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Dissertations / Theses on the topic 'Plant genetics'

Author: Grafiati

Published: 4 June 2021

Last updated: 30 July 2024

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1

McCue, Kimberlie A. "The ecological genetics of rarity : a study of genetic structure, inbreeding and seed bank dynamics in a rare annual plant /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841324.

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2

Kirst, Matias. "TRANSCRIPTION REGULATION AND PLANT DIVERSITY." NCSU, 2004. http://www.lib.ncsu.edu/theses/available/etd-01042004-175350/.

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Transcript abundance measured for any gene on a microarray can be considered as a quantitative trait. If the transcription profile of a sufficient number of individuals from a segregating progeny is generated by microarrays, it allows mapping of genomic regions regulating variation in transcript abundance using traditional methods of QTL analysis. We generated transcript level profiles of wood forming tissue (differentiating xylem) collected from 91 individuals from a E. grandis x E. globulus F1 hybrid x E. grandis backcross population, using microarrays containing 2608 cDNAs. Least-square means estimates of transcript abundance were generated for each individual and cDNA, and mapped as QTLs in two single-tree linkage maps (hybrid paternal and E. grandis maternal) using composite interval mapping. QTLs were identified for 811 genes in the Eucalyptus hybrid map, displaying in most cases a simple genetic architecture, with a single QTL controlling up to 70% of the transcript level variation. A more complex genetic architecture was detected in one third of the genes, where up to five QTLs could be identified for three genes. QTL hotspots were identified in both maps, typically for genes encoding several enzymes of specific metabolic pathways, suggesting coordinated genetic regulation. Transcript level QTLs were co-localized to QTLs detected previously in this family for wood quality and growth traits and candidate genes were identified by the analysis of correlation between gene expression and phenotypic variation.

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3

DeCarme, Ashley R. "Searching for the Seed Plant Ethylene Pathway in a Basal Plant Lineage: A Genomic Approach." W&M ScholarWorks, 2011. https://scholarworks.wm.edu/etd/1539626914.

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4

Singh, Nagendra Kumar. "The structure and genetic control of endosperm proteins in wheat and rye." Title page, contents and abstract only, 1985. http://web4.library.adelaide.edu.au/theses/09PH/09phs6174.pdf.

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5

Baldwin, Samantha, and n/a. "Models for genetic analysis of polyploid plant species." University of Otago. Department of Biochemistry, 2008. http://adt.otago.ac.nz./public/adt-NZDU20090826.092431.

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A number of major crop species, such as allohexaploid wheat and autotetraploid potato are polyploid. Potato is the fourth most important crop in terms of production and has become an important food source in many countries. Therefore, the molecular analysis was directed towards investigating ways to develop markers to assist the potato breeding process; for example breeding for powdery scab disease resistance, and tolerance to cold induced sweetening. Polyploids have more possible genotypes per population, allele dosage effects and increased marker complexity compared to diploids. Potato is also outcrossing and therefore highly heterozygous. Various methods for detecting marker-trait associations including, linkage, quantitative trait locus (QTL) and association mapping were studied and protocols developed. A mapping population was produced and a number of traits were measured including powdery scab resistance. Powdery scab disease assays were carried out over six seasons and markers associated with disease resistance were identified. Markers associated with resistance to powdery scab were identified on chromosomes I, IV, V, VI, VIII and IX using analysis of variance (ANOVA). Linkage maps were produced for each parent of the population and QTL associated with resistance and susceptibility to disease were identified using interval mapping, which revealed QTL on chromosomes II, V, VII , VIII, IX and an unanchored linkage group. QTL were detected across years on regions of chromosomes VIII and IX. These QTL results had some overlap with the marker-trait associations that were identified using ANOVA analysis. Another marker identification technique was tested, known as association or linkage disequilibrium mapping. Alleles of candidate genes were tested for association with cold-induced sweetening using a germplasm collection. The alleles identified as important were of the apoplastic invertase and UGPase genes and a unique interaction between alleles of the apoplastic invertase and apoplastic invertase inhibitor was also detected. This thesis describes the first study into the genetics of powdery scab resistance and the markers identified as associated with resistance will be validated for use in a marker-assisted selection (MAS) programme. The tools and resources developed as part of this thesis are vital to the potato breeding programme that requires the identification of associated molecular markers.

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6

Sachan, Nita. "Identification of signaling factors involved in the regulation of alkaloid metabolism in N.tabacum." Lexington, Ky. : [University of Kentucky Libraries], 2004. http://lib.uky.edu/ETD/ukyplph2004d00179/NS%5FDiss.pdf.

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Thesis (Ph. D.)--University of Kentucky, 2004.
Title from document title page (viewed Jan. 7, 2005). Document formatted into pages; contains x, 127p. : ill. Includes abstract and vita. Includes bibliographical references (p. 118-126).

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7

Boyko, Oleksandr, and University of Lethbridge Faculty of Arts and Science. "Influence of various factors on plant homologuous recombination." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2004, 2004. http://hdl.handle.net/10133/243.

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The genome of living organisms is constantly subjected to the environmental influences that result in different negative, negligible or positive impacts. The ability to maintain the genome integrity and simultaneously provide its flexibility is the main determinant for the evolutionary success of any species. One of the important aspects of genome maintenance is the precise regulation of the DNA repair machinery. Results reported here indicate the existence of a tight, age-dependent regulation of homologous recombination, one of the two main DNA double-strand break repair pathways. We show that recombination is influenced by conditions such as the change of temperature (cold or warm), day length, water availability (drought or overwatering stress) and salinity. These stresses not only influence the genome stability of stress-subjected generations but also change the recombination in subsequent generations. This indicates the possible involvement of homologous recombination in plant evolution and development of plant stress tolerance.
xiv, 121 leaves ; 29 cm.

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8

Luijten, Sheila Helen. "Reproduction and genetics of fragmented plant populations." Amsterdam : Amsterdam : Instituut voor Biodiversiteit en Ecosysteemdynamica (IBED) ; Universiteit van Amsterdam [Host], 2001. http://dare.uva.nl/document/60623.

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9

Filkowski, Jody, and University of Lethbridge Faculty of Arts and Science. "The effect of pathogens on plant genome stability." Thesis, Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences, 2004, 2004. http://hdl.handle.net/10133/254.

