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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

Identification, molecular cloning and characterisation of homospermidine synthase and deoxyhypusine synthase from Phalaenopsis and Crotalaria species /

Nurhayati, Niknik. January 2004 (has links) (PDF)
Techn. Univ., Diss.--Braunschweig, 2004.
2

The effects of complex additives and growth regulators on the growth and clonal propagation of Phalaenopsis orchids

Ackerman, Rodney Rex January 1988 (has links)
The goal of this study was two fold, the first was to determine the effect of different basal medium formulationsand medium supplements (complex additives and growth hormones) on the development and growth rate of Phalaenopsis orchids, while the second goal was to find or develop an efficent method for the clonal propagation of Phalaenopsis orchids.MethodsThe first part of this study was further subdivided in to several phases; the first of these involved a comparative study of the germination of Phalaenopsis ovules on six different basal medium formulations and seven different sets of medium supplements. The second phase involved a comparative study of the development of Phalaenopsis protocorms on six different basal medium formulations and ninteen different sets of medium supplements. The third phase involved a comparative study of the growth of Phalaenopsis seedlings on six different basal medium formulations and twelve sets of medium supplements. The forth and final phase involved a comparative study of the development and growth of Phalaenopsis protocorms and seedlings on media containing varing concentrations and combinations of auxins and cytokinins. The second part of this study involved a comparative study designed-to determine the suitability of several sizes of axillary buds and plantlets for the clonal propagation of Phalaenopsis orchids and the modification of several procedures in an attempt to determine suitable explant material and procedures for the commercial clonal propagation of Phalaenopsis orchids.Results and DiscussionResults of this study indicated that of the basal medium formulations and medium supplements tested Modified Heller's salt base medium and to a lesser extent Modified Vacin and Went salt base medium supplemented with vitamin formulation 1 and Bactopeptone yielded the highest percent germination and development up to the seedling stage. At the seedling stage the growth rate of seedlings grown on media supplemented with banana homogenate nearly doubled the growth rate of the seedlings grown on all of the other medium supplementstested.Results of the second part of this study indicated that by modifying the procedures of Bouriquet, Broly, and Legrand (1982) the proliferation rate (shoots per plantlet) could be increased by a factor of two to eight. This can be translated into an increase from two to five shoots per plantlet per six weeks to an increase of eight shoots per plantlet per six weeks with a minimal mortality rate. With further modification of the procedure of Bouriquet, Broly, and Legrand (1982), other results indicated that it may be possible to increase to forty the number of shoots per plantlet produced per six week period. / Department of Biology
3

Changes in gibberellin levels in the flowering shoot of Phalaenopsis hybrida under high temperature conditions when flower development is blocked

Su, Wei-Ren 25 August 2003 (has links)
The ability of exogenous gibberellin (GA) A3 to substitute for low temperatures in inducing flowering in Phalaenopsis hybrida under high temperatures suggests a similar role for endogenous GAs in normal (low temperature) development of the inflorescence and floral buds. Changes in endogenous GAs in shoot-tips (about 2.0 cm long) were examined when potentially flowering shoot was 2-3 cm and 7-10 cm long, respectively. Treatments included warm control (30/25 ¢J day/night, non-flowering), GA3-treated (30/25 ¢J day/night, flowering) and cool-induced (25/20 ¢J day/night, flowering) plants. GA3 at 0.5 £gg•shoot-1 was injected into the cavity of the second visible bud scale below the flowering shoot apex. The contents of the tips of potentially flowering shoot of GA1, GA20, GA19 and GA53 tended to be highest in cool-induced plants, intermediate in GA3-treated plants, and lowest in the warm controls (non-flowering). Tips of potentially flowering shoots in warm controls also contained higher GA8 relative to GA3-treated and cool-induced plants. Tips of potentially flowering shoots (2-3 cm in length with no flower primordium), contained low levels of GAs than older 7-10 cm long flowering shoot (with flower primordium) under cool-inductive conditions. These results suggest that continued inflorescence development and flower bud initiation are closely associated with increases in endogenous GAs, even in GA3-treated plants. They also suggest that a more rapid biosynthetic flow-through from GA19¡÷GA20¡÷GA1¡÷GA8 leaving reduced levels of GA1 may be involved in the inhibition of flowering and shoot elongation seen in warm (30/25 ¢J day/night) control plants. A reduced conversion of ¡§active¡¨ GA1 to inactive GA8 may thus be required for successful floral initiation and development whether induced by cool temperature or by applied GA3. These results imply that the high temperature inhibitory effect on flowering is mediated through its effect on lowering the level of endogenous GA1 and its precursors.
4

