Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 16 of 16 for “"Sporophytes"”.
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Tolerance and Accumulation of Copper, Lead and Zinc by Ceratopteris richardii
… of Ceratopteris richardii gametophytes and sporophytes to tolerate copper, lead and zinc and for the sporophytes to accumulate the three metals in their shoots. Spores were sown in plant medium treated with varying concentrations of Cu, Pb and Zn. Fifteen-day- old sporophytes were …
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Aspects of growth and production of Laminaria pallida (Grev.) J. Ag. off the Cape Peninsula
… chemical composition and annual production by sporophytes of Laminaria pallida at different localities and depths have been investigated. Growth of L. pallida fronds measured as rates of frond elongation was seasonal and showed similar trends at Robben Island and Oudekraal and at different …
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PHYSIOLOGICAL STUDIES USING TISSUE CULTURES OF PLATYCERIUM CORONARIUM (KOENIG) DESV
… resulting in a decrease in th, percentage of sporophytes produced. The presence of ethylene action inhibitor, silver thiosulphate, in the culture medium resulted in an increase in the percentage of plants regenerated, indicating an inhibitory effect of ethylene on regeneration. Inhibitors of …
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A biological study of Desmarestia firma (C.Ag.) Skottsb. (Phaeophyceae, Desmarestiales)
… one or perhaps more eggs. Trichothallic sporophytes are fused to the female gametophytes. Specimens were cultured to a stage where they produced rhizoids and cortication became apparent. This is the first description of the life-history of a branched, ligulate Desmarestia species, and …
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How reliable is morphological species delimitation in kelp? : a study of two closely related South African Ecklonia species
… separation of hollow and solid-stiped sporophytes provide good evidence for morphological differentiation of E. radiata and E. maxima. While E. radiata clusters morphometrically, a distinction between Australian and South Africa specimens is observed. In localities where the two species …
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Elevated temperatures create bottlenecks in the life history of bull kelp (Nereocystis luetkeana, Phaeophyceae)
… on the development of gametophytes and young sporophytes cultured from field-collected sori over four weeks. The density of female gametophytes declined significantly at 15°C and 18°C, while the density of male gametophytes remained consistent across temperatures, leading to greatly reduced …
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Physiological effects of climate change and estimations of carbon standing stock of southern Salish Sea kelps
… growth, and photophysiology. As with the sporophytes, the effects of acidification were subtle and strongly temperature-dependent. Unlike in sporophytes, we observed positive effects of warming: high temperatures stimulated metabolic rates, leading to more rapid germination, higher growth …
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Studies on maize beta glucosidase gene-enzyme system
… ß-D-glucosides. The enzyme expressed in maize sporophytes is encoded by a highly polymorphic locus, Glul (chromosome 10). In the present study, maize ß-glucosidase was purified to homogeneity by using differential solubility and chromatography. The enzyme is soluble and synthesized adaptively …
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Evolution of life history strategies in Lophoziaceae
… sporophyte frequency; monoicous species produce sporophytes more frequently than dioicous species. A negative relationship was shown to generally exist between spore size and number of spores produced per capsule at both species and population levels. However, no relationship could be established …
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Tropical bracken, a powerful invader of pastures in South Ecuador: Species composition, ecology, control measures, and pasture restoration
… rain forest, vigorously sprouting bracken sporophytes were observed. These developed from gametophytes, which germinated from the wind dispersed spores. Fast growth of the young sporophytes established the fern in the areas. After planting pasture grass, bracken was supported by repeated …
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The biosystematics of pteridophytes: aspects of morphology and reproductive biology of some epiphytic ferns
… and one source of C. angustifolium produce sporophytes mainly through intergametophytic mating whereas P. aureum, P. scolopendria and another source of C. angustifolium undergo intragametophytic selfing. Reproduction in C. phyllitidis is both intergametophytic and intragametophytic. Both …
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Development of intermonoploid somatic hybrids of potato and their molecular analysis based on polymorphism for retroelement Tst1
… and deleterious genes but generates sterile sporophytes, necessitating protoplast fusion for SH development. From six intermonoploid electrofusion combinations, 276 plants were regenerated over 6-9 months. Fusion conditions were optimized. Ploidy was determined by flow-cytometry and SH …
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Evolution of stomata in mosses (Bryophyta): From molecules to form and function
… gas exchange are more pronounced in Oedipodium sporophytes and support the role of stomata in gas exchange and water transport during development and maturation. The second study examines changes in pectin composition during development in the model moss Funaria. Stomatal movement in …
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Systematics, biogeography and morphological evolution in Entosthodon Schwägr. (Bryopsida, Funariaceae) with a revision of the genus in Africa
… recent work on the Funariaceae suggests that the sporophytes, long used as the main basis for classification and identification in the group, exhibit high levels of homoplasy and that Entosthodon is paraphyletic as currently circumscribed. I further test the monophyly of Entosthodon, and its …
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COMPARATIVE ULTRASTRUCTURE OF APICAL CELLS AND DERIVATIVES IN BRYOPHYTES, WITH SPECIAL REFERENCE TO PLASMODESMATA
… network of PD (LPD) group designated for sporophytes of monilophytes and Selaginella (heterosporous lycophyte) with single ACs. Takakia lepidozioides leafy shoot has a tetrahedral AC with a highly curved free surface. This peculiar moss has mucilage hair (MH) associated with axil of …
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Evolution of the Neckeraceae (Bryopsida)
… to most other mosses, where archegonia and sporophytes develop terminally on the main axis (acrocarpous) or on major branches (cladocarpous). Traditionally, pleurocarpous mosses have been divided into three orders based mainly on their sporophytic characters. Brotherus described the …