die algehele genetiese verskeidenheid bepaal vir alle lokusse, het gelei tot gemiddelde indekse van 0.063 en 0.082 soos gevind vir die net- en kol-tipe populasies. 'n Koëffisiënt van genetiese differensiasie (Gs ) van 0.0149 is gevind tussen gebiede tussen populasies, terwyl 'n koëffisiënt (GT) van 0.63 gevind is tussen die twee populasies. Genotipiese variasie het 13 duidelike multilokus genotipes (haplotipes) getoon in die net-tipe populasie, terwyl daar twaalf was in die kol-tipe populasie. UPGMA groeperingsanalises wat gedoen is op die twee populasies tesame met ses nasate van die paring van 'n net- en koltipe isolaat het tot gevolg gehad dat drie hoof groepe gevorm is, een vir elke populasie en een vir die nasate. Een isolaat wat versamel is, van die net-tipe populasie het 'n unieke kol-tipe RAPD fragment bevat. Dit wys daarop dat geslagtelike rekombinasie in veldomstandighede mag voorkom tussen isolate van die net- en kol-tipe. Fungisiedtoediening is die belangrikste metode wat gebruik word om netvlek in Suid-Afrika te beheer. In deel 5 is die fungisiedsensitiwteit (Ieso waardes) van 89 enkelkonidiale isolate (46 net-tipe en 43 kol-tipe) van P. teres teen sterol demetielasie inhiberende fungisiedes bepaal, op die basis van die onderdrukkende effek op die radiale groei van die miselium. Die volgende fungisiedes is geëvalueer: triadimenol, bromuconazole, flusilazole, propiconazole en tebuconazole. Beide net- en kol-tipe isolate het 'n sterk weerstand teen triadimenol openbaar, terwyl flusilazole gevind is as die sterkste onderdrukker van swamgroei. Kol-tipe isolate het 'n hoër weerstand as die net-tipe isolate teen al vyf fungisiedes wat getoets is, gehad. Die lesowaardes het aangedui dat daar beduidende verskille tussen vier van die fungisiedes IS (triadimenol, tebuconazole, flusilazole en propiconazole). Die leso waardes tussen propiconazole en bromuconazole was nie beduidend nie. Die gevolgtrekking van hierdie studie is dus dat die kol-tipe isolate 'n hoër graad van weerstand teen kommersiëel gebruikte fungisiedes as die net-tipe isolate gehad het. Die algehele gevolgtrekking van hierdie studie is dat die kol-tipe van P. teres, die patogeen is wat geassosieer word met blaarvlekke op gars in die suidwestelike Kaapprovinsie van Suid-Afrika, en nie P. japonica soos voorheen gerapporteer nie. Tesame met die net-tipe, kom altwee tipes voor as geneties veranderlike populasies in hierdie gars verbouingstreek. Paring tussen die twee tipes lei tot geslagtelike nasate wat geneties stabiel is. Dit impliseer dat aangrensende garsvelde waarop net- óf kol-tipe vatbare kultivars verbou word, mag lei tot die produksie van geslagtelike nasate. Dit kan weer lei tot 'n verhoogde tempo waarteen swampopulasies weerstandbiedend teenoor kommersiële fungisiedes raak. Daar word verder ook voorgestel dat alternatiewe fungisied saadbehandelings gebruik word in plaas van triadimenol as gevolg van verhoogde weerstand van P. teres teenoor laasgenoemde.
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30

Al-Hassen, Ibrahim Saker. "Genetic control of alcohol dehydrogenase in barley Hordeum vulgare." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.257161.

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31

Tan, Han-Qi. "Dissecting barley malting quality QTLs with maize Ac/Ds transposons." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97247.

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Malting quality of barley is a complex but important trait for the malting and brewing industries. Several malting quality QTLs have been located on the chromosome 4H of barley. However, the genes associated with these QTLs regions are unknown. The Ac/Ds transposon system was used to dissect these malting quality QTLs. New single-copy Ds insertion lines (TNPs) were generated through sequential re-activation of Ds transposon in the candidate parental lines – TNP-29 and -79, in which the Ds insertion sites were mapped in the vicinity of the malting quality QTLs on chromosome 4H. Reactivation of Ds was carried out by crossing these TNPs with AcTPase expressing plants as well as through in-vitro expression of AcTPase in immature barley embryos. Furthermore, a new PCR based approach – HE-TAIL PCR was devised to expedite the detection of new transposition events. This study will contribute to a better understanding of genes involved in the barley malting quality.
La qualité du malt de l'orge est un trait complexe mais important pour les secteurs du maltage et de l'industrie brassicole. Plusieurs QTLs associés à la qualité du malt sont localisés sur le chromosome 4H de l'orge. Cependant, les gènes associés à ces QTLs sont inconnus. Par conséquent, nous avons utilisé le système de transposons Ac/Ds afin de caractériser ces QTLs. De nouvelles lignées comprenant une insertion unique de l'élément Ds (TNPs) ont donc été produites grâce à la réactivation séquentielle du transposon Ds chez des lignées reconnues comme ayant un élément Ds unique à proximité de ces QTLs. La réactivation de l'élément Ds a été réalisée en croisant les lignées parentales TNP-29 et TNP-79 avec une lignée exprimant l'AcTPase ainsi que par l'insertion par transformation de l'AcTPase chez des embryons immatures obtenus à partir de ces mêmes lignées. De plus, nous avons développé l'approche HE-TAIL PCR afin d'accélérer la détection de nouveaux événements de transposition. Par conséquent, mes travaux contribuent à améliorer notre compréhension des mécanismes impliqués dans la régulation de la qualité du malt de l'orge.
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32

Ward, Michael Patrick. "Biochemistry, genetics and molecular biology of nitrite reduction in barley." Thesis, University of St Andrews, 1997. http://hdl.handle.net/10023/14341.