Polyamines affect early floral initiation in Doritis pulcherrima and Phalaenopsis

Wang, Kuo-Cheng 11 July 2002 (has links)
Polyamine titer in the leaves of the self-seedlings of Doritis pulcherrima Lindley¡]cv. S84-3352¡^under short-day ( SD, 9 hours of light period ) and long-day ( LD, 16 hours of light period ) exposures were determined. A significant reduction in acid insoluble spermidine levels occurred in D. pulcherrima leaves after 30 days of SD compared to the LD exposures. After 30 days of SD there was a transient decrease in acid insoluble spermidine and an increase in acid insoluble spermine in the leaves. When the flowering shoot reached 7 -10 cm long ( with flower primordia in SD ), free cadaverine, acid insoluble putrescine, and spermine levels were higher than those in 2-3 cm flowering shoot ( with no flower primordium derived from SD ) These results suggest that polyamines are implicated differently during photoperiodic flower induction and flower devlopment in D. pulcherrima.
5

Molekularbiologische und immunologische Untersuchungen zur gewebe- und zellspezifischen Lokalisation der Homospermidin-Synthase, des Eingangsenzyms der Pyrrolizidin-Alkaloid-Biosynthese, in Eupatorium-cannabinum- (Asteraceae) und Phalaenopsis-Species

Anke, Sven. Unknown Date (has links) (PDF)
Techn. Universiẗat, Diss., 2004--Braunschweig.
6

Molecular Phylogeny, Biogeography, and Evolutionary Trends of the genus Phalaenopsis (Orchidaceae)

