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.

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.

M.Sc. (Botany) / Please refer to full text to view abstract

Production of secondary metabolites in plant tissue cultures The goal of this study is to determine the influence of sodium molybdate and sodium tungstate as elicitors on production of scopoletin in cell suspension culture of Angelica archangelica L. The culture was grown in a liquid culture medium Murashige and Skoog on a roller apparatus in the dark and light. The content of scopoletin was in cells and in the culture medium determined by high performance liquid chromatography with fluorometric detection. The results show that sodium molybdate served as an elicitor to the production of scopoletin positively, application of sodium tungstate did not increase scopoletin production in any case. The highest production of scopoletin after application of sodium molybdate versus the control cells was reached in the suspension culture of Angelica archangelica L. cultured in the dark at a concentration of 25,50 mg/l. Scopoletin content increased by 166,7 %. After application of sodium tungstate the production always decreased, in the medium of a suspension culture of Angelica archangelica L. cultivated in the light at a concentration of 66.00 mg/l, the production decrease was by up 62,5 %.

De novo shoots, roots, and flower buds were regenerated on thin cell layer explants excised from pedicel tissue of tomato. Direct shoot organogenesis was greatest when media contained 10µM kinetin and 0.001µM indole-3-acetic acid (IAA); however, shoot regeneration was increased in subsequent experiments by substituting 10 µM zeatin or 10 µM benzyladenine for kinetin. Root formation occurred when media contained higher (0.1 and 10µM) auxin concentrations. Flowers were formed on elongated shoots with several leaves when media contained 10µM IAA and 0.1µM kinetin. Competence for de novo shoot morphogenesis was tested on thin cell layers of eleven tomato cultivars. All tomato cultivars formed shoots directly on thin cell layer explants at varying frequencies (29%-63%). The mean number of shoots per explant was greatest for 'Large Red Cherry', 'Ohio 7814' and 'BL 6807', and poorest for 'Campbell 1327' and 'Red Alert'. Active cell divisions were observed in subepidermal cells during the first week of culture, and meristematic centers of dividing cells were evident after 2 weeks. Well developed shoot apices were observed on 50% of the explants 4 weeks after culture initiation. Shoot morphogenesis was compared among tomato plants placed into micropropagation, callus, and thin cell layer tissue culture systems. More shoots were produced on thin cell layer explants than on cotyledon calli, or micropropagated shoot tips. Genetic recombination rates and map distances were compared among hybrid plants grown in the greenhouse and regenerated from the aforementioned tissue culture systems. Increased recombination rates and map distances were detected between the sunny (sy) and baby leaf syndrome (bls) genes on chromosome 3, and between the white virescence (wv) and anthocyanin reduced (are) genes on chromosome 2. The percent change in the former ranged from 4.5%-5.9% for micropropagated shoot tips, 3.7%-8.5% for plants from cotyledon calli and 2.8%-5.9% for plants from thin cell layers. The percent change between the wv and are loci ranged from 4.5%-6.1% for micropropagated shoot tips, and 3.2%-5.0% and 3.9%-5.7% for plants from cotyledon calli and thin cell layers, respectively. Conversely, a decreased map distance was observed between bls and the solanifolia (sf) locus which is more distal to the centromere on the same arm of chromosome 3 as bls. Changes in recombination rates among plants regenerated from tissue culture may result from an influence of the tissue culture process on meiosis of regenerated plants. / Ph. D.

Propagation by tissue culture is effective for many woody ornamental plants, but propagules often become desiccated and die during the acclimatization period. This loss is due in part to stomata that fail to close in response to the reduced humidity outside of the culture environment. KCl was used in in vitro treatments to determine if an additional K supply would improve microshoot stomatal function and water status during acclimatization. The effects of the KCl treatments upon subsequent microshoot rooting and percent fresh weight gain were also evaluated. In preliminary experiments, microshoots of the flame azalea (Rhododendron calendulaceum) were subcultured onto modified Woody Plant Medium amended with a wide range of KCl concentrations for various time periods. It was determined that microshoots did not grow well when cultured at in vitro KCl levels above 50 mM, so treatments were adjusted to 0, 30, and 60 mM KC1, with 9 days of in vitro exposure. After treatment, percent tissue K was determined by atomic absorption spectrophotometry and microshoot water potentials were measured by thermocouple psychrometry. The capacity for the microshoots to resist desiccation after in vitro KCl treatment was determined by percent rooting and fresh weight gain after exposure to dehydration stress, and by gravimetric weight loss of microshoots placed in isopiestic tubes. In addition, microshoots from in vitro KCl treatments were evaluated for percent stomatal closure and water potential during a 38-day acclimatization period. In vitro KCl treatments induced elevated tissue K levels in microshoots and reduced microshoot water potentials, but it could not be shown that these effects specifically enabled the microshoots to resist desiccation. Rooting and percent fresh weight gain were not affected by in vitro treatments, nor was gravimetric weight loss. Microshoot maturation, as a function of days out of culture, had the greatest effect upon increased stomatal function, which, coupled with the onset of rooting, improved microshoot water status. / Master of Science