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Nitrite reduction is the third step of the nitrate assimilation pathway in higher plants and is catalysed by nitrite reductase. The whole-plant barley mutants STA1010, STA2760 and STA4169 accumulate nitrite in the leaf after treatment with nitrate and, like the nir1 mutant STA3999 (Duncanson et al, 1993), lack detectable nitrite reductase cross-reacting material in the leaf and root. STA1010, STA2760 and STA4169 carry a recessive mutation in a single nuclear gene, identified as the Nir1 locus. RFLP analysis of the nir1 mutant STA3999 has allowed the Nir1 locus to be mapped to within 0.3cM of the nitrite reductase apoprotein gene, Nii. Studies to confirm the identity of the Nir1 locus as Nii, by establishing the full-length Nii cDNA sequences from STA3999 and from its wild-type cv Tweed for comparative purposes, were unsuccessful as attempts to isolate a Nii cDNA clone from a barley cv Tweed cDNA library yielded only partial-length Nii clones. These nirl mutants display greatly reduced nitrite reductase activity and increased NADH-nitrate reductase activity in the leaf, as compared to wild-type plants, suggesting a regulatory perturbation in the expression of the Nar1 gene. Northern analysis shows that the nir1 mutants possess nitrite reductase apoprotein (nii) transcript of wild-type size (2.3kb) and at approximately wild-type levels. Since nir1 mutants possess a phenotype that might be anticipated for a Nii mutant, it is likely that the nir1 mutation is present in the nitrite reductase apoprotein gene Nii and affects translation of the nii transcript. Studies of barley wild-type cv Golden Promise have demonstrated that nitrite reductase in leaf tissue is up-regulated by a coaction of nitrate and light which acts, at least partly, at the transcriptional level.
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33

Jenkin, Mandy Jane. "Genetics of boron tolerance in barley / by Mandy Jane Jenkin." Thesis, Adelaide Thesis (Ph.D.) -- University of Adelaide, Department of Plant Science, 1993. http://hdl.handle.net/2440/21652.

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34

Jenkins, R. E. "Developmental studies in relation to anther culture in Hordeum vulgare." Thesis, University of East Anglia, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374688.

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35

Oppong-Konadu, Eden Y. "Evolution in genetically diverse populations of barley (Hordeum vulgare L.)." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336773.

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36

Bull, Hazel Joanne. "Identification and characterisation of the barley row-type gene VRS3." Thesis, University of Dundee, 2015. https://discovery.dundee.ac.uk/en/studentTheses/be5f6de8-4245-45e3-bb17-649f7d724f55.

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Barley row-type describes the number of grains present at a node on the barley spike. Two forms exist amongst cultivated barley: two-rowed with only the central of three spikelets fertile producing a single grain at a node and six-rowed with all three spikelets fertile, producing three grain at a node. Twelve regions of the barley genome have been associated with the row-type character with specific genes identified at three loci, VRS1, VRS4 and INT-C. Advancements in the understanding of the genetic control underpinning barley row-type enables the identification of potential mechanisms for improving yield and yield architecture within the cereals.  This study used genetic linkage mapping in segregating F2 populations to refine the genetic location of the row-type locus, VRS3, to 16 candidate genes on barley chromosome 1H. Sequencing candidate loci in 32 vrs3 induced mutant alleles identified VRS3 to be a highly conserved JmjC histone demethylase, with two natural alleles within European cultivated barley. VRS3 was further characterised as a potential means of improving grain uniformity within cultivated six-rowed barley, through phenotypic assessment of grain size in varying allele combinations of VRS3, VRS1 and INT-C. The addition of six-rowed alleles at these loci was found to improve balance between central and lateral grain parameters, resulting in a more uniform grain sample. Analysis of gene expression found Vrs3 to be constitutively expressed across a diverse panel of barley tissues. Moreover, detailed study within the developing inflorescence suggests a role for Vrs3 in the regulation of the row-type genes VRS1 and INT-C.
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37

Golegaonkar, Prashant G. "Genetic and molecular analysis of resistance to rust diseases in barley." University of Sydney, 2007. http://hdl.handle.net/2123/3549.