Tsai, Chi-Chu 14 February 2004 (has links)
Species of Phalaenopsis Blume (Orchidaceae) are found throughout tropical Asia, namely South China, Indochina, India, Southeast Asia, and Australia. This genus is comprised of approximately 66 species according to the latest classification. Most of them possess commercial value. Thousands of Phalaenopsis cultivars have been grown for commercial goals. Although this orchid is very beautiful and popular throughout the world, studies on the molecular systematics and phylogenetic relationships among these orchids are still deficient. Phylogenetic trees inferred from the internal transcribed spacers 1 and 2 (ITS1+ITS2) region of nuclear ribosomal DNA (nrDNA) and chloroplast DNAs (cpDNAs), including the intron of trnL, the IGS of trnL-trnF, and the IGS of atpB-rbcL, were used to clarify the phylogenetics and evolutionary trends of the genus Phalaenopsis (Orchidaceae). Molecular data are provided to clarify the latest systematics of the genus Phalaenopsis as suggested by Christenson (2001). He treated the genera of Doritis and Kingidium as synonyms of the genus Phalaenopsis and divided it into the five subgenera of Proboscidioides, Aphyllae, Parishianae, Polychilos, and Phalaenopsis. The results concurred that the genera Doritis and Kingidium should be treated as synonyms of the genus Phalaenopsis as suggested by Christenson (2001). The subgenera of Aphyllae and Parishianae were both shown to be monophyletic groups, and to be highly clustered with the subgenus Proboscidioides and two sections (including sections Esmeralda and Deliciosae) of the subgenus Phalaenopsis, which have the same morphological characters of four pollinia as well as similar biogeographies. Furthermore, neither the subgenus Phalaenopsis nor Polychilos was found to be a monophyletic group in this study. In addition, the phylogenetic tree indicates that Phalaenopsis is monophyletic and does not support the existing subgeneric and sectional classification. The phylogenetic tree of the genus Phalaenopsis is basically congruent with the geographical distributions of this genus. Based on the tree, two major clades were separated within the genus Phalaenopsis. The first clade, having four pollinia, included sections Proboscidiodes, Parishianae, and Esmeralda, of which are distributed in South China, India, and Indochina. The second clade, bearing two pollinia, included the sections Phalaenopsis, Polychilos, and Fuscatae, of which are distributed in Malaysia, Indonesia, and the Philippines. In addition, the biogeography of the genus Phalaenopsis is congruent with the historical geology of the distribution regions of this genus as well. According to molecular evidences, biogeography, historical geology, and the evolutionary trend of pollinia number of orchid, evolutionary trends of the genus Phalaenopsis were deduced. The subgenus Aphyllae was suggested to be the origin of Phalaenopsis and South China was suggested to be the origin center of Phalaenopsis. In addition, there were two dispersal pathways of Phalaenopsis from the origin center to Southeast Asia. In one pathway, Phalaenopsis species dispersed from South China to Southeast Asia, in particular the Philippines, using Indochina, older lands of the Philippines (Mindoro, Palawan, Zamboanga, etc.) as steppingstones, from which the subgenus Phalaenopsis developed. In the other pathway, Phalaenopsis species dispersed from South China to Southeast Asia, in particular Indonesia and Malaysia, using the Malay Peninsula as a steppingstone, from which the subgenus Polychilos developed. Furthermore, molecular data and geological dating were used to estimate the substitution rates of DNA from the genus Phalaenopsis based on the hypothesis of the molecular clock. The substitution rates of both ITS and cpDNA data from the genus Phalaenopsis were 2.4~4.7 x 10-9 and 3.9~7.8 x 10¡V10 substitutions/site/year, respectively. The substitution rates of ITS data of the genus Phalaenopsis are approximately six times those of cpDNA. Based on the substitution rates, the divergence time among most of the P. lueddemanniana complex was estimated to have been during the Pleistocene. The section Deliciosae separated from the section Stauroglottis at 21~10.5 Mya. Furthermore, the phylogenetics of the close species of Phalaenopsis will be evaluated based on molecular data, involving three groups of close Phalaenopsis species, namely the P. amabilis complex, P. sumatrana complex, and P. violacea complex. For the first complex, the internal transcribed spacer 1 and 2 (ITS1+ITS2) regions of nuclear ribosomal DNA (nrDNA) were applied to evaluate the phylogenetics of the P. amabilis complex, namely P. amabilis, P. amabilis subsp. moluccana, P. amabilis subsp. rosenstromii, P. aphrodite, P. aphrodite subsp. formosana, and P. sanderiana. Based on molecular data, each of species/subspecies from the P. amabilis complex with the exception of P. aphrodite and its subspecies could be separated from each other. Phalaenopsis aphrodite from different locations and its subspecies could not be separated from each other, but all of them were separable from different populations/subspecies of P. amabilis. In addition, P. sanderiana was nested within both P. amabilis and its subspecies. These results do not support P. sanderiana being treated as a separate species from P. amabilis. In addition, I suggest that P. aphrodite is the origin of the P. amabilis complex and originated in the Philippines. Phalaenopsis amabilis and P. sanderiana descended from P. aphrodite (or its ancestor). Based on the phylogenetic tree, evolutionary trends of the P. amabilis complex were suggested. Within evolutionary trends of P. amabilis complex, two different lineages with different dispersal pathways were suggested. First, P. aphrodite, dispersed into Palawan and evolved to be P. amabilis, thereafter further dispersing into Borneo and Sumatra. Second, P. aphrodite dispersed into southern Mindanao and evolved into P. sanderiana, thereafter further dispersing into Sulawesi and New Guinea, from which P. amabilis subsp. moluccana and P. amabilis subsp. rosenstromii developed, respectively. For the second complex, the phylogenetic relationship of the P. sumatrana complex, namely P. sumatrana, P. corningiana, and P. zebrina, was detected based on the ITS1 and ITS2 regions of nrDNA, the intron of trnL, and the IGS of atpB-rbcL of cpDNA. The P. sumatrana complex includes the two species of P. sumatrana and P. corningiana, as well as a problem species, P. zebrina, according to the concepts of Sweet (1980) and Christenson (2001). Based on the phylogenetic tree inferred from the ITS sequence, accessions of P. sumatrana cannot be separated from those of P. corningiana. Furthermore, accessions of P. zebrina can be separated from those of both P. sumatrana and P. corningiana. In addition, analyses of both sequences of the trnL intron and atpB-rbcL IGS of cpDNA apparently cannot discriminate among these three species of the P. sumatrana complex. Based on the molecular data of this study, plants of P. zebrina might be treated as a separate species from both P. sumatrana and P. corningiana. In the evolutionary trend of the P. sumatrana complex, plants of P. zebrina were deduced to be the relative origin group of the P. sumatrana complex based on the phylogenetic tree and biogeography. In addition, plants of both P. sumatrana and P. corningiana might have descended from plants of P. zebrina. For the third complex, the phylogenetic trees inferred from the internal transcribed spacer 1 and 2 (ITS1+ITS2) regions of nuclear ribosomal DNA (nrDNA), the intron of trnL, and the intergenic spacer of atpB-rbcL of chloroplast DNA (cpDNA) were used to clarify the phylogenetic relationships of the P. violacea complex. The complex includes the two species of P. violacea and P. bellina, according to the concept of Christenson (2001). Based on the phylogenetic tree inferred from the ITS sequence, P. bellina could not be separated from most populations from P. violacea with the exception of the population distributed on Mentawai Is., Indonesia. In addition, analyses of both the intron of trnL and the IGS of atpB-rbcL of cpDNA apparently could not discriminate among the three species of the P. sumatrana complex. Based on the morphological characters, P. violacea from Mentawai Is. bears a long floral rachis and was separable from the other groups of the P. violacea complex. Therefore, the results in this study have a trend to treat the population of Mentawai Is. of the P. violacea complex as a separate species from P. violacea. In the evolutionary trend of the P. violacea complex, Mentawai plants of this complex might be descended from those of Sumatra/the Malay Peninsula according to the phylogenetic analysis and biogeography.
7