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Resistance (R) genes, a key factor in determining the resistance of plants, have been shown often to be highly allelic entities existing in duplicated regions of the genome. This characteristic suggests that R-gene acquisition may have arisen through frequent genetic rearrangements as a result of transient, reduced genome stability. Tabacco plants transgenic for a recombination construct exhibited reduced genome stability upon infection with a virulent pathogen (tobacco mosaic virus). The reduced genome stability manifested as an increase in recombination events in the transgene. Such increases were observed following a virulent pathogen attack. This increase in recombination was shown to be systemic and was observed prior to systemic viral movement suggesting the presence of a systemic recombination signal. Further molecular analyses revealed that specific R-gene loci experience a large frequency of rearrangements following a virulent pathogen encounter. The possible targeting of instability to R-gene regions may be controlled through epigenetic processes, in particular, DNA methylation.
xiii, 119 leaves ; 29 cm.

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10

Kingham, Keith Iain. "Nuclear differentiation in plant development." Thesis, Queen Mary, University of London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300588.

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11

Bitalo, Daphne Nyachaki. "Implementation of molecular markers for triticale cultivar identification and marker-assisted selection." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71670.

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Thesis (MSc)--Stellenbosch University, 2012.
Triticale is an amphidiploid that consists of wheat (A and B) and rye (R) genomes. This cereal is fast becoming important on a commercial basis and warrants further assessment for the better management and breeding of the hybrid. The assessment of the genetic diversity among the wheat and rye genomes within triticale can be obtained by using molecular markers developed in both donor genomes. Simple sequence repeats markers (SSRs) and amplified fragment length markers (AFLPs) have been previously used to assess the genetic diversity among triticale lines. SSRs are highly polymorphic markers that are abundant and which have been shown to be highly transferable between species in previous studies while AFLP markers are known to generate plenty of data as they cover so many loci. Thus, the aim of this study was to develop a marker system suitable to assess the genetic diversity and relationships of advanced breeding material (and cultivars) of the Stellenbosch University’s Plant Breeding Laboratory (SU-PBL). Therefore, both AFLP and SSR markers were initially analysed using eight triticale cultivars (with known pedigrees) to facilitate cultivar identification. Fourty-two AFLP primer combinations and 86 SSR markers were used to assess the genetic diversity among the Elite triticale cultivars. The AFLP primer combinations generated under average polymorphism information content (PIC) values. Furthermore, these markers generated neighbour-joining (NJ) and unweighted pair group method with arithmetic average (UPGMA) dendograms that displayed relationships that did not correspond with the available pedigree information. Therefore, this marker system was found not to be suitable. A set of 86 SSRs previously identified in both wheat and rye, was used to test the genetic diversity among the eight cultivars. The markers developed in wheat achieved 84% transferability while those developed in rye achieved 79.3% transferability. A subset of SSR markers was able to distinguish the cultivars, and correctly identify them by generating NJ and UPGMA dendograms that exhibited relationships that corroborated the available pedigree data. This panel of markers was therefore chosen as the most suitable for the assessment of the advanced breeding material. The panel of seven SSR markers was optimised for semi-automated analysis and was used to screen and detect the genetic diversity among 306 triticale entries in the F6, Senior and Elite phases of the SU-PBL triticale breeding programme. An average PIC value of 0.65 was detected and moderate genetic variation was observed. NJ and UPGMA dendograms generated showed no clear groupings. However, the panel of markers managed to accurately identify all cultivars within the breeding program. The marker panel developed in this study is being used to routinely distinguish among the advanced breeding material within the SU-PBL triticale breeding programme and as a tool in molecular-assisted backcross.

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12

Abreu, Aluana Gonçalves de. "Estudo em um fitofago especialista, Tomoplagia reticulata (Diptera:Tephritidae), e sua planta hospedeira, Eremanthus glomerulatus (Asteraceae)." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317346.

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Orientador: Vera Nisaka Solferini
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
Made available in DSpace on 2018-08-13T04:40:21Z (GMT). No. of bitstreams: 1 Abreu_AluanaGoncalvesde_D.pdf: 3682927 bytes, checksum: e8b0e5d165148e225082c7057c66bb6e (MD5) Previous issue date: 2009
Resumo: Tomoplagia reticulata (Diptera: Tephritidae) é um fitófago especialista em Eremanthus glomerulatus (Asteraceae). Os adultos ovipõem nas inflorescências da planta hospedeira, onde as larvas se desenvolvem. O histórico de coletas de T. reticulata mostra uma grande variação na quantidade de insetos infestando cada indivíduo de E. glomerulatus. A fim de verificar se a variação no número de herbívoros nas populações do hospedeiro é associada a alguma característica química e/ou genética deste, comparamos as variabilidades genética e química entre indivíduos de E. glomerulatus com diferentes níveis de infestação por T. reticulata (cap. 1). Eremanthus glomerulatus tem baixa variabilidade genética, provavelmente associada à distribuição restrita desta espécie. Apesar da distribuição fragmentada, há pouca estruturação entre as populações desta planta, explicada pelo maior fluxo gênico entre ambientes fragmentados em espécies anemocóricas. As características genéticas e químicas de E. glomerulatus não explicam a variação no nível de herbivoria das populações do hospedeiro. No capítulo 2, testamos a hipótese de que fitófagos especialistas apresentam maior diferenciação genética e menor diversidade do que generalistas, comparando o nível de variabilidade e estrutura genética de T. reticulata com o de outros fitófagos com diferentes amplitudes de hospedeiro. As populações de T. reticulata apresentaram baixa variabilidade e grande estruturação genética, o que é associado à distribuição fragmentada da planta hospedeira, que restringe a distribuição das pequenas populações do inseto. No capítulo 3, caracterizamos a composição genética das populações de Tomoplagia reticulata e de T. pallens, uma espécie irmã. Ambas as espécies parasitam E. glomerulatus; T. reticulata ocorre em MG e T. pallens em GO. Há uma zona de contato entre as espécies no Sul de MG, onde elas hibridizam. Ocasionalmente T. pallens chega ao centro de MG (Santana do Riacho), região mais fria. Esta migração provavelmente está associada a anos excepcionalmente quentes.
Abstract: Tomoplagia reticulata (Diptera: Tephritidae) is a phytophagous insect which is specialist on Eremanthus glomerulatus (Asteraceae). Adults oviposit in flower heads, where larvae develop. Sampling records for T. reticulata show that there is great variation in the number of insects parasitizing each plant. To verify if this variation is associated with chemical or genetic characteristics of the host plant, we assayed E. glomerulatus' genetic and chemical variability and compared between individuals with different levels of infestation by T. reticulata (chapter 1). Eremanthus glomerulatus has low genetic variability, probably related to its narrow geographic distribution. There is low genetic structure among populations despite its fragmented distribution, due to enhance gene flow in fragmented habitats in anemocoric species. E. glomerulatus' chemical and genetic characteristics don't explain variation in herbivory. In chapter 2, we tested the hypothesis that herbivorous insect species with narrow diet breadth are expected to be more prone to genetic differentiation and lower genetic diversity than insect species with a wider diet breadth, comparing T. reticulata's genetic variability and structure with other phytophagous with different host ranges. Tomoplagia reticulata has low genetic variability and great genetic structure, which is associated with its host fragmented distribution that restricts the distribution of insect populations. In chapter 3, we described genetic composition of Tomoplagia reticulata and T. pallens, a sister species. Both of them parasitize E. glomerulatus; T. reticulata occurs in MG and T. pallens in GO. There is a contact zone between them in southern MG, where they hybridize. Occasionally, T. pallens arrives in the center of MG (Santana do Riacho), a colder region. This migration is probably associated with extremely hot years.
Doutorado
Genetica Animal e Evolução
Doutor em Genetica e Biologia Molecular