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Doctor of Philosophy
The responses of 92 barley genotypes to selected P. hordei pathotypes was assessed in greenhouse tests at seedling growth stages and in the field at adult plant growth stages to determine known or unknown resistances. On the basis of multipathotype tests, 35 genotypes were postulated to carry Rph2, Rph4, Rph5, Rph12, RphCantala alone or combinations of Rph2 + Rph4 and Rph1 + Rph2, whereas 52 genotypes lacked detectable seedling resistance to P. hordei. Five genotypes carried seedling resistance that was effective to all pathotypes tested, of which four were believed to carry uncharacterised resistance based on pedigree information. Field tests at adult plant growth stages indicated that while 28 genotypes were susceptible, 57 carried uncharacterised APR to P. hordei. Pedigree analysis indicated that APR in the test genotypes could have been derived from three different sources. The resistant responses of seven cultivars at adult plant growth stages were believed to be due to the presence of seedling resistance effective against the field pathotypes. Genetic studies conducted on 10 barley genotypes suggested that ‘Vada’, ‘Nagrad’, ‘Gilbert’, ‘Ulandra (NT)’ and ‘WI3407’ each carry one gene providing adult plant resistance to P. hordei. Genotypes ‘Patty’, ‘Pompadour’ ‘Athos’, ‘Dash’ and ‘RAH1995’ showed digenic inheritance of APR at one field site and monogenic inheritance at a second. One of the genes identified in each of these cultivars provided high levels of APR and was effective at both field sites. The second APR gene was effective only at one field site, and it conferred low levels of APR. Tests of allelism between resistant genotypes confirmed a common APR gene in all genotypes with the exception of ‘WI3407’, which based on pedigree information was genetically distinct from the gene common in ‘Vada’, ‘Nagrad’, ‘Patty’, ‘RAH1995’ and ‘Pompadour’. An incompletely dominant gene, Rph14, identified previously in an accession of Hordeum vulgare confers resistance to all known pathotypes of P. hordei in Australia. The inheritance of Rph14 was confirmed using 146 and 106 F3 lines derived from the crosses ‘Baudin’/ ‘PI 584760’ (Rph14) and ‘Ricardo’/‘PI 584760’ (Rph14), respectively. Bulk segregant analysis on DNA from the parental genotypes and resistant and susceptible DNA bulks from F3 lines using diversity array technology (DArT) markers located Rph14 to the short arm of chromosome 2H. Polymerase chain reaction (PCR) based marker analysis identified a single simple sequence repeat (SSR) marker, Bmag692, linked closely to Rph14 at a map distance of 2.1 and 3.8 cM in the populations ‘Baudin’/ ‘PI 584760’and ‘Ricardo’/‘PI 584760’, respectively. Seedlings of 62 Australian and two exotic barley cultivars were assessed for resistance to a variant of Puccinia striiformis, referred to as BGYR, which causes stripe rust on several wild Hordeum species and some genotypes of cultivated barley. With the exception of six Australian barley cultivars and an exotic cultivar, all displayed resistance to the pathogen. Genetic analyses of six Australian barley cultivars and the Algerian barley ‘Sahara 3771’, suggested that they carried either one or two major seedling resistance genes to the pathogen. A single recessive seedling resistance gene, Bgyr1, identified in ‘Sahara 3771’ was located on the long arm of chromosome 7H and flanked by restriction fragment length polymorphism (RFLP) markers wg420 and cdo347 at genetic distances of 12.8 and 21.9 cM, respectively. Mapping resistance to BGYR at adult plant growth stages using a doubled haploid population derived from the cross ‘Clipper’/‘Sahara 3771’ identified two major QTLs on the long arms of chromosomes 3H and 7H that explained 26 and 18% of total phenotypic variation, respectively. The QTL located on chromosome 7HL corresponded to the seedling resistance gene Bgyr1. The second QTL was concluded to correspond to a single adult plant resistance gene designated Bgyr2, originating from cultivar ‘Clipper’.
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38

Voltas, Velasco Jordi. "Barley improvement and yield constraints in Mediterranean environments: binterfacing crop physiology with plant breeding." Doctoral thesis, Universitat de Lleida, 1998. http://hdl.handle.net/10803/8345.