Gametophytic Selection for Thermotolerance in Phalaenopsis

Blischak, Leslie Anne 18 August 2005 (has links)
Gametophytic selection was examined as a breeding tool in developing Phalaenopsis hybrids that are more cool or warm temperature tolerant. Two hybrid Phalaenopsis, P. (Taisoco Windian à Sogo Sogo Yukidian) by P. hybrid unknown, were reciprocally cross-pollinated and exposed to 14°C/9°C for 7 days as a cold pollination treatment. Plants were pollinated again and exposed to 30°C/25°C for 3 days for the warm pollination treatment. Each cultivar was placed in either of two growth chambers during the pollination treatments and exposed to the selected temperatures, an 11-h photoperiod with an irradiance of 180 Mmol·m-2·s-1 and a relative humidity of 70%. The plants were returned to the greenhouse after pollination and the green capsules were collected after 150 days. Seeds obtained from these treatments were surface-sterilized and equal volumes were placed on Phytamax® medium. Evaluation of protocorm development was done after 73 days on a thermogradient table ranging from 10 to 30ºC. For the first family for which reciprocal crosses were available, the number of protocorms per plate ranged from 0 in the coldest treatments to 290 at 28°C. For cold pollinated seeds, protocorm development was optimum at 22 and 28°C (means of 290 and 250 protocorms per plate, respectively) whereas the greatest protocorm development for warm pollinated seeds occurred at 20°C (103 protocorms per plate). Of the 1471 total protocorms obtained 1095 were from cold pollinations, whereas 376 were from the warm pollinations. Protocorms were evaluated for leaf and root formation 125 days after initial plating. Transfer to warm or cold incubators occurred as protocorms developed leaves and roots. Seedlings were finally transferred to dried sphagnum and placed in growth chambers set to original pollination temperatures. One year after initial plating seedlings were evaluated on the following criteria: wet weight, number of leaves, leaf area, number of roots, and root length. The pollination treatment significantly affected the number of roots per seedling whereas germination temperature during germination significantly affected the weight (g). Weight of the seedlings, number of roots and the average root length were significantly affected by the interaction between pollination treatment and germination temperature. The weight, number of leaves, and average root length were significantly affected by the interaction between pollination treatment and incubator/growth chamber. These differences indicated that seedlings derived from warm pollination were more vigorous under warm growing conditions and those derived from cold pollination were more vigorous under cold growing conditions. The significance of the interaction between pollination treatment and incubator/growth chamber indicates that gametophytic selection for thermotolerance in Phalaenopsis can be successfully used as a plant breeding tool. Additional replication is required to confirm the greater germinability of seed derived from pollination occurring over a greater range of temperatures. / Master of Science
8

