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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Evaluation of Brassica fibre for textile and spinning properties

Khan, Md Rabiul Islam 13 September 2016 (has links)
Brassica napus L., which is commonly known as canola, is the largest sources of edible oil in Canada. The remaining plant material, such as the stem, remains unused for any immediate application and is returned to the soil for decomposition. An investigation has been conducted to extract, characterize and modify the fibre materials from B. napus stems for textile and apparel applications. In order to find the optimum retting conditions for retting time, four different retting parameters were evaluated including, retting temperature, material liquor ratio, water exchange and the reuse of retted water. It was discovered that the virgin-retted fibres from Brassica plants exhibit most of the required textile properties including dye absorbency, strength, and thermal behaviour. However, the virgin-retted fibres do not exhibit the required spinning (yarn transformation) properties (softness, flexibility and individual fibre entity). In order to modify the Brassica fibres for spinnability, three treatment methods were applied: 1) alkali, acid and softener treatment; 2) pectinase enzyme treatment; and 3) enhanced enzyme treatment. According to Method 5 of the American Association of Textile Chemists and Colorists (AATCC), Brassica fibers obtained from treatments 2 and 3 showed similar spinning properties, and demonstrated superior spinning properties to Brassica fibres obtained from treatment one. To determine the variability of the cultivars upon textile and spinning properties, seeds from twenty different Brassica cultivars consisting of three different species, B. napus, B. juncea L. and B. rapa L., were collected, planted, and harvested upon reaching physiological maturity. The virgin water-retted fibre samples were then treated with pectinase enzyme, and different spinning properties (stiffness, softness, individual fibre entity) and textile properties (fibre decomposition temperature, tenacity and dye absorbency) of enzyme-treated samples were evaluated. The current research suggests that producing fibers from canola stubble and stems could be an additional income source for canola growers. / October 2016
52

INFLUÊNCIA DA NUTRIÇÃO MINERAL COM NITROGÊNIO E BORO NA PRODUTIVIDADE E PRESENÇA DE COMPOSTOS SECUNDÁRIOS POLARES EM Brassica oleracea var. capitata

CASTELUBER, I. P. 25 April 2014 (has links)
Made available in DSpace on 2018-08-01T23:26:44Z (GMT). No. of bitstreams: 1 tese_7392_37 - Dissertação - Ivana20150903-153147.pdf: 528640 bytes, checksum: 7c9c1018c02447ef374e533ce8807566 (MD5) Previous issue date: 2014-04-25 / A família botânica com o maior número de hortaliças são as Brassicaceas. No Brasil, o repolho é a brássica mais consumida e no Espírito Santo é a terceira cultura olerícola de maior expressão. A adubação correta favorece a qualidade do produto final, proporcionando respostas positivas na produtividade com aplicações crescentes. O objetivo deste trabalho foi verificar a influência da adubação nitrogenada e boratada na produtividade do repolho e na produção de metabólitos secundários no norte do Espírito Santo. O experimento foi conduzido na fazenda experimental do curso de agronomia do CEUNES/UFES. Foram usadas sementes do híbrido Astrus plus e as mudas mantidas por cerca de 30 dias na casa de vegetação. Utilizou-se o delineamento de blocos casualizados (DBC) com 5 tratamentos e 4 repetições e as adubações de plantio e cobertura seguiram as normas para o estado do Espírito Santo. Os tratamentos consistiam em 0,75,150,225 e 300 Kg de N.ha-1 e 0, 2, 4, 6 e 8 Kg de B.ha-1 feitas aos 15, 40 e 60 dias após o transplante. As características analisadas foram produtividade, massa fresca da cabeça, diâmetro da cabeça, número de folhas externas, índice de formato, relação altura do coração sobre diâmetro da cabeça, teor de massa seca, de nitrogênio total e de boro da cabeça e das folhas externas e metabólitos secundários. A extração e caracterização cromatográfica das amostras foram feitas na Universidade Federal de Santa Maria. A análise dos resultados mostrou que para ambos os nutrientes as respostas foram significativas para a maior parte dos parâmetros estudados. Os dados de produtividade e qualidade das plantas formadas se mostraram compatíveis com as exigências do mercado consumidor e os metabólitos secundários encontrados apresentaram maior concentração nas folhas externas.
53