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L'ordi (Hordeum vulgäre L.) és un cereal de zones temperades conreat extensament en
climes mediterranis. Es desenvolupa favorablement en àrees de pluviometria mitjana anual
superior a 250 mm. Durant les darreres dècades, els increments en rendiment deguts a activitats
de millora genètica han estat poc importants a causa, probablement, de la limitació que la sequera
i altres estressos abiòtics exerceixen sobre el creixement. Futurs increments poden veure's
accelerats per un millor coneixement dels processos que controlen el creixement i
desenvolupament i que limiten la product! vi tat dels genotips en situacions de manca d'aigua. Dins
d'aquest contexte, les activitats d'investigació en fisiologia vegetal haurien de tenir un fort
impacte, en un futur proper, en l'increment de l'eficiència dels programes de millora tradicionals.
Aquesta tesi pretén ampliar el coneixement actual d'aquells factors que redueixen el creixement,
la productivitat i la qualitat de l'ordi en ambients mediterranis. Amb aquesta finalitat, s'han
avaluat en assajos localitzats a la província de Lleida (nordest d'Espanya) i, ocasionalment, a les
províncies de Navarra (nord d'Espanya) i Valladolid (centre d'Espanya), un conjunt de deu
genotips d'ordi (incloent-hi dos i sis carreres) que difereixen en adaptació a ambients semiàrids.
Inicialment, un conjunt de tres genotips moderns i altament productius (Barberousse,
Orria i Plaisant) va ésser utilitzat per examinar l'efecte que una reducció de l'embomal
reproductiu (nombre de grans per espiga) provocava sobre el pes i el creixement del gra,
l'acumulació de carbohidrats i el transport de nitrogen en condicions semiàrides (Capítols I i II).
Els increments en pes de gra obtinguts en resposta a una reducció del 50% de l'embornal van ser
progressivament superiors en aquells ambients amb grans testimoni de menor pes. Pel contrari,
el nitrogen es va acumular uniformement en tots els ambients en resposta a una reducció de
l'embornal. Aquests resultats suggereixen que el rendiment final es troba fortament limitat, en
ambients productivament pobres, per la disponibilitat de carbohidrats durant l'omplenat del gra,
en tant que l'acumulació de proteïnes en el gra sembla independent de les condicions ambientals
en que té lloc l'omplenat del gra. El grau de limitació exercit per la font es va manifestar més
elevat en els grans situats en espigúeles laterals de l'espiga, amb independència de la
disponibilitat d'assimilats per l'omplenat del gra. Aquest desavantatge dels grans laterals de
l'espiga es va poder atribuir principalment a taxes d'acumulació de matèria seca inferiors durant
l'omplenat.
La influència d'estressos abiòtics com ara la sequera o les altes temperatures en el procés
d'omplenat dels grans es va examinar en detall utilitzant el conjunt dels deu genotips assajats en
dotze ambients (Capítols III i IV). L'objectiu final va consistir a detectar variabilitat genètica així
com determinar possibles mecanismes morfofisiològics de tolerància als esmentats estressos. Els
possibles factors causants d'interacció genotip-ambient (G*E) en el pes del gra, tasa i duració
d'omplenat es van estudiar mitjançant l'ús de models estadístics biadditius. Es van detectar
sensibilitats genotípiques diferencials en tolerància a sequera i a elevades temperatures de postantesi
pel pes final del gra, que varen atribuir-se parcialment a diferències entre els grups d'ordis
de dos i sis carreres. La presència de GxE per a la taxa d'omplenat es va explicar per l'efecte
conjunt de variables climàtiques de pre-antesi, la qual cosa va suggerir que les diferències
genotípiques podrien ser degudes parcialment a diferències en el balanç font/embornal entre ordis
de dos i sis carreres en antesi. L'existència de GXE per a la duració d'omplenat va poder-se
atribuir principalment a diferències en data d'antesi entre genotips, indicant l'existència d'una
estratègia d'escapament causant d'un allargament del période d'omplenat d'alguns genotips a
finals del cicle de cultiu.
La relació entre rendiment i discriminació isotòpica del carboni (A) en grans va avaluar-se
extensament en un grup de 22 ambients (Capítol VI), i també va examinar-se la possibilitat
d'utilització de la concentració de cendres en teixits aeris com a substitut de A (Capítol VII).
L'expressió genotipica del rendiment va estar condicionada per l'ambient d'una forma més
important que la de A. L'existència de GxE pel rendiment va suggerir la presència d'una
interacció qualitativa amb un punt de creuament aproximat situat en productivitats mitjanes
inferiors a 3 t ha"1. Pel contrari, la classificació de genotips per a A no va variar substancialment
amb l'ambient. En general, aquells genotips amb valors baixos de A i, per tant, amb elevades
eficiències de transpiració, van ésser superiors en ambients poc productius (ambients per sota de
3 t ha"1), en tant que valors genotípics de A elevats van mostrar-se com avantatjosos en ambients
de rendiment mig i alt. És probable que, quan la sequera sigui moderada, un important embornal
reproductiu forci la planta a incrementar la seva conductancia estomàtica i, com a conseqüència,
l'aigua total utilitzada. Aquest fenomen probablement capgira la relació negativa esperada entre
A i biomassa o rendiment quan la disponibilitat d'aigua és factor limitant. Per altra banda, la
concentració mineral en grans va trobar-se relacionada freqüentment i de forma negativa amb A,
en tant que no va trobar-se relació entre la concentració mineral en palla i A. Aquests resultats
suggereixen que l'acumulació mineral en teixits aeris mostrejats a finals del cicle de cultiu és
independent de l'eficiència de transpiració durant l'omplenat del gra. La concentració de cendres
en grans podria emprar-se com a criteri de selecció complementari a A en ambient semiàrids, si
bé es fa necessari un coneixement fisiologie més profund dels mecanismes que afecten
l'acumulació de minerals en el gra.
La sequera esdevé el principal factor limitant del creixement i la productivitat de l'ordi
en els secans semiàrids mediterranis. En el present estudi, les diferències en productivitat en un
conjunt de 22 ambients van poder atribuir-se, en gran part, a diferències paral·leles en
disponibilitat hídrica des de sembra fins a antesi, période en el qual es determina el nombre de
grans per m2. La presència d'una interacció GXE de tipus qualitatiu pel rendiment, així com les
relacions fluctuants entre rendiment i A, depenent de la intensitat de l'estrès hídric, suggereixen