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13

Howis, Seranne. "A taxonomic revision of the southern African endemic genus Gazania (Asteraceae) based on morphometric, genetic and phylogeographic data." Thesis, Rhodes University, 2007. http://eprints.ru.ac.za/1716/.

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14

Holding, David Richard. "Analysis of the regulation and function of the pale cress gene of Arabidopsis thaliana." Thesis, King's College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267878.

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15

Lim, Saw Hoon. "Molecular analysis of porphobilinogen deaminase in higher plants." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259764.

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16

Wong, Kwong-chiu Alfred. "Conservation genetics of Hong Kong wild orchids /." Hong Kong : University of Hong Kong, 1998. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2035793X.

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17

Yaish, Sami Abdul-Rahman. "Construction and screening of plant genomic libraries." Thesis, Durham University, 1990. http://etheses.dur.ac.uk/6054/.

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A library of pea (Pisum sativum L) genomic DNA in bacteriophage EMBL3 was screened for seed storage protein genes of the legumin and vicilin families. Three genomic clones were isolated. One of the clones was found to contain a gene in the Leg A sub-family which was designated Leg E. The nucleotide and predicted amino acid sequence of Leg E were compared to those of Leg A. The coding sequences of both genes are strongly homologous with only 9 bases difference out of 1560 bases. A second genomic clone contained two genes from the Leg J subfamily. Leg J and Leg K. The clone was shown to overlap with a genomic clone isolated previously, JC5 (Gatehouse et al. 1988). Strong homology was found between the Leg K and Leg J sequences. The Leg K gene is predicted to be pseudogene, due to the conversion of the ATG methionine start codon to a GTG valine codon and the presence of a stop codon in the 5' end of the coding sequence in the reading frame predicted by the first subsequent start codon. A genomic library was constructed for Arabidopsis thaliana, using EMBL3 as a vector to sub-clone Sau3AI partially digested Arabidopsis genomic DNA. About 8 x 10(^4) random clones were obtained when the ligated vector DNA and insert were in vitro packaged. The Arabidopsis gene library was screened for clones containing sequences encoding the cell wall protein extensin, using a rape (Brassica napus L extensin cDNA as a probe. Six clones were isolated, two of which were restriction mapped. One of them was partially sequenced. This clone did not contain an extensin gene homologous to the probe sequence, and only contained a short extensin-like sequence which was responsible for the observed hybridisation. The putative gene may represent another type of protein, since it was expressed in the root of Arabidopsis and Brassica napus L, as shown by "Northern" blots which were probed with labelled DNA from the clone.

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18

Ng, Sai-chit. "Hong Kong's rhododendrons : ecology, population genetics and conservation /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21482743.

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19

Phelan, Thomas Joseph. "GENETIC AND MOLECULAR ANALYSIS OF PLANT NUCLEAR MATRIX PROTEINS." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20011104-233111.

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PHELAN, THOMAS JOSEPH, Genetic and Molecular Analysis of Plant Nuclear Matrix Proteins. (Under the direction of Steven L. Spiker.)The eukaryotic nucleus is composed of DNA, RNA and protein, encapsulated by a nuclear envelope. DNA is compacted up to ten thousand times in order to be packaged into the nucleus. The nucleus must maintain order in the presence of a very high density and variety of protein and RNA. The nuclear matrix is a proteinaceous network thought to provide structure and organization to the nucleus. We believe that relatively stable interactions of nuclear molecules with the nuclear matrix are key to organization of the nucleus. Numerous "Matrix Attachment Region" DNA elements (MARs), have been isolated from plants, animals, and fungi. Evidence suggests that these MARs attach to the nuclear matrix, delimiting loops of chromosomal DNA. In studies of transgenic plants and animals, MARs have been shown to give important advantages to organisms transformed with genes flanked by these elements. Unlike most DNA elements, no specific sequence elements have been identified in MAR DNAs. Partly due to the insolubility of the matrix, and to the heterogeneity of MAR DNA, very few of the protein components of the nuclear matrix have been identified. This work presents analysis the proteins of the plant nuclear matrix. We have characterized a set of related proteins from the model plant Arabidopsis that associate with MAR DNA in vitro. These proteins appear to be similar to the NOP56/NOP58 family of proteins previously identified in several eukaryotic organisms. The NOP56/NOP58 proteins are thought to be involved in modifications of ribosomal RNA. Binding studies presented in this work suggest that these plant proteins may participate in RNA/DNA/protein complexes in the nucleus.

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20

Vaitkunas, Katrina Emilee. "The genetics of TCV resistance." Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0428103-102720.

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21

Kreivi, M. (Marjut). "Conservation genetics and phylogeography of endangered boreoarctic seashore plant species." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514290190.