Metabolism of cruciferous chemical defenses by plant pathogenic fungi

2012 June 1900 (has links)
Plants produce complex mixtures of secondary metabolites to defend themselves from pathogens. Among these defenses are metabolites produced de novo, phytoalexins, and constitutive metabolites, phytoanticipins. As a counter-attack, pathogenic fungi are able to transform such plant defenses utilizing detoxifying enzymes. This thesis investigates the metabolism of two important cruciferous phytoalexins (brassinin (33) and camalexin (39)) by the phytopathogenic fungus Botrytis cinerea and the metabolism of cruciferous phytoanticipins (glucosinolates and derivatives) by three economically important fungi of crucifers Alternaria brassicicola, Rhizoctonia solani and Sclerotinia sclerotiorum to investigate their role in cruciferous defense. In the first part of this thesis, the transformations of brassinin (33) and camalexin (39) by B. cinerea were investigated. During these studies a number of new metabolites were isolated, their chemical structures were determined using spectroscopic techniques, and further confirmed by synthesis. Camalexin (39) was transformed via oxidative degradation and brassinin (33) was hydrolyzed to indoly-3-methanamine (49). The metabolic products did not show detectable antifungal activity against B. cinerea, which indicated that these transformations were detoxification processes. Camalexin (39) was found to be more antifungal than brassinin (33). In the second part of this thesis, the metabolism of glucobrassicin (86), 1-methoxyglucobrassicin (87), 4-methoxyglucobrassicin (90), phenylglucosinolate (65), and benzylglucosinolate (66), the corresponding desulfoglucosinolates and derivatives by three fungal pathogens (A. brassicicola, R. solani and S. sclerotiorum) was investigated and their antifungal activity against the same pathogens was tested. Aryl iii glucosinolates 65 and 66 were metabolized by A. brassicicola but not by R. solani or S. sclerotiorum, whereas indolylglucosinolates were not metabolized by any pathogen. Indolyl desulfoglucosinolates (159 and 233) were transformed by R. solani and S. sclerotiorum to the corresponding carboxylic acids and indolyl acetonitriles 40, 102, and 103 were also metabolized to the corresponding carboxylic acids by all pathogens. None of the glucosinolates or their desulfo derivatives showed antifungal activity, but some of their metabolites showed low to very high antifungal activities. Among these metabolites, diindolyl-3-methane (113) showed the highest antifungal activity, and benzyl isothiocyanate (170) showed higher inhibitory effect against R. solani and S. sclerotiorum, but did not inhibit the growth of A. brassicicola. The cell-free extracts of A. brassicicola, R. solani, and S. sclerotiorum were tested for myrosinase activity against several glucosinolates. The cell-free extracts of mycelia of A. brassicicola displayed higher myrosinase activity for sinigrin (131), phenyl and benzyl glucosinolates 65 and 66, but lower activities for glucobrassicin (86) and 1-methoxyglucobrassicin (87); no myrosinase activity was detected in mycelia of either R. solani or S. sclerotiorum.
54

Purification of Brassica juncea chitinase BJCHI1 from transgenic tobacco

Fung, King-leung. January 2001 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 115-132).
55

Blackleg of Canola: Survey of virulence and race structure of the Leptosphaeria maculans pathogen population in Canada and evaluation of the genetic variation in the L. maculans global population

Liban, Sakaria 14 September 2015 (has links)
Phoma stem canker (aka Blackleg) caused by the fungal pathogen Leptosphaeria maculans is a major disease affecting Canola (Brassica napus L.). This study examined 674 L. maculans isolates collected in 2010 and 2011 from western Canada at ten avirulence gene loci. Overall, certain alleles were more prevalent with AvrLm6 and AvrLm7 present in >85% of isolates and AvrLm3, AvrLm9, and AvrLepR2 present in <10% of isolates. This study also examined the genetic diversity of Leptosphaeria maculans populations around the world. Blackleg disease is found in most countries where Brassica spp. are cultivated and there are indications that L. maculans is an expanding species displacing the less aggressive Leptosphaeria biglobosa. Twenty two microsatellite primers were used to screen 96 isolates from 8 countries. A phylogenetic tree to assess the evolutionary relationship between regions was generated and the results indicated that genetic diversity was correlated with geographic location. / October 2015
56

Identification of quantitative trait loci for resistance to Sclerotinia sclerotiorum in Brassica napus