que la tolerància a la sequera i l'elevat potencial de rendiment son conceptes antagònics en ordi.
La cebada (Hordeum vulgäre L.) es un cereal de zonas templadas ampliamente cultivado
en climas mediterráneos. Se desarrolla favorablemente en zonas de pluviometría media anual
superior a 250 mm. Durante las últimas décadas, los incrementos en rendimiento debidos a
actividades de mejora genética han sido poco importantes probablemente a causa de la limitación
que la sequía y otros estreses abióticos ejercen sobre el crecimiento. Futuros incrementos pueden
verse acelerados por un mejor conocimiento de los procesos que controlan el crecimiento y
desarrollo y que limitan la productividad de los genotipos en situaciones caracterizadas por la
falta de agua. En este contexto, las actividades de investigación en fisiología vegetal deberían
tener un fuerte impacto, ya en un futuro próximo, en el incremento de la eficiencia de los
programas de mejora tradicionales. La presente tesis pretende ampliar el conocimiento actual de
aquellos factores que reducen el crecimiento, la productividad y la calidad de la cebada en
ambientes mediterráneos. Con este fin se ha evaluado en ensayos situados en la provincia de
Lérida (nordeste de España) y, ocasionalmente, en las provincias de Navarra (norte de España)
y Valladolid (centro de España), un conjunto de diez genotipos de cebada (incluyendo dos y seis
carreras) que difieren en adaptación a ambientes semiáridos.
Inicialmente, un conjunto de tres genotipos modernos y altamente productivos
(Barberousse, Orria y Plaisant) fue utilizado para examinar el efecto que una reducción del
sumidero reproductivo (número de granos por espiga) provocaba sobre el peso y el crecimiento
del grano, la acumulación de carbohidratos y el transporte de nitrógeno en condiciones semiáridas
(Capítulos I y II). Los incrementos en peso del grano obtenidos en respuesta a una reducción del
sumidero del 50% fueron progresivamente superiores en aquellos ambientes con granos testigo
de menor peso. Por el contrario, el nitrógeno se acumuló uniformemente en todos los ambientes
en respuesta a una reducción del sumidero. Estos resultados sugieren que el rendimiento final se
encuentra fuertemente limitado, en ambientes productivamente pobres, por la disponibilidad de
carbohidratos durante el llenado del grano, mientras que la acumulación de proteínas en el grano
parece independiente de las condiciones ambientales en las que el llenado del grano tiene lugar.
El grado de limitación ejercido por la fuente fue más elevado para los granos situados en
espiguillas laterales de la espiga, con independencia de la disponibilidad de asimilados durante
el llenado del grano. Esta desventaja de los granos laterales de la espiga pudo atribuirse
principalmente a tasas inferiores de acumulación de materia seca durante el llenado.
La influencia de estreses abióticos tales como la sequía o las altas temperaturas en el
proceso de llenado de los granos se examinó en detalle utilizando el conjunto de los diez
genotipos ensayados en doce ambientes (Capítulos III y IV). El objetivo final perseguido
consistió en detectar variabilidad genética así como en determinar posibles mecanismos
morfofisiológicos de tolerancia a dichos estreses. Los posibles factores causantes de interacción
genotipo-ambiente (G*E) en el peso del grano, la tasa y la duraoión de llenado se estudiaron
mediante el uso de modelos estadísticos biaditivos. Se detectaron sensibilidades genotípicas
diferenciales en la tolerancia a la sequía y a las elevadas temperaturas de post-antesis para el peso
final del grano, que se atribuyeron parcialmente a diferencias entre los grupos de cebadas de dos
y seis carreras. La presencia de G*E para la tasa de llenado se explicó por el efecto conjunto de
variables climáticas de pre-antesis, lo que sugirió que las diferencias genotípicas pudieran deberse
parcialmente a diferencias en el balance fuente/sumidero entre cebadas de dos y seis carreras en
antesis. La existencia de G*E para la duración del llenado pudo atribuirse principalmente a
diferencias en fecha de antesis entre genotipos, indicando la existencia de cierta estrategia de
escape causante de un alargamiento del periodo de llenado de algunos genotipos al final del ciclo
de cultivo.
La relación entre rendimiento y discriminación isotópica del carbono (A) en granos se
evaluó extensamente en un grupo de 22 ambientes (Capítulo V), y también se examinó la
posibilidad de utilizar la concentración de cenizas en tejidos aéreos como substituto de A
(Capítulo VI). La expresión genotipica del rendimiento fue condicionada por el ambiente de una
forma más acusada que la de A. La existencia de GXE para el rendimiento sugirió la presencia
de una interacción cualitativa cuyo punto de cruce cabría situarlo aproximadamente en
productividades medias inferiores a 3 t ha"1. Por el contrario, la clasificación de genotipos para
A no cambió substancialmente con el ambiente. En general, aquellos genotipos con bajos valores
de A y, por tanto, con elevadas eficiencias de transpiración, fueron superiores en ambientes poco
productivos (ambientes por debajo de 3 t ha"1), mientras que valores genotípicos de A elevados
se revelaron como ventajosos en ambientes de rendimientos medios y altos. Es probable que,
cuando la sequía es moderada, un importante sumidero reproductivo, típico de cultivares
modernos, fuerce la planta a incrementar su conductancia estomática y, en consecuencia, el agua
total utilizada. Este fenómeno probablemente invierte la relación negativa esperada entre A y
biomasa o rendimiento cuando la disponibilidad de agua es un factor limitante. Por otra parte,
XVll
la concentración mineral en granos estuvo relacionada frecuentemente y de forma negativa con
A, mientras que no se encontró relación entre la concentración mineral en paja y A. Estos
resultados sugieren que la acumulación mineral en tejidos aéreos muestreados al final del ciclo
de cultivo es independiente de la eficiencia de transpiración durante el llenado del grano. La
concentración de cenizas en granos podría utilizarse como criterio de selección complementario
a A en ambientes semiáridos, si bien es necesario un conocimiento fisiológico más profundo de
los mecanismos que afectan a la acumulación de minerales en el grano.
La sequía representa el principal factor limitante del crecimiento y la productividad de la
cebada en los secanos semiáridos mediterráneos. En el presente estudio, las diferencias en