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Abstract The amount and distribution of genetic diversity are likely to affect the evolutionary potential of a species. When feasible and cost-effective policies for management and monitoring of endangered populations or species are planned, knowledge of the spatial genetic structure and the type of population dynamics is of great concern. In this thesis the genetic diversity and population structures of two endangered arctic plant species was examined on different geographical scales in Northern Europe. The species were Siberian primrose (Primula nutans) and pendant grass (Arctophila fulva), which both grow in a seashore habitat and have similar distribution patterns on the shores of the Arctic Ocean and the Bothnian Bay. The goal of the present study was to provide basic population genetic information for the study species using microsatellite and AFLP markers. Both markers were used for the first time in these species, and species-specific microsatellite markers were developed during the study. A further aim was to interlink the population genetic processes of the species into distribution patterns at the regional and population levels and to compile a synthesis of the impact of hierarchical spatiotemporal processes and autocorrelation in genetic variation at different levels. The studies of this thesis provided new information on the diversity and population structure of the endangered study species and new markers that are useful in future genetic studies of primrose species. The diversity of Siberian primrose was low, and there was no dispersal between the study regions. In pendant grass, a relatively high amount of variation was found considering the evident clonal reproduction and gene flow that was detected between populations connected by waterways. The results suggested that both clonal and sexual reproduction are important in this species. On a local scale, pendant grass populations had characteristics of “stepping stone” and classical metapopulation models. The results indicated that on a long time scale, both species will continue to decline without efficient management efforts. Most critical for the persistence of the species is the conservation of suitable habitats. Translocations could be considered in order to enhance the diversity of existing populations and establish new populations. By examining the present day structure of Siberian primrose, it was possible to make inferences regarding the colonisation history of the species in the North European area. The current distribution of Siberian primrose seemed to result from a vicariant process that took place after the last ice-age, when the species colonised the area. It spread first to the White Sea area, probably from the east, and subsequently colonised the Bothnian Bay and the Barents Sea in the west. The isostatic land uplift after the retreat of the Eurasian ice sheet uncovered large areas of land from the Baltic Sea basin that previously were under water. These geological changes resulted in the current disjunct distribution of Siberian primrose.

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22

Hammouri, Mahmoud Khalil. "The investigation of plant cells using vibrational microspectroscopy." Thesis, University of East Anglia, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294066.

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23

Biggs, Karen. "Tyrosine cross-links in plant cell wall glycoprotein." Thesis, University of Edinburgh, 1988. http://hdl.handle.net/1842/10809.

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24

Winterer, Juliette. "The ecology and evolution of plant defense, herbivore tolerance, and disease virulence /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/5241.

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25

Chaulk, Christine Annie 1964. "Chromosome number, fertility, and mitochondrial genome of backcross populations derived from Medicago sativa x Medicago dzhawakhetica hybrids." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277157.

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Backcross populations (BC) from Medicago sativa L. x M. dzhawakhetica Bordz. hybrids were analyzed for chromosome number, fertility and morphological characteristics. Previously obtained F1 hybrids were recovered when diploid (2n = 2x = 16) M. sativa was crossed with tetraploid (2n = 4x = 32) M. dzhawakhetica. Resulting F1 hybrids were triploid (2n = 3x = 24), completely male sterile and had low levels of female fertility. Subsequent populations were obtained by successive backcrossing to unrelated (4x) M. sativa clones. The BC1 plants were pentaploid (2n = 5x = 40) and both male and female fertile. BC2 populations had chromosome numbers ranging from 2n = 32 to 48, and most plants (94% were male and female fertile. BC3 populations were tetraploid (2n = 32) or near tetraploid (2n = 33) and were morphologically similar to M. sativa. Preliminary analysis of mitochondrial nucleic acids by agarose gel electrophoresis, indicated biparental inheritance of this organelle in the F1 hybrids; however, further analysis provided inconclusive results.

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26

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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27

Wang, Tsung-Tsan 1959. "Transformant system and gene expression of yeast Schwanniomyces occidentalis." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=35955.

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Schwanniomyces occidentalis (Debaryomyces occidentalis ) is able to grow rapidly with high cell mass on cheap starch as a carbon source, produce strong amylolytic enzymes extracellularly and secrete large proteins without hyper-glycosylation and measurable extracellular proteases. Schw. occidentalis thus has a high potential as, a useful alternative to Saccharomyces cerevisiae in the production of heterologous proteins. However, the molecular study of Schw. occidentalis has been very limited due to the insufficient transformation system and lack of gene expression information.
A new transformation system of Schw. occidentalis has been developed. This system was based on vector YEp13 ( LEU2) and a stable leu auxotrophic mutant, Schw. occidentalis DW88, obtained by treating the yeast with 1-methyl-3-nitro-1-nitrosoguanidine. The transformation efficiency of YEp13 by spheroplast-mediating method was 103 transformants/mug DNA. The 2-mum replicon is proposed to be responsible for YEp13 replication in Schw. occidentalis. The YEp13 stability in Schw. occidentalis was low, but it kept its structure in the yeast, suggesting that Schw. occidentalis DW88 does not modify foreign DNA.
After analysis of 14 cloned Schw. occidentalis genes and comparison of associated genes from both Schw. occidentalis and S. cerevisiae, 25 codons were arbitrarily chosen as putative preferred codons for Schw. occidentalis. They are similar to those of S. cerevisiae, except for TTA for leucine, and AAA for lysine. Codon Bias Index (CBI), a criterion to evaluate gene expression, is calculated from preferred codons. A computer program (PCBI) which reads a gene containing introns was developed to quickly calculate CBI.
Schw. occidentalis DWSS should be a good host to produce and secrete heterologous proteins and the putative preferred codons and program PCBI can facilitate molecular study of Schw. occidentalis. (Abstract shortened by UMI.)

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28

Choe, Sunghwa. "Genetics and biology of Arabidopsis brassinosteroid dwarf mutants." Diss., The University of Arizona, 1997. http://hdl.handle.net/10150/298758.