In vitro conservation of selected endangered plant species indigenous to the Cape Floristic Region, South Africa

Mosime, Bonolo January 2016 (has links)
Thesis (MTech (Horticulture))--Cape Peninsula University of Technology, 2016. / This study focused on optimising four types of in-vitro conservation methods, namely: 1), micropropagation, 2) in-vitro slow growth, 3) seed germination and 4) cryopreservation for selected endangered plant species indigenous to the Cape Floristic Region. It is one of the targets set by United Nations millennium development goals, to integrate different conservation measures in order to preserve plant diversity and mitigate losses of genetic diversity. Therefore this study uses Phalaenopsis hybrids as a trial species that can be studied for the conservation of endangered Disa and Eulophia species through micropropagation and in vitro slow growth. Also conservation attempts on Leucadendron and Mimetes species that occur in the Cape Floristic Region were attemted to increase population densities by increasing germination percentages using smoke. Furthermore, the study attempted to store seeds by assessing different cooling rates for optimising cryopreservation measures for effective conservation. The use of tissue culture to increase propagules especially critically endangered species in South African has proven to be feasible. For the trial hybrids, shoot and protocorm explants of Phalaenopsis Psychosis Pink X P. No. 1; P. Large white X P. Large pink; P. No. 1 X P. Large pink; P. Mini pink X Brighton belle; and the P. aphrodite formed clusters of protocorms and shoots when cultured on ½ strength MS media supplemented with 10, 20 and 30gL-1 banana extract or ½ strength Murashige and Skoog, (1962) (MS) media supplemented with peptone. Continuous protocorms formation could therefore be obtained by culturing endangered Disa and Eulophia shoots and protocorms on banana containing media. Plantlet conversion from somatic embryos produced on 10gL-1 banana extract enriched media was successfully achieved on ½ strength MS supplemented with 20gL-1 sucrose and no plant growth regulators in the medium. However, optimum rooting was achieved on ½ strength MS supplemented with 30gL-1 of banana extract and this medium yielded the highest survival percentages for plantlet acclimatisation. Furthermore, ½ strength MS supplemented with 1gL-1 of peptone served as a stimulant for shoot development and protocorm formation. When coupled with banana extract at all stages of development, regeneration and rooting were enhanced.
9

Research on Taiwanese Phalaenopsis Industry¡¦s Business Strategy ¡V A Case of Firm A.

Lu, Hsuan-chin 24 July 2008 (has links)
Combined with farmers¡¦ innovations and modern biotechnological discoveries since 20 years ago, Taiwan has become a critical exporter of phalaenopsis. In 2004, Council of Agriculture set phalaenopsis, mango, tea and Taiwan porgy as the four crucial exporting agricultural products. Yet it was when the total value of phalaenopsis exported went down, a significant siren indicating that the phalaenopsis growing industry is facing severe environments. This research discussed business model, related practice and competition advantages of the case company in the phalaenopsis growing industry, and compare them with researchers¡¦ papers including Dr. Peng Tso-kuei¡¦s discoveries of the trends of management and competition. Results are: I. The case company carried out its idea, spirit and objectives in their operation, II. Differentiation strategy is the main source of the case company¡¦s competitive advantage, and III. The management and competition situations of phalaenopsis growing industry changes fast, firms should adjust practices to adjust themselves to the market.
10

The determinants of Phalaenopsis orchid export from Taiwan to China.

Wu, Pei-Yu 02 July 2012 (has links)
This paper is based on international trade between Taiwan and China intently. This purpose of this paper is to explore economic factors on the volume of Phalaenopsis orchid export from Taiwan to China from 1998 to 2011 . This paper will firstly set four influence variables, the previous export, the China's GDP, the exchange rate and the tariff . Then, this paper will exam those variables by using Unit Root test and the Vector Autoregressive (VAR) method in an empirical analysis. After the examination by Unit Root test, the result shows that all the variables appear to be stationary in the first difference. Furthermore, in Chow test, the empirical results indicate that no structural change occurred before and after the first phase of tariff reduction under ECFA. In co-integration test, those variables are co-integrated. In VAR model, China¡¦s GDP, the exchange rate, and the tariff have impact on the volume of the imports from Taiwan to China in different degrees as well.

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