Behla, Ravneet 24 June 2011 (has links)
Quantitative trait loci (QTL) analysis for Sclerotinia stem rot resistance was carried out in five doubled haploid (DH) populations of Brassica napus. Sclerotinia stem rot is caused by the necrotrophic fungus Sclerotinia sclerotiorum (Lib.) de Bary. Sclerotinia stem rot has worldwide occurrence and causes significant yield losses in many crop species. Several screening methods have been recommended in the literature to evaluate plant resistance to Sclerotinia stem rot. Four controlled environment based screening methods: 1) excised leaf assay, 2) cotyledon assay, 3) mycelial stem inoculation technique and 4) petiole inoculation technique compared for their ability to differentiate between plant susceptibility/resistance, their reliability and suitability for large scale screening using eight B. napus cultivars/lines of varying reaction to S. sclerotiorum. The petiole inoculation technique and the mycelium stem inoculation technique were identified as reliable methods in this study. Previously developed, five B. napus DH populations (H1, H2, H3, DH179 and DH180) segregating for resistance to Sclerotinia stem rot were used in this study. The petiole inoculation technique was used to evaluate resistance to Sclerotinia stem rot. Data on days to wilting was recorded for a two week period. Twelve plants per line were screened in each evaluation and each population was evaluated three times. Two to three day-old mycelial cultures of S. sclerotiorum isolate Canada 77 was used. QTL analyses were carried out using a LOD threshold value of 2.5 on each individual replicate and on the average of all the replicates. In the H1 population, the number of QTL detected ranged from four to six in each analysis. In the H2 population, there were three to six QTL in each analysis. There were two to six QTL in each analysis of the H3 population. In the DH179 population, the number of QTL detected ranged from three to five in each analysis. In DH180 population, the number of QTL identified varied from three to six in each analysis. A number of common QTL were found between the replicates of each population. Five common QTL were identified between these populations. The markers linked to these QTL are now available for marker assisted selection.
57

QTL mapping, gene identification and genetic manipulation of glucosinolates in Brassica rapa L.

Hirani, Arvindkumar 09 August 2011 (has links)
Glucosinolates are amino acid derived secondary metabolites found in the order Capparales. It is an important class of phytochemicals involved in plant-microbe, plant-insect, plant-animal and plant-human interactions. It is, therefore, important to understand genetic mechanism of glucosinolate biosynthesis in Brassica for efficient manipulation. In this study, QTL mapping of leaf and seed glucosinolates was performed in B. rapa using two RIL populations, SR-RILs and BU-RILs. QTL mapping was performed using SR-RILs developed from a cross of Chinese cabbage and turnip rapeseed and a genetic map in B.rapa. Genetic map was developed using a total 1,579 molecular markers including 9 markers specific to glucosinolate genes, GSL-ELONG, GSL-PRO, GSL-FMOOX1, and GSL-AOP/ALK. Several QTL for progoitrin, gluconapin, glucoalyssin, glucobrassicanapin, 2-methylpropyl and 4-hydoxyglucobrassicin glucosinolates were identified with phenotype variance between 6 and 54%. Interestingly, a major QTL for 5C aliphatic glucosinolates was co-localized with a candidate Br-GSL-ELONG locus on linkage group A3, displayed co-segregation with co-dominant SCAR marker BrMAM1-1. The Br-GSL-ELONG locus was identified to regulate 20 µmole/g seed 5C glucosinolate biosynthesis. BU-RILs derived from a cross of yellow sarson and USU9 was segregated for glucoerucin, gluconapin and progoitrin 4C aliphatic glucosinolates with 4-hydoxyglucobrassicin. Phenotyping was performed in controlled and field environments for seed glucosinolates and controlled environments for leaf glucosinolates. Genetic map was developed using SRAP markers and glucosinolate gene, GSL-ELONG and GSL-PRO specific 4 loci were integrated on map. Four and three QTL were identified for seed glucoerucin and gluconapin, respectively in both environments with phenotypic variance up to 49%. Additionally, genetic manipulation of glucosinolates was performed by backcross with MAS in B. rapa. Resynthesized B. napus line was backcrossed with B. rapa genotypes, RI16, BAR6 and USU9 for replacement or introgression of glucosinolate genes, GSL-ELONG- and GSL-PRO+. In RI16 genotype, 15 to 25 µmole/g seed 5C glucosinolates reduced in 15 BC3F2 lines those were positive with GSL-ELONG- marker and negative with the A-genome and gene specific marker BrMAM1-1. This suggests that the functional allele has replaced by non-functional from B. oleracea. GSL-PRO+ positive backcross lines in RI16 genotype displayed sinigrin 3C aliphatic glucosinolate in B. rapa. This suggests introgression of GSL-PRO+ in B. rapa.
58

Development of linkage map of Brassica juncea using molecular markers and detection of quantitative trait loci for oil content, seed protein and fatty acids