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Brassinosteroids (BRs) have long been known to be effective in plant growth promotion. However, definitive evidence of BR's role in growth stimulation has remained unclear. Recently, genetic approaches using BR-deficient dwarf(dwf) mutants have begun to unravel the role of BRs in plant growth and development. BR dwarf mutants are characterized by multiple growth alterations: robust stem, reduced fertility, prolonged life cycle, dark-green appearance, round and curled leaves, and when grown in the dark, short hypocotyls and expanded cotyledons. Genetic analysis of the dwf mutants defined eight independent genetic loci defective in BR biosynthesis or perception. Allelism tests with previously reported genes revealed that d̲i̲m̲inuto 1 (dim1) was an allele of dwf1, and dwf2, dwf3, and dwf6 are allelic to b̲r̲assinosteroid i̲nsensitive (bri), c̲onstitutive p̲hotomorphogenesis and d̲warfism (cpd), and d̲e̲-e̲t̲iolated2 (det2), respectively. dwf4, dwf5, dwf7, and dwf8 were found to be novel and are the focus of this research. Anatomical analysis demonstrates that a reduction in cell length causes dwarf phenotype. Dwarfism was rescued by exogenous application of BRs. Feeding studies utilizing BR biosynthetic intermediates were employed to identify defective steps of BR biosynthesis in each of these dwarf mutants. dwf4 mutants were rescued only by 22α hydroxylated BRs, suggesting that the 22α hydroxylation reactions, putative rate-determining steps, are blocked. In fact, DWF4 has been cloned and shown to encode a cytochrome P450 steroid hydroxylase. Feeding studies also showed that dwf8 plants are rescued only by intermediates after 3 dehydrogenation reactions, indicating that the 3-dehydrogenase is defective in dwf8 plants. Gas Chromatography-Selective Ion Monitoring (GC-SIM) analysis of endogenous BRs in dwf5 plants showed that the level of 24-methylene cholesterol is greatly diminished as compared to wild type, suggesting that the biochemical defect occurs before 24-methylene cholesterol. Similar to dwf5, the biosynthetic defect in dwf7 is also shown to be in a step before 24-methylene cholesterol. The pleiotropic phenotypes in these dwf mutants due to biochemical defects in BR biosynthesis suggests that BRs are essential for proper growth and development of plants.

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Juretic, Nikoleta. "The role of transposons in shaping plant genomes /." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=115687.

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Transposons, also known as transposable elements (TEs), are genetic elements capable of changing their location in the genome and amplifying in number. Because of their ability to cause mutations in the host genome, often with detrimental consequences to the host, yet avoid being eliminated by natural selection, transposons have been labeled selfish elements or genomic parasites. However, the advent of genomics has allowed the identification of numerous instances where transposons have played a crucial role in host genome evolution. In this thesis, I evaluate the extent to which transposons have influenced the genomes of their hosts, with an emphasis on plant genomes. I review the present knowledge of different mechanisms by which this is achieved and provide examples to illustrate them. Next, I tackle the problem of annotating transposons in the completed genomic sequence of domestic rice by comparing RepeatMasker, the standard approach used in transposon annotation, with an alternative approach employing hidden Markov models. In addition, I perform a genome-wide analysis of gene fragment capture by rice Mutator-like transposons. I conclude that, while this is a widespread phenomenon in rice, it is unlikely to represent a major force in generating novel protein-coding genes. Nevertheless, the duplicated gene fragments that are transcribed may playa role in the regulation of host genes they arose from via an RNAi-like mechanism. Finally, I conduct an in silico analysis of a gene family derived from a domesticated Mutator-like transposase, called MUSTANG (MUG), in conjunction with an experimental characterization of the MUG family in Arabidopsis. The results of the study indicate that the MUG family arose in a common ancestor of flowering plants and that the Arabidopsis genes AtMUG1 and/or AtMUG2 may act as global regulators of mitochondrial function. I conclude that our appreciation of the role of transposons in host function and evolution will undoubtedly continue to grow as our understanding of these processes deepens.

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30

Cowan, Rebecca. "Molecular domestication and transposon contributions to plant genome evolution." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82211.

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Despite the ubiquity of transposons in eukaryotic genomes, their evolutionary role remains controversial. The discovery of several domesticated genes has suggested that transposons can gain host functions, and thus contribute to the evolution of their host. Here, I present the results of a genome-wide screen for transposon-derived host genes, which was based on the idea that, once domesticated, the open reading frame of such elements would be maintained, while terminal structures necessary for transposition would be lost. Eight-hundred-and-sixty-three such transposon-dissociated elements were mined from the genome of Arabidopsis thaliana var. Columbia-0, of which less than 10% are associated with expression data. Phylogenetic analysis of Mutator superfamily genes in the genomes of Oryza sativa ssp. japonica (cv Nipponbare) and Arabidopsis, including 121 Mutator-derived transposon-dissociated elements, found that only two gene families are taxonomically widespread. MUSTANG1, a member of one of these families, appears to be under purifying selection. Thus, despite the dearth of taxonomically widespread and/or expressed transposon-dissociated elements, MUSTANG1, as well as three transposon-dissociated elements that may be associated with mutant phenotypes, might be newly discovered transposon-derived host genes.

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31

Horsley, David. "Molecular and structural studies of plant clathrin coated vesicles." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.291323.

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32

Alexander, R. G. "Flow cytometry and cell sorting in plant genetic manipulations." Thesis, University of Nottingham, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356016.

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33

Wint, Ashley A. "Genetic Diversity in Native and Invasive Rubus (Rosaceae)." TopSCHOLAR®, 2008. http://digitalcommons.wku.edu/theses/17.

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Invasive species are an increasing threat to biological diversity as well as a leading cause of recent species’ extinctions. Invasives spread quickly and efficiently, and the U.S spends millions of dollars annually in the control and eradication of these species. More information is necessary in order to predict which species may become invasive. Rubus (Rosaceae) was chosen for study because this genus includes various ploidy levels, reproductive modes, and species that are invasive as well as native. Three Rubus species were chosen to represent apomictic and tetraploid invasives (Rubus armeniacus), a sexual and diploid native species (R. occidentalis), and a sexual and diploid invasive species (R. phoenicolasius). Specimens were collected across the U.S. and two different genetic fingerprinting techniques were used; Amplified Fragment Length Polymorphism (AFLP) and Randomly Amplified Fingerprints (RAF). Using three AFLP primers and two RAF primers, genetic similarity was determined and phylograms were constructed. Through statistical analysis and phylogram data it was determined that there might be slightly more genetic diversity in native R. occidentalis than in invasive R. phoenicolasius. Genetic diversity between apomictic and tetraploid Rubus armeniacus and the two sexual and diploid Rubus species were so similar that no distinction could be made, although the mean pairwise distances and mean number of alleles were significantly different. It was also found that geographic distance and genetic similarity do not appear to be related in these three Rubus species. During the course of this study it was also observed that the AFLP technique produced more alleles than the RAF technique, although this difference was not significant.

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34

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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35

Wambach, Tina. "Effects of epistatic interaction on detection and parameter analysis of quantitative trait loci." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33039.