productividad en un conjunto de 22 ambientes pudieron atribuirse en gran medida a diferencias
paralelas en disponibilidad hídrica desde siembra hasta antesis, período en el cual se determina
el número de granos por m2. La presencia de una interacción G*E de tipo cualitativo para el
rendimiento, así como las relaciones fluctuantes entre rendimiento y A, dependiendo de la
intensidad del estrés hídrico, sugieren que la tolerancia a la sequía y el elevado potencial de
rendimiento son conceptos antagónicos en cebada.
Barley (Hordeum vulgäre L.) is an important temperate cereal extensively cultivated in
Mediterranean climates. It can be grown successfully where the average annual rainfall exceeds
250 mm. Yield improvement for Mediterranean areas during the last decades has been slow
probably due to the limitation that drought and other abiotic stresses exert on plant growth. Future
increases in productivity may be accelerated by a better understanding of processes that control
growth and development and limit genotypic performance of barley provided water is scarce.
Thus, physiological research should have a considerable impact in the near future in increasing
the efficiency of traditional breeding programs. This thesis focusses on widening current
physiological knowledge of factors that curtail growth, productivity and quality of barley in
Mediterranean environments. To that end, a set often genetically diverse barley cultivare, which
includes two- and six-rowed types differing in adaptation to semiarid environments, has been
extensively evaluated in rainfed environments located in the province of Lleida (Northeastern
Spain) and, occasionally, in the provinces of Navarra (Northern Spain) and Valladolid (Central
Spain).
A subgroup of three high yielding, modern six-rowed genotypes (Barberousse, Orria and
Plaisant) was used initially to examine the effect of a decrease in the reproductive sink (i.e.,
number of grains per spike) on individual grain weight and growth, carbohydrate accumulation
and N uptake under semiarid conditions (Chapters I and II). Grain weight increases in response
to a 50% sink-reduction were progressively greater in environments with smaller control grains.
On the contrary, N accumulated uniformly across environments in response to sink manipulation.
These results suggest that grain yield is largely limited by carbohydrate supply (i.e., source
limited) during grain filling in poor rainfed environments, whereas protein accumulation into
growing grains seems independent of the environmental conditions in which grain filling
develops. The degree of such limitation to grain growth was consistently higher for those grains
placed in lateral spikelets of the barley ear, irrespective of the availability of assimilates for grain
filling. Such disadvantage of lateral grains could be ascribed mainly to lower dry matter
accumulation rates during grain filling.
The influence of abiotic stresses such as drought or high temperature in the context of the
grain filling process was further examined for the complete set often genotypes grown in 12
environments (Chapters III and IV). The final objective was to detect genetic variability and to
determine possible morphophysiological mechanisms for tolerance to these abiotic constraints.
Possible factors underlying genotype by environment interaction (GxE) for individual grain
weight (IGW), grain filling rate (GFR) and grain filling duration (GFD) were explored by means
of biadditive models. Differential genotypic sensitivities for IGW were found with respect to
post-anthesis drought and elevated temperatures, which could be partially attributed to the
difference between two- and six-rowed barleys. GXE for GFR could be partially explained by the
joint effect of pre-anthesis climatic variables, suggesting that variation in genotypic behaviour
for this trait may be caused by differences in source/sink balance between two- and six-rowed
genotypes at anthesis. In addition, GXE for GFD seemed to be driven mainly by differences in
anthesis date among genotypes, indicating the existence of an escape strategy lengthening the
grain filling period of selected culti vare at the end of the crop cycle.
The relationship between grain yield and carbon isotope discrimination (A) of mature
grains was thoroughly evaluated in a large set of 22 environments (Chapter V), and the feasibility
of using ash concentration in aboveground tissues as a surrogate of A explored (Chapter VI). The
genotypic expression for grain yield was considerably more affected by the environment than that
for A. GXE for grain yield suggested the existence of a crossover point at below 31 ha"1, whereas
genotypic ranking for A did not changed substantially across environments. Overall, genotypes
with lower A and, thus, with higher transpiration efficiency (TE), performed better in lowyielding
environments, i.e., those below the crossover point, while a high genotypic A was
advantageous in medium and high-yielding environments. It may be possible that, under
moderate drought, a large reproductive sink (typical of modern cultivars) force the plant to
increase its stomatal conductance and, consequently, its total water use. This phenomenon
probably overrides the expected negative relation between A and biomass or yield when water
is limiting. On the other hand, mineral concentration in mature grains was often negatively related
to A, and mineral accumulation in vegetative tissues was unrelated to A. Both results suggest that
mineral accumulation in aboveground tissues, sampled at maturity, is independent of the plant
TE during grain filling. Ash concentration in mature grains could be used as a complementary
criterion to A in semiarid environments, though a more accurate physiological understanding of
the mechanisms underlying mineral accumulation in grains is still needed.
Drought arises as the most limiting factor to barley growth and productivity in rainfed
Mediterranean environments. In the present study, differences in productivity in a set of 22
environments could be attributed largely to concomitant differences in water availability for
growth from sowing to anthesis, a period in which the number of grains m"2 is determined.
Presence of a crossover G*E interaction for grain yield, as well as changing relationships between
productivity and A depending on the intensity of water stress, suggest that drought tolerance and
yield potential are rather antagonistic concepts in barley.
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39

