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Thesis (Ph.D. Agriculture (Horticulture)) -- University of Limpopo, 2012 / High yield losses in various crops due to plant-parasitic nematodes are associated with high initial nematode population densities (Pi). Uses of synthetic nematicides to reduce Pi were dependent on the physiological effect of materials on the protected crops, resulting into the coining of pre-emergent and post-emergent nematicides. Crude extracts of wild cucumber (Cucumis myriocarpus) fruit consistently reduced nematode population densities of the southern root-knot nematode (Meloidogyne incognita) when used as a post-emergent bio-nematicide. The purpose of this study was to investigate the compatibility of crude extracts of C. myriocarpus fruit when used as a pre-emergent bio-nematicide on germination and emergence of commercially important dicotyledonous and monocotyledonous crops using empirical tests and computer-generated models. Studies were conducted over a period of three years to assess the effects of this material on growth of various seedlings. Seven treatments comprising crude extracts of C. myriocarpus fruit (0, 2.5, 5, 7.5, 10, 12.5 and 15 g/pot) and test solutions (0, 25, 50, 75, 100, 125 and 150 g/ℓ distilled water) were used for emergence and germination in initial studies. Generally, 18 days after the treatments, variables measured and levels of crude extracts of C. myriocarpus fruit had negative quadratic relationships, which suggested that they had density-dependent growth responses. Subsequent studies were conducted using three selected crops each from the families Alliaceae, Gramineae and Solanaceae under greenhouse conditions, each with reduced concentration of 10 treatments (0, 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75, 2.00 and 2.25 g material/pot). Using variables of various organs and crops, significant means were subjected to the Curve-fitting Allelochemical Dosage Response (CARD) computer model, which was characterised by six biological indices, viz. threshold stimulation (Dm), xli saturation level (Rh), 0% inhibition (D0), 50% inhibition (D50), 100% inhibition (D100) and transformation level (k). The model demonstrated that the responses of the three crops from each family when regressed to dosages of crude extracts of C. myriocarpus fruit exhibited the density-dependent growth patterns, characterised by responses that included stimulation, saturation and inhibition. The integrated sensitivities (Σk) of the tested crops to crude extracts of C. myriocarpus fruit ranged from Σk = 9 to Σk = 51, with eggplant (Solanum melongena) and sorghum (Sorghum bicolor) being the most sensitive, while tomato (Solanum lycopersicum) was the least sensitive. Using the data depicting the stimulation range from CARD model, viz. (Dm), which is a threshold stimulation dosage and (Rh), which is a saturation dosage, mean dosage stimulation response (MDSR) was determined for chive (Allium schoenoprasum), leek (Allium ampeloprasum), onion (Allium cepa), maize (Zea mays), millet (Panicum miliaceum), sorghum, eggplant, pepper (Capsicum annum) and tomato as being 1.19, 0.68, 0.45, 1.13, 0.86, 1.12, 0.74, 1.11, and 0.53 g, respectively. These MDSR values are dosages which when applied for respective crops at direct seeding would not affect germination or emergence. MDSR values were validated for onion, millet and tomato, resulting in approximately 100% suppression of nematodes in all three test crops. In contrast, 100% emergence occurred in millet and tomato, while the validated MDSR reduced emergence on onion by 15%, which confirmed the sensitivity of this crop to crude extracts of C. myriocarpus fruit. In conclusion, crude extracts of C. myriocarpus fruit have the potential for use as pre-emergent bio-nematicide in suppression of plant-parasitic nematodes in various crops.