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Recent scientific support for the involvement of genetic locus interaction in quantitative trait variation and the widespread use of quantitative trait locus (QTL) mapping has resulted in the need to examine those aspects concurrently. Computer software was written to simulate interacting quantitative trait loci (QTLs) in plant populations. Using this software, interacting QTLs were simulated to examine effects of epistasis on the detection of QTLs and the quality of QTL parameter estimates. Simulations involved doubled haploid populations exhibiting two non-epistatic traits and seven epistatic traits, each trait at four levels of heritability. Detection efficiency of QTL main and interaction effects decreased with decreasing heritability. At a given level of broad-sense heritability, traits differed with respect to the relative quality of main-effect detection and interaction-effect detection. Main-effect detection was notably poor for one epistatic locus that has a relatively small additive effect. Position estimates were accurate but their precision deteriorated with decreasing heritability. The quality of QTL effect estimates declined consistently with decreasing heritability, and loss in the accuracy was associated with losses in power of detection.

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36

Huang, Shuai. "Using chemical genetics to discover regulators in plant immunity." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44065.

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37

Harrison, Cecily Jill. "Developmental genetics and evolution of plant form in Streptocarpus." Thesis, University of Edinburgh, 2002. http://hdl.handle.net/1842/14005.

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The mechanisms by which genetic mutation translates to morphological variation between species are poorly understood, but there is increasing support for the involvement of homeobox genes in generating morphological novelty. Homologues of a knotted-like homeobox gene, that is involved in determining meristem identity in model plants, were isolated from different species of Streptocarpus which show marked morphological variation, and these were named Sknox1 genes. Crosses were made between two species with different form, which suggested that their differences were determined by two loci, consistent with previous reports. To test whether Sknox1 was involved in generating morphological differences between species of Streptocarpus, its expression was analysed in three species with different growth form. This showed conventional expression in a species with caulescent form, but novel patterns of expression in that in species with one-leafed or rosette-like form. Differences in expression of Sknox1 therefore correlate with interspecific differences in form. Genetic analysis demonstrated that Sknox1 did not directly cause morphological differences between species. Sknox1 introns showed substantial variation between species. Intron sequences showed evidence of concerned evolution and sometimes contained a repetitive element that may have arisen by gene conversion.

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38

Ramburan, Viresh Premraj. "Genetic mapping of adult plant stripe rust resistance in the wheat cultivar Kariega." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53438.

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Thesis (PhD (Agric)) -- Stellenbosch University, 2003.
ENGLISH ABSTRACT: Stripe (yellow) rust of wheat, caused by Puccinia striiformis f.sp. tritici, was first detected as a single introduction into South Africa in 1996. Two additional pathotypes have since been identified. Control of the disease may be achieved by use of genetic adult plant resistance (APR) as is present in the local cultivar 'Kariega'. The aim of this project was to understand the genetic basis of the APR in 'Kariega' to facilitate breeding of new varieties with genetic resistance to stripe rust. A partial linkage map of a 'Kariega X Avocet S' doubled haploid population covering all 21 wheat chromosomes was generated using 208 DNA markers, viz, 62 SSR, 133 AFLP, 3 RGA and 10 SRAP markers, and 4 alternative loci. The different marker techniques detected varying polymorphism, viz, overall SSR: 46%, AFLP: 7%, SRAP: 6% and RGA: 9%, and the markers produced low levels of missing data (4%) and segregation distortion (5%). A significant feature of the linkage map was the low polymorphism found in the D genome, viz, 19% of all mapped DNA markers, 11% of all AFLP markers and 30% of the total genome map distance. A region exhibiting significant segregation distortion was mapped to chromosome 4A and a seedling resistance gene for stem rust (Puccinia graminis f.sp . tritici), Sr26, mapped to chromosome 6A close to three SSR markers. The leaf tip necrosis gene, Ltn, which was also segregating in the population, mapped to chromosome 7D. Protocols for SRAP and RGA were optimised, and SRAP marker use in wheat genetic linkage studies is reported for the first time. The linkage map was used together with growth chamber and replicated field disease scores for QTL mapping. Chromosomes showing statistically significant QTL effects were then targeted with supplementary SSR markers for higher resolution mapping. The quality of disease resistance phenotypic data was confirmed by correlation analysis between the different scorers for reaction type (0.799±0.023) and for transformed percentage leaf area infected (0.942±0.007). Major QTL were consistently identified on chromosome 7D (explaining some 25-48% of the variation) and on chromosome 2B (21-46%) using transformed percentage leaf area infected and transformed reaction type scores (early and final) with interval mapping and modified interval mapping techniques. Both chromosomal regions have previously been identified in other studies and the 7D QTL is thought likely to be the previously mapped APR gene Yr 18. Minor QTL were identified on chromosomes lA and 4A with the QTL on 4A being more prominent at the early field scoring for both score types. A QTL evidently originating from 'Avocet S' was detected under growth chamber conditions but was not detected in the field, suggesting genotype-environment interaction and highlighting the need for modifications of growth chamber conditions to better simulate conditions in the field. The genetic basis of the APR to stripe rust exhibited by 'Kariega' was established by mapping of QTL controlling this trait. The linkage map constructed will be a valuable resource for future genetic studies and provides a facility for mapping other polymorphic traits in the parents of this population with a considerable saving in costs.
AFRIKAANSE OPSOMMING: Streep of geelroes van koring word veroorsaak deur Puccinia striiformis f. sp tritici, en is die eerste keer in 1996 in Suid-Afrika na introduksie van 'n enkele patotipe waargeneem. Twee verdere patotipes is sedertdien in Suid-Afrika gei"dentifiseer. Beheer van die siekte word veral moontlik gemaak deur die gebruik van genetiese volwasseplantweerstand soos gei"dentifiseer in die plaaslike kultivar 'Kariega'. Die doel van hierdie studie was om die genetiese grondslag van die streeproesweerstand te ontrafel ten einde die teling van nuwe bestande kultivars moontlik te maak. 'n Verdubbelde haplo1ede populasie uit die kruising 'Kariega X Avocet S' is aangewend om 'n gedeeltelike koppelingskaart vir die volle stel van 21 koring chromosome saam te stel. Die kaart het uit 208 DNA merkers, nl., 62 SSR, 133 AFLP, 3 RGA, 10 SRAP merkers en 4 ander lokusse bestaan. Totale polimorfisme wat deur die verskillende merkersisteme opgespoor is, was as volg: SSR: 46%, RGA: 9%, AFLP: 7% en SRAP: 6%. Die mate van ontbrekende data was gering (4%) asook die mate van segregasie distorsie (5%) van 'n enkele geval wat op chromosoom 4A gekarteer is. 'n Prominente kenmerk van die koppelingskaart is die relatiewe gebrek aan polimorfiese merkers op die D-genoom, nl., slegs 19% van alle DNA merkers en 11% van alle AFLP merkers wat slegs 30% van die totale genoom kaartafstand bestaan het. Die stamroes (Puccinia graminis f. sp. tritici) saailingweerstandsgeen, Sr26, karteer op chromosoom 6A naby drie SSR merkers. Die geen vir blaartipnekrose, Ltn, karteer op chromosoom 7D. Protokolle vir SRAP en RGA merkers is ge-optimiseer en gebruik van SRAP merkers in koppelings-analise word vir die eerste keer in koring gerapporteer. Die koppelingskaart is in kombinasie met groeikamerdata en gerepliseerde veldproefdata gebruik om die gene (QTL) vir volwasseplant streeproesweerstand te karteer. Chromosome met statisties betekenisvolle QTL is met aanvullende SSR merkers geteiken om die resolusie van kartering verder te verhoog. Die kwaliteit van fenotipiese data, soos in die proewe aangeteken, is bevestig deur korrelasies te bereken tussen lesings geneem deur onafhanklike plantpataloe (0.799 ± 0.023 vir reaksietipe en 0.942 ± 0.007 vir getransformeerde persentasie blaaroppervlakte besmet). Hoofeffek QTL vir die twee maatstawwe van weerstand is deur middel van die metodes van interval QTL kartering en gemodifiseerde interval QTL kartering konsekwent op chromosome 7D (25-48% van variasie verklaar) en 2B (21-46% van variasie verklaar) ge"identifiseer. In vorige studies is aangetoon dat beide chromosome 7D en 2B QTL vir volwasseplant streeproesweerstand dra. Die 7D QTL is waarskynlik die weerstandsgeen, Yr 18. QTL met klein effekte op weerstand is op chromosome lA en 4A ge"identifiseer. Die effek van laasgenoemde geen was meer prominent in die velddata in die vroee datum van weerstandsbeoordeling. Een QTL, afkomstig van 'Avocet S', is slegs onder groeikamertoestande identifiseerbaar. Dit dui op moontlike genotipe-omgewing wisselwerking en beklemtoon die noodsaaklikheid om aanpassings te maak in groeikamertoestande vir beter simulasie van veldproeftoestande. Die genetiese grondslag van volwasseplantweerstand teen streeproes in die kultivar 'Kariega' is deur QTL kartering bepaal. Die 'Kariega X Avocet S' koppelingskaart kan as 'n waardevolle basis dien vir toekomstige genetiese ontledings van ander polimorfiese kenmerke in die populasie.

