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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.
41

Orgaanspesifieke proteienkinase-aktiwiteite in Triticum aestivum L. kultivar Zaragoza, met spesiale verwysing na die helmknopkultuurtegniek

Bothma, Christiaan 12 March 2014 (has links)
M.Sc. (Biochemistry) / The culture of plant anther tissue in vitro, is an important tool which could be used, when perfectedr in the conventional breeding of crop plants. Using this technique it may be possible to generate bomozygotIc lines in one or two generations in contrast to the seven or eight generations required by conventional breeding programs. Physiological data on the behavior of cultured anther tissue suggests that the genotype is the most Important factor Influencing this factor with respect to wheat barley and most other crop plants. Optimal culture conditions with respect to culture medium and environmental factors have already been established. It would appear that a critical factor, present in the pollen cells of anther tissue, governs the variation and differentiation of the embrionic pollen in the formation of haploid plants. Many important systems of cellular signalling and therefore cellular regulation are mediated by protein kinases and phosphatases. An examination of protein kinase activity in normal and anther tissue may yield information about the process of differentiation. Identification of key kinase activities may provide plant breeders with a means of selecting more responsive genotypes for the use In the anther culture technique In VItro. In this manuscript a caparison is made between protein kinase activities in crude extracts of meristematic...
42

Anther culture of Arabidopsis thaliana on stationary liquid medium.

Keathley, Daniel Elden January 1981 (has links)
No description available.
43

Ovlivnění produkce explantátové kultury Trifolium pratense L. I / Influencing of production of plant tissue culture of Trifolium pratense L. I

Muráriková, Kateřina January 2013 (has links)
1 ABSTRACT Kateřina Muráriková Influencing of production of plant tissue culture of Trifolium pratense L. I The aim of this thesis was to check the influence of cinnamic acid, as a precursor of the phenylpropanoids biosynthesis, on the flavonoids production of Trifolium pratense L. suspension culture, to compare two varieties of this plant, the DO-8 one and the Tempus one, in terms of the effect of this precursor, and to help achieve the successful increase of the production of secondary metabolites by the Trifolium pratense L. explant cultures. Concerning the DO-8 variety, the changes of the isoflavonoids production as a result of the cinnamic acid influence have been also tested. The suspension cultures were being cultivated on the Gamborg's nutrient medium with the addition of 2 mg.l-1 2,4-dichlorphenoxyacetic acid and 2 mg.l-1 6-benzylaminopurine. The cultivation was being realised on a slow moving roller at temperature of 25 řC and in the period of 16 hours of light and 8 hours of dark. The cinnamic acid was added in the four concentrations and its influence was observed after 6, 24, 48 and 168 hours. The flavonoids determination was being applied on the check samples and the samples with the addition of cinnamic acid by the spectrophotometric method in agreement with the Český lékopis 2009 and the...
44

Ovlivnění produkce explantátové kultury Trifolium pratense L. II / Influencing of production of plant tissue culture of Trifolium pratense L. II

Částková, Lucie January 2013 (has links)
Lucie Částková Influencing of production of plant tissue culture of Trifolium pratense L. II The aim of this thesis was to observe the effect of the abiotic elicitor vanadyl sulfate on the production of flavonoids in the suspension culture of Trifolium pratense L., variety DO-8 and variety Sprint. The effects on the production of isoflavonoids caused by the elicitor have been also studied. The cultures were cultivated at the temperature of 25 žC, 16 hour light/8 hour dark period, in the Gamborg's nutriet medium with the addition of 2 mg.l-1 of 2,4- dichlorophenoxyacetic acid and 2 mg.l-1 of 6-benzylaminopurine. Vanadyl sulfate was added in four concentrations and its influence was observed after 6, 24, 48 and 168 hours. The quantity of flavonoids was determined spectrophotometrically according to the Pharmacopoeia Bohemica 2009. The quantity of isoflavonoids was determined using HPLC. The maximal content of flavonoids, 0,459 %, was measured in the suspension culture of Trifolium pratense L., variety DO-8, taken after 48 hours of action of elicitor vanadyl sulfate, which concentration was 1 µmol.l-1 . The statistically significant increase in production was 106 % compared to the control. The production of flavonoids in variety Sprint was most influenced by the action of vanadyl sulfate, which...
45

In vitro and in vivo chemical characterization of kigelia africana, mimusops zeyheri, terminalia sericea and ximenia caffra nuts and nut meals