Call number: LD2668 .T4 1963 S53 / Master of Science

Pak-chung Leung. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 151-158). / Abstract --- p.i / Acknowledgments --- p.iii / Table of contents --- p.iv / List of Figures --- p.viii / List of Tables --- p.ix / List of Abbreviations --- p.xiv / Chapter / Chapter 1. --- General Introduction --- p.1 / Chapter 2. --- Literature Review: Greening process in higher plants --- p.4 / Chapter 3. --- Greening Bioassay in Excised Cucumber Cotyledons / Introduction --- p.13 / Materials and Methods / Plant material --- p.14 / Measurement of Ch1 synthesizing activity in excised cotyledons of different ages --- p.14 / Measurement of Ch1 accumulation in excised cotyledons after various pretreatment periods --- p.15 / Measurement of Ch1 accumulation in excised cotyledons under different light intensities and temperatures --- p.15 / Greening curve --- p.16 / Results and Discussion / Effect of seedling age on Ch1 accumulation --- p.16 / Effect of pretreatment period on Ch1 accumulation --- p.18 / Effects of light intensity and temperature on Ch1 accumulation --- p.18 / Effect of shaking (for oxygen replenishment) on Ch1 accumulation --- p.19 / Greening curve --- p.20 / Greening bioassay in excised cucumber cotyledons --- p.20 / Chapter 4. --- Regulation of Chlorophyll Accumulation in Excised Cucumber Cotyledons / Introduction --- p.27 / Materials and Methods / Materials --- p.28 / Seed germination --- p.28 / Harvesting and pretreatment --- p.28 / Illumination and Ch1 determination --- p.29 / Results / Effect of BA on Ch1 accumulation --- p.29 / Effect of Na2EGTA on Ch1 accumulation --- p.30 / "Effect of Na+, Ca2+ and K+ on Ch1 accumulation" --- p.32 / Effect of duration of pretreatment with Na+ ， Ca2+ and K+ on Ch1 accumulation --- p.34 / Effect of verapamil and Ca ionophore A23187 on Chl accumulation --- p.36 / Effect of TFP on Chl accumulation --- p.37 / Discussion / Effect of BA on Chl accumulation --- p.38 / "Effect of Na+, Ca2+ and K+ on Chl accumulation" --- p.39 / Demonstration of the involvement of Ca2+ in Chl accumulation --- p.43 / Chapter 5. --- The Calcium Effect on Benzyladenine-induced Stimulation of Chlorophyll Accumulation in Excised Cucumber Cotyledons / Introduction --- p.63 / Materials and Methods / Materials --- p.64 / Plant growth and treatment --- p.64 / Pretreatment experiment --- p.64 / Sequence experiment --- p.65 / Results / Pretreatment experiment --- p.65 / Sequence experiment --- p.66 / Discussion --- p.68 / Chapter 6. --- Regulation of 5-Aminolevulinic Acid and Chlorophyll Accumulation in Levulinic Acid-treated Cotyledons / Introduction --- p.80 / Materials and Methods / Materials --- p.81 / Plant growth and treatment --- p.81 / Chl determination and ALA assay --- p.82 / Measurement of ALA and Chl accumulation in LA-treated cotyledons --- p.83 / ALA accumulation curve --- p.83 / Measurement of Chl accumulation in 50 mM NaCl-treated cotyledons --- p.84 / "Measurement of ALA and Chl accumulation in BA-, cations-, Na2EGTA-, verapamil- and TFP-pretreated cotyledons" --- p.85 / Results / Concentrations effect of LA on ALA and Chl accumulation --- p.85 / ALA accumulation curve --- p.86 / Effect of 50 mM NaCl on Chl accumulation --- p.87 / Effect of BA on ALA and Chl accumulation in LA- treated cotyledons --- p.90 / "Effects of Na+, Ca2+ and K+ on ALA and Chl accumulation in LA-treated cotyledons" --- p.91 / "Effects of Na2EGTA, verapamil and TFP on ALA and Chl accumulation in LA-treated cotyledons" --- p.92 / Discussion / Measurement of ALA accumulation in LA-treated cotyledons --- p.93 / Effect of BA on ALA and Chl accumulation in LA-treated cotyledons --- p.96 / "Effects of Na+, Ca2+ and K+ on ALA and Chl accumulation in LA-treated cotyledons" --- p.98 / Demonstration of the involvement of Ca2+ in ALA accumulation --- p.99 / Chapter 7. --- Regulation of 5-Aminolevulinic Acid Accumulation in Isolated Developing Chloroplasts / Introduction --- p.123 / Materials and Methods / Materials --- p.124 / Plant materials --- p.124 / Chloroplast isolation --- p.125 / Incubation conditions --- p.126 / ALA assay --- p.127 / Measurement of ALA accumulation in LA-treated isolated developing chloroplasts --- p.128 / "Measurement of ALA accumulation in BA-, cations-, Na2EGTA-, verapamil- and TFP-treated isolated developing chloroplasts" --- p.128 / Results / Time course study of Chl accumulation in intact greening cotyledons of different ages --- p.129 / Measurement of ALA synthesizing activity in isolated developing chloroplasts incubated in the dark and light --- p.130 / Concentrations effect of LA on ALA accumulation in isolated developing chloroplasts --- p.130 / Effects of BA and the cations on ALA accumulation in isolated developing chloroplasts --- p.131 / "Effect of Na2EGTA, verapamil and TFP on ALA accumulation in isolated developing chloroplasts" --- p.132 / Discussion / Light regulation of ALA synthesizing activity in isolated developing chloroplasts --- p.132 / Regulation of ALA accumulation in isolated developing chloroplasts --- p.134 / Chapter 8. --- Conclusion --- p.147 / References --- p.151