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39

Sharma, Jyotsna. "Mycobionts, germination, and conservation genetics of federally threatened Platanthera praeclara (Orchidaceae) /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3060142.

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40

Wilson, F. D., and H. M. Flint. "Host Plant Resistance." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219754.

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The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.
Cotton breeding stocks were evaluated for resistance to pink bollworm. Resistance is being transferred into improved agronomic stocks.

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41

Robson, Julia. "The construction of an expression vector for the transformation of the grape chloroplast genome." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53621.

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Thesis (MSc)--University of Stellenbosch, 2003.
ENGLISH ABSTRACT: The genetic information of plants is found in the nucleus, the mitochondria, and the plastids. The DNA of plastids is comprised of multiple copies of a double-stranded, circular, prokaryoticallyderived genome of -150 kb. The genome equivalents of plastid organelles in higher plant cells are an attractive target for genetic engineering as high protein expression levels are readily obtained due to the high genome copy number per organelle. The resultant proteins are contained within the plastid organelle and the corresponding transgenes are inherited, in most crop plants, uniparentally, preventing pollen transmission of DNA. Plastid transformation involves the uniform modification of all the plastid genome copies, a process facilitated by homologous recombination and the non-Mendelian segregation of plastids upon cell division. The plastid genomes are in a continuous state of inter- and intra-molecular exchange due to their common genetic complement. This enables the site-specific integration of any piece of DNA flanked by plastid targeting sequences, via homologous recombination. The attainment of homoplasmy, where all genomes are transformed, requires the inclusion of a plastid-specific selectable marker. Selective pressure favouring the propagation of the transformed genome copies, as well as the random segregation of plastids upon cell division, make it feasible to acquire uniformity and hence genetic stability. From this, a complete transplastomie line is obtained where all plastid genome copies present are transgenic, having eliminated all wild-type genome copies. The prokaryotic nature of the chloroplast genetic system enables expression of multiple proteins from polycistronic mRNAs, allowing the introduction of entire operons in a single transformation. Expression cassettes in vectors thus include single regulatory elements of plastid origin, and harbour genes encoding selectable and screenable markers, as well as one or more genes of interest. Each coding region is preceded by an appropriate translation control region to ensure efficient translation from the polycistronic mRNA. The function of a plastid transformation vector is to enable transfer and stable integration of foreign genes into the chloroplast genomes of higher plants. The expression vector constructed in this research is specific for the transformation of the grape chloroplast genome. Vitis vinifera L., from the family, Vitaceae, is the choice species for the production of wine and therefore our target for plastid transformation. All chloroplast derived regulatory elements and sequences included in the vector thus originated from this species.
AFRIKAANSE OPSOMMING: Die genetiese inligting van plante word gevind in die kern, die mitochondria, en die plastiede. Die DNA van plastiede bestaan uit veelvuldige kopieë van 'n ~ 150 kb dubbelstring, sirkulêre genoom van prokariotiese oorsprong. Die genoomekwivalente van plastiede in hoër plante is 'n aantreklike teiken vir genetiese manipulering, aangesien die hoë genoom kopiegetal per organel dit moontlik maak om gereeld hoë vlakke van proteïenuitdrukking te verkry. Hierdie proteïene word tot die plastied beperk, en die ooreenstemmende transgene word in die meeste plante sitoplasmies oorgeërf, sonder die oordrag van DNA deur die stuifmeel. Plastied transformasie behels die uniforme modifikasie van al die plastied genoomkopieë, 'n proses wat deur homoloë rekombinasie en die nie-Mendeliese segregasie van plastiede tydens seldeling gefasiliteer word. As gevolg van die gemeenskaplike genetiese komplement, vind aanhoudende interen intra-molekulêre uitruiling van plastiedgenome plaas. Dit maak die setel-spesifieke integrasie, via homoloë rekombinasie, van enige stuk DNA wat deur plastied teikenvolgordes begrens word, moontlik. Vir die verkrying van homoplasmie, waar alle genome getransformeer is, word die insluiting van 'n plastiedspesifieke selekteerbare merker benodig. Seleksiedruk wat die vermeerdering van die getransformeerde genoomkopieë bevoordeel, en die lukrake segregasie van plastiede tydens seldeling, maak dit moontlik om genetiese stabiliteit en uniformiteit van die genoom te verkry. Dit kan op sy beurt tot die verkryging van 'n volledige transplastomiese lyn lei, waar alle aanwesige plastiedgenome transgenies is, en wilde tipe genoomkopieë geëlimineer is. Die prokariotiese aard van die chloroplas genetiese sisteem maak die uitdrukking van veelvuldige proteïene vanaf polisistroniese mRNAs moontlik, wat die toevoeging van volledige operons in 'n enkele transformasie toelaat. Uitdrukkingskassette in vektore bevat dus enkel regulatoriese elemente van plastied oorsprong, gene wat kodeer vir selekteerbare en sifbare merkers, asook een of meer gene van belang (teikengene). Voor elke koderingsstreek, is daar ook 'n toepaslike translasie beheerstreek om doeltreffende translasie vanaf die polisistroniese mRNA te verseker. Die funksie van 'n plastied transformasie vektor is om die oordrag en stabiele integrasie van transgene in chloroplasgenome van hoër plante moontlik te maak. Die uitdrukkingsvektor wat in hierdie studie gekonstrueer is, is spesifiek vir die transformasie van die druif chloroplasgenoom. Vitis vinifera L., van die familie Vitaceae, is die voorkeur species vir die produksie van wyn, en daarom die teiken vir plastied transformasie. Alle chloroplast-afgeleide regulatoriese elemente en volgordes wat in hierdie vektor ingesluit is, het huloorsprong vanaf VUis vinifera L.