Watts, Roger 28 January 2013 (has links)
A genetic linkage map of mustard (Brassica juncea) was developed using two double haploid populations produced from crosses between a low erucic cultivar “ZEM1” and two moderate erucic acid lines “Vniimk351” and “Vniimk405” with the use of SSR and SRAP markers. The linkage map of the ZEM1xVniimk351 population included 13 linkage groups with an overall length of 791 cM with an average marker interval of 5.7 cM. The linkage map of the ZEM1xVniimk405 population also contained 13 linkage groups with a distance of 623 cM and an average marker interval of 4.6 cM. Using the linkage maps for the two populations, QTLs were detected for seed oil, protein and fatty acids. QTL analysis for fatty acids indentified QTLs on LG1, 7 and 12 for the ZEM1xVniimk351 population and LG1, 3 and 4 for the ZEM1xVniimk405 population. Analysis for the seed oil and protein content in the ZEM1xVniimk351 population identified 2 QTLs on LG1 and LG4 and 1 QTL on LG1 respectively. The QTL analysis ZEM1xVniimk405 of oil and protein content identified 1 QTL for oil and protein on LG1. The variation of fatty acids was shown to be the result of monogenic inheritance of the FAE1 gene in both populations.
59

Analysis of oilseed glucosinolates and their fate during pressing or dehulling

2014 June 1900 (has links)
Brassica carinata (A.) Braun and Camelina sativa (L.) Crantz are two re-emerging oilseed crops of the Brassicaceae family that are being adapted for cultivation in western Canada. Both seeds of these species reportedly accumulate considerable amounts of sulfur-containing secondary metabolites called glucosinolates. The purpose of the current work was to gain knowledge of the occurrence and distribution of glucosinolates during primary processing of these oilseeds, including during pressing and dehulling. In the first study, a reversed phase HPLC method was developed for the analysis of sinigrin, the major glucosinolate in B. carinata. Both C18 columns selected were able to separate the compound with an isocratic eluent containing 100% tetramethylammonium bromide (10 mM, pH 5) delivered at 1 mL/min at a column temperature of 25oC. These chromatographic conditions were applied and sinigrin concentration of whole B.carinata seed was estimated to be 29 μg/mg. Average matrix effect was estimated to be 104% that was caused by other components in the B. carinata seed matrix. In the second study, high concentrations of glucosinolates were detected and identified in fractions of C. sativa seeds using HPLC-ESI-MS. Methods for extraction, isolation, and purification of three individual glucosinolates from these fractions are reported. Quantitation of total glucosinolates was performed on proton NMR using DMF as an internal standard. Quantitation of individual glucosinolates was achieved by using MS extracted ion chromatogram data. Total glucosinolates were found in C. sativa whole seed at a concentration of 14 μg/mg, and glucocamelinin, the major glucosinolate, constituted 65% of the total amount. In addition, a dehulling treatment was applied to C. sativa seeds, from which both oil content and crude protein content increased after dehulling of the seeds.
60

Identification of quantitative trait loci for resistance to Sclerotinia sclerotiorum in Brassica napus

Behla, Ravneet 24 June 2011 (has links)
Quantitative trait loci (QTL) analysis for Sclerotinia stem rot resistance was carried out in five doubled haploid (DH) populations of Brassica napus. Sclerotinia stem rot is caused by the necrotrophic fungus Sclerotinia sclerotiorum (Lib.) de Bary. Sclerotinia stem rot has worldwide occurrence and causes significant yield losses in many crop species. Several screening methods have been recommended in the literature to evaluate plant resistance to Sclerotinia stem rot. Four controlled environment based screening methods: 1) excised leaf assay, 2) cotyledon assay, 3) mycelial stem inoculation technique and 4) petiole inoculation technique compared for their ability to differentiate between plant susceptibility/resistance, their reliability and suitability for large scale screening using eight B. napus cultivars/lines of varying reaction to S. sclerotiorum. The petiole inoculation technique and the mycelium stem inoculation technique were identified as reliable methods in this study. Previously developed, five B. napus DH populations (H1, H2, H3, DH179 and DH180) segregating for resistance to Sclerotinia stem rot were used in this study. The petiole inoculation technique was used to evaluate resistance to Sclerotinia stem rot. Data on days to wilting was recorded for a two week period. Twelve plants per line were screened in each evaluation and each population was evaluated three times. Two to three day-old mycelial cultures of S. sclerotiorum isolate Canada 77 was used. QTL analyses were carried out using a LOD threshold value of 2.5 on each individual replicate and on the average of all the replicates. In the H1 population, the number of QTL detected ranged from four to six in each analysis. In the H2 population, there were three to six QTL in each analysis. There were two to six QTL in each analysis of the H3 population. In the DH179 population, the number of QTL detected ranged from three to five in each analysis. In DH180 population, the number of QTL identified varied from three to six in each analysis. A number of common QTL were found between the replicates of each population. Five common QTL were identified between these populations. The markers linked to these QTL are now available for marker assisted selection.

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