Chivandi, Eliton 01 February 2013 (has links)
Soyabean meal (SBM), the major protein source in feeds in sub-Saharan Africa, is in short supply. The shortage is a major constraint to intensified animal production to meet increased demand hence the dire need to search for alternatives. Kigelia africana, Mumisops zeyheri, Terminalia sericea and Ximenia caffra are indigenous fruit bearing trees (IFBTs) whose seeds’ potential as alternative protein sources in feeds were evaluated. The evaluation consisted of an initial physico-chemical characterization of the seeds followed by determining in vitro the safety of seed oils on cell lines. Based on the physico-chemical and in vitro evaluation, the most suitable seed was selected, defatted and its meal used as a dietary substitute to SBM in the in vivo trials using adult and weanling male Sprague Dawley rats. The T. sericea seed yield was not viable. Chemically K. africana and X. caffra seed demonstrated potential as protein sources in feeds. M. zeyheri seed demonstrated potential as an energy source. The IFBTs seeds oil yield surpassed that of some traditional oilseed crops. Oleic and linoleic acid were the major fatty acids contained in the oils. In vitro, K. africana, M. zeyheri and X. caffra seed oils suppressed Caco-2 and HEK-293 cell proliferation without causing cell death. X. caffra seed, deemed the most suitable, was defatted and its seed meal used in the in vivo trials. In mature rats, dietary substitution of SBM with the defatted X. caffra seed meal did not affect (P > 0.05) dry matter intake, apparent digestibility of nutrients and nitrogen absorption and retention. In weanling rats, the defatted X. caffra seed meal had no effect on termination (body mass at the end of the feeding trial) and empty carcass mass and linear growth of the rats. Metabolic substrate storage, fasting blood glucose concentration and the general health profile of the growing rats were not altered by dietary X. caffra seed meal. The defatted X. caffra seed meal increased the mass of the stomach and small intestine (P = 0.0071; P = 0.0001) of rats on the test diet where a 100% dietary crude protein (CP) from SBM was substituted by CP from the defatted X. caffra seed meal. Defatted X. caffra seed meal could substitute SBM in rat and possibly monogastrics feeds without compromising digestibility, nitrogen balance, growth and general health.
46

Towards an understanding of the physiological abnormality of tissue cultured plants known as vitrification

Gribble, Karleen D., University of Western Sydney, Hawkesbury, Faculty of Science and Technology January 1999 (has links)
For this research, the abnormality of tissue cultured plantlets,vitrification, was examined in Gypsophila paniculata.Measurement of the relative water content and water saturation deficit of plantlets in culture revealed that vitrified plantlets contain relatively more water and less air spaces than non-vitrified plantlets.The effect of relative humidity on vitrification and growth was investigated using a variety of methods.From the results found, it was determined the defining characteristic of vitrified plantlets is water filled intercellular spaces. It was also determined that the primary cause of vitrification is high relative humidity resulting in a lack of transpiration in vitro but that other factors such as unbalanced mineral nutrition or high medium cytokinin can exacerbate vitrification.Further research in tissue culture may investigate the influence of relative humidity on plant growth and morphology, the mechanism by which plants exclude water from their intercellular spaces and refine in vitro tissue mineral analysis as a means by which critical mineral concentrations can be determined. / Doctor of Philosophy (PhD)
47

Studies on the growth and alkaloid production of tissue cultures of Vinca rosea L. /

Ho, Kit-fong. January 1980 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1981.
48

Studies on the growth and alkaloid production of tissue cultures of Vinca rosea L.

何潔芳, Ho, Kit-fong. January 1980 (has links)
published_or_final_version / Botany / Master / Master of Philosophy
49

Tissue culture studies on Peperomia clusifolia Hook. and Strongylodon macrobotrys A. Gray.

Peters, Deborah. January 1982 (has links)
Tissue culture studies were carried out on two ornamental plant species, Strongylodon macrobotrys A. Gray and Peperomia clusifolia Hook. Successful in vitro regeneration of plantlets was achieved in the latter species, using leaf and stem explants. The basal medium of Murashige and Skoog (1962), in combination with various levels of NAA and K, was utilised. Strongylodon proved refractory to both establishment of a thriving callus culture and in vitro formation of roots and shoots. Several media were utilised, Miller's (1963) medium proving the most successful for the production of callus. Different combinations of the growth regulators NAA, IBA, BA and K were used to determine optimum levels of these substances for callus production. Root/shoot induction studies were carried out using the basal medium of Miller (1963) plus various concentrations of IBA in combination with K or BA. Alternatively,the basal medium was used without added growth regulators. Internodes, nodal segments, leaves, pulvini, flower parts and seeds were used in the study. No plantlets were obtained from Strongylodon explants. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1982.
50

Effects of substituted phenols on growth, bud formation, and indoleacetic acid oxidase activity in tobacco tissue cultures

Lee, Tsung Ting, January 1962 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1962. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 157-167.

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