Orientador: Antonio Ismael Inácio Cardoso / Banca: Noberto da Silva / Banca: Cyro Paulino da Costa / Abstract: The objective of this work was evaluate the inbreeding depression with successive generations of self-pollination in a cucumber "caipira" population (S0, S1, S2, S3; S4 e S5), obtained by crossing Safira x Hatem hybrids. Two experiments were accomplished: one to evaluate immature fruits production and another to analyze the mature fruits production, seed quality and yield. The experimental design of both experiments were randomized blocks, in the first with seven treatments (different generations of self pollination - S0 to S5 and the hybrid Safira), six replicates and five plants per plot and in the second the same seven treatments, four replicates and five plants per plot. In the first experiment (immature fruits) was number of leaves, length of the main stem, number and weight of fruits, total and commercial, number of nodes and vines percentage were evaluated. In the second experiment (mature fruit) the following traits were evaluated characteristic: seed number and weight per plant and per fruit and seed quality (germination test, first counted of seeds, index of germination speed and weight of 100 seeds). The averages were compared by the Tukey test (5%) and the evaluation of the inbreeding depression was made with regression analysis. In the experiment 1 smaller production of fruits was observed (total and commercial) starting from population S2, demonstrating possible vigor loss. The populations S0 and S1 were similar or superiors for the characteristics number of total fruits, total weight per plant and commercial weight per plant when compared to the hybrid Safira, demonstrating the potencial of this population to obtain a new cultivar or hybrid of the "caipira" type. The experiment two there was no statistical difference for all the appraised characteristics, showing that the inbreeding didn't affect the production and quality of the seeds in this population. / Mestre

Tez (Yüksek Lisans) - Süleyman Demirel Üniversitesi, Fen Bilimleri Enstitüsü, Bahçe Bitkileri Anabilim Dalı, 2007. / Kaynakça var.

The current research was designed to determine the effects of different compositions of a pectin-based emulsion coating on the quality indices and shelf life extension of mango and cucumber. The fruits were treated with pectin-based coating (coated) or kept as such (control), and stored under different temperatures and relative humidities. Samples of fruits were then tested periodically to note the changes in quality as determined by visual observation, weight loss, respiration rate, color, firmness, pH, titrable acidity (TA), total soluble solids (TSS), chlorophyll content, and decay. Coated fruits displayed retarded color development, higher TA, higher chlorophyll content, greater firmness, lower pH, and lower TSS. Loss in weight and CO 2 evolution were also reduced significantly. The results of this research suggested that pectin-based coating increased the shelf life of mango and cucumber more than 100% without perceptible losses in quality.

viii, 49 leaves : ill. ; 29 cm Notes Typescript Includes vita and abstract Thesis (M.S.)--University of Oregon, 1988 Bibliography: leaves 44-49 Another copy on microfilm is located in Archives