The physiological responses of Myriophyllum spicatum to 2,4-D, diquat and copper were quantified using a plant tissue viability assay, and daily measures of dissolved oxygen and pH. Correlations of herbicide tissue residues to physiological response measures were determined and the relationship was used to develop exposure-response models. Diquat and copper had a greater effect on plant tissue viability than was observed for 2,4-D. Diquat produced greater reductions in dissolved oxygen concentrations and pH values than 2,4-D or copper. Copper exposure had the least effect on these parameters. Exposure-response models developed for 2,4-D predicted effective control at plant tissue residues ranging from 4000 to 4700 mg/kg. Aqueous exposure concentrations necessary to produce effective control plant tissue residues ranged from 0.20 to 0.40 mg/L. Exposure-response models developed for diquat predicted effective control at plant tissue residues ranging from 225 to 280 mg/kg. Aqueous exposure concentrations necessary to produce effective control plant tissue residues ranged from 0.113 to 0.169 mg/L. Exposure-response models developed for copper predicted effective control at plant tissue residues ranging from 680 to 790 mg/kg. Aqueous exposure concentrations necessary to produce effective control plant tissue residues ranged from 0.32 to 0.64 mg/L. Model predictions for 2,4-D, diquat and copper were within 0.5 mg/L of the manufacturers' label recommendations for these herbicides. The use of laboratory microcosms in development of exposure-response models for diquat and copper produced results comparable to those using the larger-scale greenhouse systems. Diquat effectively controlled M. spicatum at lower tissue residues than 2,4-D or copper. In addition, initial aqueous exposure concentrations were also lower for diquat. Use of these models in field situations should be coupled with considerations of quantity of biomass present and environmental conditions, such as turbidity, in order to accurately calculate exposure concentrations necessary for effective tissue residues. Thus, the use of these models can be used to optimize the impact on the target species while minimizing exposure for nontarget species.

Call number: LD2668 .T4 1984 B46 / Master of Science

Tissue culture and radicle excision techniques were employed to evaluate salt tolerance in alfalfa (Medicago sativa L.). Plant suspension cultures of either seedling root or shoot origin were studied in media with or without supplemental NaCl (3.54 g liter⁻¹). In most cases, the growth rates of root-derived cultures were stimulated by this low level of supplemental NaCl while most shoot-derived cultures were not stimulated by NaCl. Excised radicles of three populations of alfalfa which possessed widely differing ranges of germination salt tolerance were screened in four salts (NaCl, KCl, Na₂SO₄, and K₂SO₄) at six varying concentrations. As was observed in the tissue culture experiments, low levels of NaCl (7.09 g liter⁻¹) stimulated radicle elongation of all populations as compared to the elongation levels of the control solutions (no supplemental salts). In general, for NaCl, the population that posessed the highest degree of germination salt tolerance (Az-St 1982) also displayed the greatest rates of radicle elongation especially in the highest salt concentrations. Additionally, this population along with the moderately germination salt tolerant population (Az-ST 1979) maintained higher rates of elongation in KCl, K₂SO₄ and Na₂SO₄ than did the control germplasm which has little germination salt tolerance (Mesa Sirsa Control). Examinations of each individual population in all four salts simultaneously, indicated that the sulfate salts reduced radicle elongation to a greater extent than did the chloride salts. Evaluation of both osmotic effects and specific ion effects showed that the specific ion effects attributed to the anions were more detrimental to radicle elongation than were the osmotic effects.

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Student: Vendula Damborská Supervisor: PharmDr. Marie Kašparová, Ph.D. Title of diploma thesis: The Optimization of the growth of the plant tissue culture of Juniperus virginiana The main goal of this diploma thesis lies in the optimization of cultivation medium composition for the tissue culture of Juniperus virginiana (varieties 'Hetzii', 'Glauca', 'Grey Owl'). The best results of all tested media were achieved by using Schenk and Hildebrandt medium with an addition of α-NAA (3.0 mg.l-1 ), kinetin (0.2 mg.l-1 ) and ascorbic acid (15.0 mg.l-1 ). The cultures were cultivated at the temperature of 25 řC and light period of 16 hours light/8 hours dark. The growth curve for the tissue culture of Juniperus virginiana 'Glauca' was set for 2 different cases: with and without the addition of phenylalanin (biogenetic precursor of phenylpropans biosynthesis). The maximal growth was reached on 35th day of the cultivation in both cases, phenylalanin increases the growth rate by 29.65 %.