published_or_final_version / Botany / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Botany / Doctoral / Doctor of Philosophy

Thesis (Ph. D.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 120-142).

Thesis (Ph. D.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.

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Exploiting the chemical ecology of an insect can unveil novel strategies for its pest management. Though much has been learned about the chemical ecology of Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), a major pest of solanaceous crops in the U.S., there has been little use of this knowledge in pest management. To better understand host plant selection by CPB, field and laboratory-choice experiments were conducted in Virginia. In laboratory studies, CPB preferred potato over both tomato and eggplant foliage and eggplant over tomato foliage. However, field studies using counts of live beetles on untreated paired plants and counts of dead beetles on insecticide-treated plants revealed no significant preference for potato over eggplant. Additional studies showed that the presence of adult male CPB on foliage greatly impacted host plant selection, with significantly more adults being attracted to eggplant with male beetles than any other treatment combination. Adult CPB have been shown to be attracted to (S)-3,7-dimethyl-2-oxo-oct-6-ene-1,3-diol [(S)-CPB I], a male-produced aggregation pheromone. Field studies were conducted to determine if the opposite enantiomer of the pheromone, (R)-CPB I had an effect on CPB in the field. Results revealed no differences in counts of all CPB life stages between untreated potato plots with and without rows inundated with (R)-CPB I lures. In addition, the relative attraction of CPB adults to various racemic forms of the (S)- and (R)-enantiomers was also investigated and showed that racemic blends that were less than 97%(S) were not attractive to CPB adults. Combinations of the (S)-CPB I pheromone with synthetic plant volatiles consisting of (Z)-3-hexenyl acetate, (+)-linalool, and methyl salicylate were investigated in a trap crop strategy in potatoes, but failed to reduce CPB numbers in untreated middle rows of potatoes. Combinations of the (S)-CPB I pheromone with synthetic plant volatiles were also used in a novel CPB trap designed to catch colonizing adults in the field. Although the traps caught CPB adults, no differences were observed in traps baited with and without the attractant. Metaflumizone, a novel semicarbazone insecticide, was recently shown to be highly efficacious on CPB. Laboratory studies found the combination of metaflumizone and a low concentration (0.39 ppm) of the pyrethroid esfenvalerate was slightly synergistic on CPB adults and early (1st-2nd) instar larvae. Field trials combining a low rate of esfenvalerate and metaflumizone at one tenth the field rate controlled beetles as well as the full rate of metaflumizone. / Ph. D.

Introdução: O extrato seco de Solanum melongena (berinjela) vem sendo utilizado pela população como um tratamento alternativo para dislipidemia. Ela é um vegetal rico em flavonóides que são antioxidantes polifenólicos encontrados nos alimentos. Estudos demonstram relação inversa entre o consumo de alimentos ricos em flavonóides e a mortalidade por doença arterial coronariana. O objetivo deste estudo foi avaliar o efeito da administração de cápsulas de extrato de berinjela no perfil lipídico de indivíduos saudáveis após um teste de sobrecarga lipídica via oral . Métodos: Após consentimento informado 58 voluntários saudáveis foram randomizados para receber cápsulas contendo 450 mg extrato seco de berinjela ou placebo. As cápsulas de berinjela ou placebo foram administradas na quantidade de duas cápsulas duas vezes ao dia durante 14 dias. No 14º dia os voluntários foram submetidos a um teste de sobrecarga lipídica, logo após a ingestão de 900 mg de extrato de berinjela ou placebo conforme randomização anterior. A análise nutricional da refeição continha 361 kcal, 22,5 g de gorduras totais, sendo destas 14,5g de gordura saturada e 251mg de colesterol. O perfil lipidico foi aferido em jejum nos dias 0 e 14 e neste último dia aferido em jejum e 2 horas após a sobrecarga lipidica. Resultados: Os níveis de trigliderídeos, expressos em mediana (amplitude interquartílica), encontrados nos voluntários do grupo berinjela foram 69mg/dl (51 - 102), 69 mg/dl (56 - 94) e 92 (64 - 120), antes do tratamento, no 14º dia pré e pós prandial, respectivamente. No grupo placebo os resultados foram 92mg/dl (77 - 128), 79 (60 - 108) e 98 (73 - 142), respectivamente. Não houve interação estatisticamente significativa entre tempo e grupo quanto ao nível de triglicerídeos (P=0,208). Também não foram encontradas diferenças nos valores de colesterol total (P=0,973), HDL colesterol (P=0,059) e LDL colesterol (P=0,611). Conclusão: Nossos resultados demonstram que a utilização de cápsulas de extrato seco de S. Melongena por 14 dias não produziu nenhum efeito no perfil lipidico em jejum e pós-prandial em indivíduos normais. / Introduction: Dry Solanum melongena (eggplant) extract is being used by the population as an alternative treatment for dyslipidemia. It is a vegetable rich in flavonoids, which are polyphenol anti-oxidants found in foods. Studies reveal an inverse relationship between the consumption of foods rich in flavonoids and mortality from coronary artery disease. The objective of this study was to assess the effect of administering eggplant extract capsules on the lipid profile of healthy individuals after an oral lipid overload test. Methods: After informed consent, 59 healthy volunteers were randomized to take capsules containing 450 mg of dry eggplant extract or placebo. The eggplant or placebo capsules were administered in quantities of two capsules, twice a day, for 14 days. On the 14th day, the volunteers were submitted to a lipid overload test immediately after ingesting 900 mg of eggplant extract or placebo as per prior randomization. The nutritional analysis of the meal contained 361 kcal, 22.5 g of total fat, 14.5 g of which was saturated and 251mg of cholesterol. The lipid profile was checked during fasting on days 0 and 14 and on this last day it was checked during fasting and after a lipid overload. Results: Triglyceride levels, expressed as median (interquartile range), found in eggplant group volunteers were 69mg/dl (51 -102), 69 mg/dl (56 - 94) and 92 (64 - 120), before treatment, on the 14th day pre- and postprandial, respectively. In the placebo group, the results were 92mg/dl (77 - 128), 79 (60 - 108) and 98 (73 - 142), respectively. There was no statistically significant interaction between the time and the group as to triglyceride levels (P=0.208). No difference was found in total cholesterol (P=0.973), HDL cholesterol (P=0.059) and LDL cholesterol (P=0.611) levels either. Conclusion: Our results reveal that the use of dry S. Melongena extract capsules for 14 days did not produce any effect on the lipid profile during fasting and postprandial in normal individuals.