Roux, Evette. "Near infrared (NIR) spectroscopy for selection of malting barley in South African breeding programmes." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6871.

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40

Griffiths, Simon. "Cloning and characterisation of barley homologues of the Arabidopsis CONSTANS gene." Thesis, University of East Anglia, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302058.

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41

Smith, Oliver. "Small RNA-mediated regulation, adaptation and stress response in barley archaeogenome." Thesis, University of Warwick, 2012. http://wrap.warwick.ac.uk/57032/.

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Small RNA are short, 18-25 nt molecules that regulate gene expression in plants and animals. Two main types, microRNA (miRNA) and short interfering RNA (siRNA) perform this regulation by transcript silencing, translation inhibition, DNA methylation and chromatin remodeling. This thesis is an investigation into small RNA activity in archaeological plant material, specifically barley grain from Qasr Ibrim, a multi-period archaeological site in southern Egypt. It is of particular interest due to its unusual phenotype, suggestive of stunted development that is unexpected in a staple, domesticated cultivar, and the unusual level of DNA and RNA preservation attributable to the extremely arid climate at the site. The research presented here is a comparative analysis of small RNA profiles and epigenetic states of Qasr Ibrim barley and modern, unstressed counterparts. It concludes that differential microRNA and epigenetic profiles are the result of stress response, adaptation, dormancy and / or viral infection unique to the archaeological grain. The primary method of investigation was generation of small RNA sequence data using the Illumina GAIIx platform. This was followed by extensive bioinformatic analysis (RNA diagenesis patterns, miRNA prediction, siRNA target prediction and small genome in silico reconstruction) the results of which were in turn validated experimentally (genomic methylation states, locus-specific methylation analysis and direct miRNA detection). The research represents a twofold contribution to knowledge: first, proof-of-principle that biologically meaningful archaeological RNA can be extracted despite its relative instability to DNA, and second that a unique miRNA profile and epigenetic state is detectable in this particular cultivar of archaeological barley.
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42

Shams-Bakhsh, Masoud. "Studies on the structure and gene expression of barley yellow dwarf virus." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phs5275.pdf.

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Bibliography: leaves 118-132. This thesis examines the structure and gene expression of barley yellow dwarf viruses (BYDVs)-PAV in order to gain a better understanding of the interaction between the virus and the Yd2 resistance gene. The protein products of open reading frame (ORF)3, ORF4 and ORF5 are expressed in bacterial cells, in order to characterise the BYDV-PAV virion-associated proteins. The effect of the Yd2 resistance gene on the expression of the BYDV-PAV viral proteins in infected cells is also studied.
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43

El-Zayadi, Fawzi. "A genetic analysis of harvest index in barley (Hordeum vulgare L. emend. Lam.) /." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65362.

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44

Sheedy, Michael David 1959. "GENETIC COMPOSITION OF THE TWO INTERDEPENDENT FRAGMENT CHROMOSOME PAIRS IN AN 8II BARLEY (HORDEUM VULGARE L.) (TRISOMIC ANALYSIS, COMPENSATING DIPLOID)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/275553.

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45

Eckhoff, Joyce Lynne Alwine. "EVALUATION OF THE MALE-STERILE CYTOPLASM, MSM1, FOR USE IN HYBRID BARLEY SEED PRODUCTION (HORDEUM)." Diss., The University of Arizona, 1985. http://hdl.handle.net/10150/282087.

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Possible maintainer lines were selected from CC XXXII and crossed onto cytoplasmically male-sterile plants. Complete male sterility was maintained in both the F₁ and BC₁ generations of 46.4% of the lines. Four cultivars with maintainer genotypes that were in both normal and msm1 cytoplasm were intercrossed using the male-sterile forms as the female parents. All F₁'s were completely male-sterile. Restoration of male fertility by 22 lines selected from CC XXXII was shown in each case to be due to a single dominant gene. In some lines, restoration was influenced by environment and genetic background. Partial restoration was observed in cultivars in the World Collection and lines selected from CC XXXII. Partial restoration appeared to be due to several genes that were subject to environmental influence. Accumulation of some of these genes increased the amount of restoration. There was no evidence that cytoplasmic factors were passed through the pollen. Twenty-two F₁ hybrids were produced by crossing restorer lines onto male-sterile msm1 lines. The 22 hybrids, their 44 parental restorer and maintainer lines and six check cultivars were grown in a four-replication yield trial. Total yield, 1000-seed weight and hectaliter weight were measured for each plot. All the F₁ hybrids outyielded their midparent values and 17 of the hybrids outyielded their high parents. Half of the F₁'s outyielded the high check cultivar, which yielded about 9,130 kg/ha. Twenty-one F₁'s had greater 1000-seed weights than their midparent values while only 11 F₁'s had greater 1000-seed weights than their high parents. The high check cultivar had the greatest 1000-seed weight, 49.0 gm. The hybrids with the greatest 1000-seed weights were not the hybrids with the greatest yields. Eighteen of the F₁'s had greater hectaliter weights than the midparent values, but only seven had greater hectaliter weights than their high parents. The high check cultivar had the greatest hectaliter weight, 75 kg. The hybrids with the greatest hectaliter weights were not the highest yielding hybrids.
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46

Rathjen, John Paul. "Aspects of luteovirus molecular biology in relation to the interaction between BYDV-PAV and the Yd2 resistance gene of barley /." Title page, contents and summary only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phr2342.pdf.

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47

Wilson, Christine M. "Molecular and cellular studies of early endosperm development in barley (Hordeum vulgare L.)." Thesis, Durham University, 1997. http://etheses.dur.ac.uk/5099/.

