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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.
1

Studies on the Natural Products from the Taiwanese Sponge Ircinia formosana

Shih, Pei-hsiu 10 August 2007 (has links)
Six new compounds, irciformonins E~J (1~6), were isolated from CH2Cl2/MeOH extract of the sponge Ircinia formosana collected in Taiwan, toghther with two known compounds, irciformonins A and B. These compounds possess a linear C-22-sesterterpenoids type skeleton. The structures of all compounds were elucidated by spectroscopic analysis including 1D and 2D-NMR, optical rotation, IR, UV and high resolution mass spectra, as well as comparison with those in references. The stereochemistry of these compounds were determined by NOESY experiments, MM2 minimized energy, as well as comparison with those in references. The structures of all compounds possess a furan ring, a five membered lactone ring , and three methyl groups. Compounds 1 and 2 are geometric isomers. The differences between them are the substituents of the methoxyl group and the double bond. Compounds 1 and 2 possess substituents of the methoxyl group at C-10 and C-12 and have the double bond at C-11/C-12 and C-10/C-11. The differences between compounds 3 and 6 are the functional groups of the acetyl moeity and the double bond. Compound 3 has an acetyl group at C-12. Compounds 3 and 6 contain two double bonds at C-10/C-11 and C-11/C-12. Compound 4 has a cyclopentane between C-12~C-15 and a ketone group at C-10 while compound 5 possesses two acetyl groups at C-10 and C-15 positions.
2

The study of population genetics and conservation in Amentotaxus argotaenia complex

Ko, Ya-Zhu 31 July 2012 (has links)
Amentotaxus is an ancient lineage of gymnosperm genus. Based on the Tertiary fossil evidence, the ancient lineage was once widespread in the Northern Hemisphere but range contraction in Pleistocene and Holocene. Currently, the distributional range is restricted to southwestern China, Vietnam and Taiwan. In this study, the 15 polymorphic microsatellite primers were designed from A. formosana H. L. Li, and were used these primers for genetic research of species level and population level. In species level, we tested the transferability and polymorphism in four species, A. argotaenia (Hance) Pilger, A. formosana H. L. Li, A. poilanei (Ferr&#x00E9; & Rouane) D.K. Ferguson and A. yunnanensis H. L. Li were evaluated. In population level, we evaluate the genetic variation and genetic structure on two habitats including Mt. Chachayalaisham and Jinshueiying for the delimited of relevant genetic units and to establish useful conservation strategies. In species level, the 15 microsatellite primers had 100% successfully amplified fragments in these three species, also showing high polymorphisms (PIC=0.25-0.61). In population level, the genetic diversity analysis in the two population of A. formosana show that expected and observed heterozygosities were ranged from 0.52 to 0.60 and 0.28 to 0.36, respectively. In addition, 15 loci were deviated from Hardy-Weinberg equilibrium (P<0.001) and the inbreeding coefficient were displayed positive (FIS=0.48368; P <0.05), revealing the genetic fixation causing by inbreeding. The analysis of molecular variance (AMOVA) revealed that high genetic variation with population (83.85% and 52.39%), and also showed high levels of population differentiation (FST =0.10972-0.16155; P <0.05). IMa revealed low migration rate (1.13¡Ñ10-6-1.15¡Ñ10-4), also showed small effective population size (Cha: 77.36-1830.67; Jin: 21.41-506.67) and large ancestral population size (10496.8-248424.17), inferring the A. formosana undergo significant population declined. Using Bayesian clustering algorithms and Markov chain Monte Carlo (MCMC) iterations to distinct genetic units and make assignments in the programs SAMOVA¡BSTRUCTURE and INSTRUCT, the best clustering was occurred at K=2, and found 11 and 9 distinct genetic groups in Mt. Chachayalaisham and Jinshueiying based on GENELAND analysis, respectively. We correlated the distinct genetic units and the age structures to evaluate the individuals with unique genotype for seed source to maintain the maximum genetic diversity of A. formosana.
3

Škodlivost obalečů na ovocných dřevinách ve vybraných sadech na jižní Moravě

Fröhlich, Pavel January 2019 (has links)
During the 2018 season, five species of leaf rollers, which are harmful to fruit trees, were monitored (Cydia pomonella, C. funebrana, C. molesta, Enarmonia formosana and Pandemis heparana). The monitoring was carried out using pheromone traps in fruit orchards in south Moravia (Lednice, Starý Lískovec, Nosislav and Velké Bílovice) with varying wood preservation intensity. C. molesta reached the highest abundance, on average 241 individuals were caught in one pheromone trap, it was observed at all three study plots, in Lednice these species reached the highest abundance with 235 individuals. First imago was caught on the 27th of April, last imago on the 16th of September. One non-target species (Epiblema scutulana) was detected in this pheromone. C. funebrana was the second most abundant species, which was detected at both study plots,on average 148 individuals of C. funebrana were detected in one trap, the highest abundance was found in Lednice (224). First imago was detected on the 7th of May, last imago on the 26th of August. Five non-target species were caught in this pheromone, Gypsonoma sociana, G. nitidulana, G. aceriana, Eucosma fervidana and E. lacteana. Enarmonia formosana reached high abundance, caught at both study plots, 140 individuals were caught on average in one pheromone trap, the highest abundance was in Starý Lískovec with 199 of pieces. Cnephasia stephensiana, in particular, was caught as nontarget species, rarely Eucosma cumulana. Cydia pomonella was found at all three study areas, on average there were 84 individuals in the trap, 150 individuals in Starý Lískovec. First imago was caught on the 26th of April. There were no non-target moth species found in this pheromone trap. Pandemis heparana was registered at two study plots, 15 individuals were caught on average in one trap, the highest abundance was in Starý Lískovec with 19 individuals. P. heparana was not detected in Nosislav. First imago was caught on the 13th of May and the last on the 16th of September. Non-target species Noctua fimbriata and N. interjecta were caught in this pheromone.

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