Introdução: O extrato seco de Solanum melongena (berinjela) vem sendo utilizado pela população como um tratamento alternativo para dislipidemia. Ela é um vegetal rico em flavonóides que são antioxidantes polifenólicos encontrados nos alimentos. Estudos demonstram relação inversa entre o consumo de alimentos ricos em flavonóides e a mortalidade por doença arterial coronariana. O objetivo deste estudo foi avaliar o efeito da administração de cápsulas de extrato de berinjela no perfil lipídico de indivíduos saudáveis após um teste de sobrecarga lipídica via oral . Métodos: Após consentimento informado 58 voluntários saudáveis foram randomizados para receber cápsulas contendo 450 mg extrato seco de berinjela ou placebo. As cápsulas de berinjela ou placebo foram administradas na quantidade de duas cápsulas duas vezes ao dia durante 14 dias. No 14º dia os voluntários foram submetidos a um teste de sobrecarga lipídica, logo após a ingestão de 900 mg de extrato de berinjela ou placebo conforme randomização anterior. A análise nutricional da refeição continha 361 kcal, 22,5 g de gorduras totais, sendo destas 14,5g de gordura saturada e 251mg de colesterol. O perfil lipidico foi aferido em jejum nos dias 0 e 14 e neste último dia aferido em jejum e 2 horas após a sobrecarga lipidica. Resultados: Os níveis de trigliderídeos, expressos em mediana (amplitude interquartílica), encontrados nos voluntários do grupo berinjela foram 69mg/dl (51 - 102), 69 mg/dl (56 - 94) e 92 (64 - 120), antes do tratamento, no 14º dia pré e pós prandial, respectivamente. No grupo placebo os resultados foram 92mg/dl (77 - 128), 79 (60 - 108) e 98 (73 - 142), respectivamente. Não houve interação estatisticamente significativa entre tempo e grupo quanto ao nível de triglicerídeos (P=0,208). Também não foram encontradas diferenças nos valores de colesterol total (P=0,973), HDL colesterol (P=0,059) e LDL colesterol (P=0,611). Conclusão: Nossos resultados demonstram que a utilização de cápsulas de extrato seco de S. Melongena por 14 dias não produziu nenhum efeito no perfil lipidico em jejum e pós-prandial em indivíduos normais. / Introduction: Dry Solanum melongena (eggplant) extract is being used by the population as an alternative treatment for dyslipidemia. It is a vegetable rich in flavonoids, which are polyphenol anti-oxidants found in foods. Studies reveal an inverse relationship between the consumption of foods rich in flavonoids and mortality from coronary artery disease. The objective of this study was to assess the effect of administering eggplant extract capsules on the lipid profile of healthy individuals after an oral lipid overload test. Methods: After informed consent, 59 healthy volunteers were randomized to take capsules containing 450 mg of dry eggplant extract or placebo. The eggplant or placebo capsules were administered in quantities of two capsules, twice a day, for 14 days. On the 14th day, the volunteers were submitted to a lipid overload test immediately after ingesting 900 mg of eggplant extract or placebo as per prior randomization. The nutritional analysis of the meal contained 361 kcal, 22.5 g of total fat, 14.5 g of which was saturated and 251mg of cholesterol. The lipid profile was checked during fasting on days 0 and 14 and on this last day it was checked during fasting and after a lipid overload. Results: Triglyceride levels, expressed as median (interquartile range), found in eggplant group volunteers were 69mg/dl (51 -102), 69 mg/dl (56 - 94) and 92 (64 - 120), before treatment, on the 14th day pre- and postprandial, respectively. In the placebo group, the results were 92mg/dl (77 - 128), 79 (60 - 108) and 98 (73 - 142), respectively. There was no statistically significant interaction between the time and the group as to triglyceride levels (P=0.208). No difference was found in total cholesterol (P=0.973), HDL cholesterol (P=0.059) and LDL cholesterol (P=0.611) levels either. Conclusion: Our results reveal that the use of dry S. Melongena extract capsules for 14 days did not produce any effect on the lipid profile during fasting and postprandial in normal individuals.