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Barley grain is an important commercial crop, being used mainly as an animal feed and in the production of malt for the brewing and distilling industries. The protein and carbohydrate composition of the endosperm (the major storage tissue) determines the grain quality and suitability for different end uses. The differentiation and maturation stages of endosperm development have been extensively studied. However, little is known about the cellular and molecular biology of the syncytial and cellularisation stages of development which occur within the first 8 days post anthesis (DPA). Events occurring during this period of development are particularly important as the overall pattern for the development and structure of the grain is laid down. Patterns of gene expression during the syncytial and cellularisation stages were investigated. A cDNA library was constructed from whole caryopses aged between 1 and 10 DPA. This cDNA library was then differentially screened using mRNA from 3 and 10 DPA caryopses. Northern and dot blot analysis led to the isolation of a number of clones which appear to show variation in level of expression. Partial sequencing of some of these clones and FASTA analysis (Genetics Computer Group, 1991) has shown four clones to have significant identity to sequences in the databases. These clones were clone 27B which showed identity to Ketol acid reductoisomerase (KARI) sequences, clone 16D which showed identity to Caffeoyl CoA-O-methyltransferase (CCoAOMT) sequences, clone 3B which showed identity to sucrose synthase sequences and clone 16B which showed identity to blue copper-binding protein sequences. A further 4 clones which were sequenced showed no significant identity to data base entries following FASTA analysis (Genetics Computer Group, 1991). The temporal and spatial distribution of these clones within tissues of barley caryopses was then analysed by in-situ hybrdisation. None were found to be associated uniquely with the endosperm tissues of barley caryopses. However, there were indications that the expression of the genes represented by the cDNA clones might vary during the course of development. Immunolocation studies utilising a set of JIM (John Innes Monoclonal) antibodies (and MAC207), which recognise carbohydrate epitopes of arabinogalactan proteins (AGP) were also carried out. AGPs have been associated with the plant cell surface and have been ascribed a number of possible functions related to developmental processes. The temporal and spatial distribution of AGPs within barley endosperm was analysed using sections from fixed and embedded barley caryopses and immunolocalisation techniques at the light microscope level. This revealed that at least one AGP epitope, recognised by JIM13, was expressed during early barley grain formation. JIM 13 binding was observed in developing barley caryopses at the beginning of endosperm cellularisation. It was localised to the first anticlinal and then periclinal endosperm cell walls, to the crease region and the nucellar/endosperm boundary. It was not observed in any caryopsis tissue at the earlier stage of syncytial endosperm and unfortunately its distribution could not be studied at later stages of endosperm development because of poor structural integrity within the sections.
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48

Norberg, Amanda. "Differences in nutrient content between varieties of Nordic barley." Thesis, Linköpings universitet, Biologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-138604.

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Grain protein content (GPC) in wheat has been found to be regulated by the gene NAM-B1. Homologues to the NAM-B1 gene have been found in barley, HvNAM-1 and HvNAM-2. Previous studies have found that base mutations in the NAM-1 gene at base position 544 might have an impact on GPC. Previous studies also found that landrace of barley showed higher GPC than cultivated barley, indicating that plant improvement might have affected base mutations and therefore GPC. I wanted to study if there are any nutritional differences in Nordic barley and if those differences might correlate with haplotypes. Comparisons of barley varieties from four Nordic countries, and two varieties from the US used as low and high GPC controls, did not show any significant differences depending on their origin country and no differences regarding plant improvement status between the countries. When sequencing Nordic barley varieties, five haplotypes were found for the gene HvNAM-1, and two haplotypes for the gene HvNAM-2. A low polymorphism for both genes indicate a strong natural selection for the consensus haplotype which might be preferable for Nordic climate with a short growing season and cold temperatures. Even though it is not clear what is the cause of the low polymorphism in Nordic barley varieties, they showed a generally higher nutrient content than barley varieties of the high GPC and may be suitable for breeding for a yield with a high nutrient content.
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49

Ranford, Julia Claire. "Studies on the expression of dormancy-related genes in barley (Hordeum vulgare L.)." Thesis, Heriot-Watt University, 1999. http://hdl.handle.net/10399/602.

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50

Clark, Dale Rogers. "Methods of screening for induced apomictic mutants in barley (Hordeum vulgare L.)." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184354.

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Plants that are heterozygous for genetic markers but do not produce segregating progeny may be suspected of carrying a mutation conditioning apomixis. Seed stocks in which heterozygous plants could be identified phenotypically were treated with a chemical mutagen. These seed stocks were heterozygous for recessive genetic markers, and/or heterozygous for a chromosome translocation. Spikes from heterozygous M1 plants were harvested and seeded in bulk. Spikes from heterozygous M2 plants were harvested and planted in M3 rows. The M3 rows were observed for the absence of segregating progeny and/or were observed cytologically for the presence of a heterozygous translocation. M3 rows not segregating for the genetic markers were crossed onto plants homozygous for the genetic markers. The F1 progenies were observed for an expected ratio of 1 normal: 1 recessive plant. All nonsegregating lines were found to be non-heterozygous. These lines most likely occurred due to seed and pollen contamination or were the result of crossing over between genetic markers. Fertile M2 plants were harvested from the treated heterozygous translocation seed stock. Normally, barley plants heterozygous for a translocation will produce semisterile spikes. Plants that would normally be semisterile but are fertile could be carrying a mutation conditioning apomixis. Progeny of the fertile M2 plants were examined cytologically for the presence of the heterozygous translocation. All selected lines contained the normal seven pairs of chromosomes and were the result of seed or pollen contamination. Seed stocks which could eliminate the problem of contamination in future experiments were developed and discussed. Haploviable mutants closely linked with the male sterile locus, msg2, were isolated in these seed stocks. Haploviable mutants are recognized by upset genetic ratios of alleles linked with the mutant. Selfed progenies of plants carrying a haploviable mutation contained fertile and male sterile plants in about a 1:1 ratio. Mostly male sterile progenies were obtained when plants heterozygous for the haploviable mutant and the male sterile allele were crossed onto male sterile plants. Four lines containing haploviable mutants were evaluated for their usefulness in producing all male sterile lines for hybrid barley production.
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