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42

Escaler, Margarita. "Changes in host gene expression associated with plant virus replication." Thesis, University of East Anglia, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302215.

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43

Gartland, J. S. "Introduction and use of selectable markers in plant genetic manipulation." Thesis, University of Nottingham, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233705.

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44

Poole, Deborah Marie. "Molecular analysis of plant cell wall hydrolases of bacterial origin." Thesis, University of Newcastle Upon Tyne, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238939.

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45

Quintana, Aguirre Emilio. "Arabidopsis thaliana and the origins of plant genomics in Europe." Thesis, University of Sussex, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310671.

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46

Subramanian, Nithya. "Genetics of mineral accumulation in potato tubers." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/28113/.

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As a major food source potato delivers significant levels of minerals to the human diet. The aim of this study was to understand the control over the mineral concentrations found in tubers. The three-dimensional patterns of mineral distribution in tubers give clues to the processes leading to storage in the tuber. Within the tuber flesh, calcium and phosphorus content decreased towards the centre of the tuber (on FW basis). The elements iron, magnesium, zinc, manganese, sulphur and chlorine were higher at the stem end, while potassium was higher at the bud end. Remobilisation of minerals within the tuber was evident after six months of cold storage. Mineral variation was explored in potato germplasm. Three diverse germplasm collections, the Commonwealth Potato Collection, the Phureja and Tuberosum Core Collection and the Neotuberosum Population demonstrated wide variation for tuber mineral concentrations, an interaction with tuber yield and, on multivariate analysis, consistent parallels between some minerals suggesting unsuspected shared processes affecting their concentrations. The 12601ab1 x Stirling tetraploid mapping population was used to identify QTls for tuber mineral concentration using REML analysis to account for local field variation. Transgressive segregation for tuber mineral concentrations was detected. The genetic map for this population was extended using DArT markers and QTLs were identified on all 12 linkage groups for all minerals studied. Two bulk segregant analyses were performed to add precision to the QTL analysis. One approach identified candidate genes on the potato genome sequence and used nearby SSRs to seek association in the tetraploid mapping population. A second approach used the variation present in the highly diverse Neotuberosum Population to identify DArT markers which were associated with the tails of the distribution of minerals. Using the latter approach, single superscaffolds containing candidate loci and trait-associated DArT markers could be aligned with a small part of mapping population QTLs, providing additional resolution.

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47

Zheng, Liansheng 1955. "Gene expression in two different genotypes of alfalfa under salt stressed and unstressed conditions." Thesis, The University of Arizona, 1988. http://hdl.handle.net/10150/276936.

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Gene expression in two different genotypes of alfalfa, salt-tolerant and salt-sensitive, was examined by studying differences in protein products coded for by poly(A+) RNA isolated from shoot and root tissue. Plants were grown in hydroponics under unstressed or salt-stressed conditions. Two salinity levels (low salt: 30 mM NaCl and 6 mM CaCl2 and high salt: 133 mM NaCl and 27 mM CaCl2) and one unstressed control were applied. The salt-tolerant genotype showed higher biomass accumulation than the salt-sensitive genotype under both control and salt-stressed conditions. The difference in biomass accumulation between the two genotypes was greatest at the highest salt level. The effect of salt stress on gene expression was studied via in vitro translation of poly (A+) RNA with (35S) -methionine. The labeling pattern was similar in all treatments when analyzed by one dimensional SDS-PAGE. However, a two dimensional analysis (isoelectric focusing followed by SDS-PAGE) showed that salt-stress induced a number of new proteins and repressed several others.

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48

Mayo, Oliver. "Contributions to quantitative and population genetics : a collection of publications with introduction." Title page, contents and introduction only, 1987. http://web4.library.adelaide.edu.au/theses/09SD/09sdm473.pdf.

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Title from container. Includes bibliographies and indexes. Contributions to quantitative and population genetics -- The biochemical genetics of man -- The theory of plant breeding -- Natural selection and its constraints.

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49

Sheldon, Candice Claire. "Hammerhead mediated self-cleavage of plant pathogenic RNAs /." Title page, contents and summary only, 1992. http://web4.library.adelaide.edu.au/theses/09PH/09phs544.pdf.

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50

Bullock, James Michael. "The maintenance of genotypic diversity in a clonal plant." Thesis, University of Liverpool, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279711.

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