Introdução: O extrato seco de Solanum melongena (berinjela) vem sendo utilizado pela população como um tratamento alternativo para dislipidemia. Ela é um vegetal rico em flavonóides que são antioxidantes polifenólicos encontrados nos alimentos. Estudos demonstram relação inversa entre o consumo de alimentos ricos em flavonóides e a mortalidade por doença arterial coronariana. O objetivo deste estudo foi avaliar o efeito da administração de cápsulas de extrato de berinjela no perfil lipídico de indivíduos saudáveis após um teste de sobrecarga lipídica via oral . Métodos: Após consentimento informado 58 voluntários saudáveis foram randomizados para receber cápsulas contendo 450 mg extrato seco de berinjela ou placebo. As cápsulas de berinjela ou placebo foram administradas na quantidade de duas cápsulas duas vezes ao dia durante 14 dias. No 14º dia os voluntários foram submetidos a um teste de sobrecarga lipídica, logo após a ingestão de 900 mg de extrato de berinjela ou placebo conforme randomização anterior. A análise nutricional da refeição continha 361 kcal, 22,5 g de gorduras totais, sendo destas 14,5g de gordura saturada e 251mg de colesterol. O perfil lipidico foi aferido em jejum nos dias 0 e 14 e neste último dia aferido em jejum e 2 horas após a sobrecarga lipidica. Resultados: Os níveis de trigliderídeos, expressos em mediana (amplitude interquartílica), encontrados nos voluntários do grupo berinjela foram 69mg/dl (51 - 102), 69 mg/dl (56 - 94) e 92 (64 - 120), antes do tratamento, no 14º dia pré e pós prandial, respectivamente. No grupo placebo os resultados foram 92mg/dl (77 - 128), 79 (60 - 108) e 98 (73 - 142), respectivamente. Não houve interação estatisticamente significativa entre tempo e grupo quanto ao nível de triglicerídeos (P=0,208). Também não foram encontradas diferenças nos valores de colesterol total (P=0,973), HDL colesterol (P=0,059) e LDL colesterol (P=0,611). Conclusão: Nossos resultados demonstram que a utilização de cápsulas de extrato seco de S. Melongena por 14 dias não produziu nenhum efeito no perfil lipidico em jejum e pós-prandial em indivíduos normais. / Introduction: Dry Solanum melongena (eggplant) extract is being used by the population as an alternative treatment for dyslipidemia. It is a vegetable rich in flavonoids, which are polyphenol anti-oxidants found in foods. Studies reveal an inverse relationship between the consumption of foods rich in flavonoids and mortality from coronary artery disease. The objective of this study was to assess the effect of administering eggplant extract capsules on the lipid profile of healthy individuals after an oral lipid overload test. Methods: After informed consent, 59 healthy volunteers were randomized to take capsules containing 450 mg of dry eggplant extract or placebo. The eggplant or placebo capsules were administered in quantities of two capsules, twice a day, for 14 days. On the 14th day, the volunteers were submitted to a lipid overload test immediately after ingesting 900 mg of eggplant extract or placebo as per prior randomization. The nutritional analysis of the meal contained 361 kcal, 22.5 g of total fat, 14.5 g of which was saturated and 251mg of cholesterol. The lipid profile was checked during fasting on days 0 and 14 and on this last day it was checked during fasting and after a lipid overload. Results: Triglyceride levels, expressed as median (interquartile range), found in eggplant group volunteers were 69mg/dl (51 -102), 69 mg/dl (56 - 94) and 92 (64 - 120), before treatment, on the 14th day pre- and postprandial, respectively. In the placebo group, the results were 92mg/dl (77 - 128), 79 (60 - 108) and 98 (73 - 142), respectively. There was no statistically significant interaction between the time and the group as to triglyceride levels (P=0.208). No difference was found in total cholesterol (P=0.973), HDL cholesterol (P=0.059) and LDL cholesterol (P=0.611) levels either. Conclusion: Our results reveal that the use of dry S. Melongena extract capsules for 14 days did not produce any effect on the lipid profile during fasting and postprandial in normal individuals.

M.S.