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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

RegeneraÃÃo "in vitro", estudos histolÃgicos e transformaÃÃo genÃtica da momoneira (Ricinus communis) / "In vitro" regeneration, histologycal studies and genetic transformation of castor-bean (Ricinus communis)

Emanoella Lima Soares 20 February 2009 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A mamoneira (Ricinus communis) à uma oleaginosa com valor econÃmico considerÃvel devido à composiÃÃo do Ãleo de suas sementes. No entanto, hà algumas limitaÃÃes no seu uso para alimentaÃÃo humana e animal devido à presenÃa de proteÃnas tÃxicas e alergÃnicas, as quais podem ser solucionadas ou minimizadas atravÃs da engenharia genÃtica. Contudo, essa cultura à recalcitrante para tÃcnicas de cultura de tecidos limitando a geraÃÃo de plantas transformadas e os protocolos existentes nÃo sÃo bem estabelecidos. O objetivo desse trabalho foi avaliar a aplicabilidade de um protocolo de regeneraÃÃo existente na literatura à cultivar Nordestina; determinar a via de regeneraÃÃo e avaliar, atravÃs de tÃcnicas histoquÃmicas, as cÃlulas transformadas por biobalÃstica em torno do meristema. Para este propÃsito, eixos embrionÃrios foram cultivados em meio Murashig and Skoog (MS) suplementado com concentraÃÃes crescentes de tidiazuron (TDZ) (0,1; 0,5; 1,0; 2,0; 5,0 e 10,0 mg.L-1). Observou-se que entre as concentraÃÃes de TDZ avaliadas a que apresentou a melhor resposta foi 0,1 mg.L-1, apresentando, em mÃdia, apÃs 56 dias de incubaÃÃo,7,42 partes aÃreas por explante. Ãcido giberÃlico (0,1 mg.L-1) e Ãcido-indol-3 butÃrico (1,0 mg.L-1) foram utilizados na tentativa de alongar e promover o enraizamento, respectivamente, das partes aÃreas obtidas, contudo, nas concentraÃÃes utilizadas, nÃo evidenciou-se nenhum efeito com estes reguladores de crescimento. AnÃlises histolÃgicas revelaram que as partes aÃreas foram formadas de meristemas prÃ-existentes e neo-formados indicando organogÃnese direta. Observaram-se cÃlulas transformadas pelo menos atà a segunda camada celular. AnÃlises da expressÃo estÃvel do gene gus mostraram expressÃo do mesmo, 19 dias apÃs o bombardeamento. Nas anÃlises histolÃgicas foram observadas cÃlulas transformadas em divisÃo. Como conclusÃo a cultivar Nordestina foi capaz de formar mÃltiplas partes aÃreas em meio contendo TDZ e este protocolo de regeneraÃÃo foi compatÃvel com um protocolo de transformaÃÃo por biobalÃstica / Castor bean (Ricinus communis) is an oilseed crop with considerable economic value because of the composition of its oil seed. However, there are some constraints in your use for human and animal food because of the presence of toxic and allergenic proteins. This problem could be solved or reduced through genetic engineering. However, this crop is recalcitrant to tissue culture techniques, thus limiting the formation of transformed plants, and the protocols existing are not well established. The aim of this work was to test the applicability of the regeneration protocol which has been published for the Nordestina cultivar; to determine the regeneration way and to verify trough histochemical techniques, the transformed cells around the meristem. For this purpose, embryo axes were cultured on Murashig and Skoog (MS) medium supplemented with thiadiazuron (TDZ) (0,1; 0,5; 1,0; 2,0; 5,0 e 10,0 mg.L-1). Between the TDZ concentrations tested, 0,1 mg.L-1 presented the better results after 56 days of incubation with 7,42 shoots per explant. Gibberellic acid (GA3) (0,1 mg.L-1) and indole-3-butyric acid (1,0 mg.L-1) were used for elongation and rooting, respectively, of the shoots obtained, however, in the concentrations used, any effect was evidenced. Histological analysis revealed that the shoots were formed by pre existing or neo formed meristems indicating direct organogenesis. Transformed cells were viewed at least in the second cellular layer. Analysis for stable gus expression showed gus expression 19 days after bombardment. In the histological analysis transformed cells in process of division were observed. In conclusion the Nordestina cultivar formed multiple shoots on medium supplemented with TDZ and this protocol of regeneration was compatible with a protocol for biolistic-mediated transformation
2

Regeneration and Transformation of Impatiens walleriana Using Cotyledonary Node Culture

Baxter, Aaron Jacob 16 January 2006 (has links)
Impatiens walleriana, commonly grown as a herbaceous annual, is susceptible to Impatiens Necrotic Spot Virus (INSV). A lack of resistant cultivars leaves growers with the sole option of destroying infected plants before INSV spreads throughout their entire crop. Therefore, the introduction of INSV resistant cultivars would have the potential to save Impatiens growers a substantial amount of money. Virus resistance has been successfully conveyed in several crops by insertion of pathogen DNA into the host plant. One method of generating transgenic plants involves the use of Agrobacterium-mediated gene transfer. A commonly used technique involves transformation of explant tissue and subsequent regeneration in vitro under aseptic conditions. However, prior to our research there was no regeneration protocol suitable for Agrobacterium-mediated transformation of Impatiens walleriana available. Herein we report the development of a new method for regeneration of Impatiens walleriana using cotyledonary node culture. Using this technique, four regeneration media amended with 1, 3, 5, or 7µM of thidiazuron were evaluated for their ability to induce de novo shoot production in cotyledonary node explants, and evaluated for number of shoots produced per explant. Results showed a significantly greater frequency of regeneration and number of shoots per explant using media amended with 1µM of thidiazuron. This technique has shown to be repeatable and is not susceptible to ploidy instability. Unfortunately, damage to the cotyledonary node explants during Agrobacterium inoculation and transfection prevented regeneration of transformed shoots in several attempts. However, transient GFP expression after transfection of shoot pads derived from cotyledonary nodes with Agrobacterium strain LBA 4404 containing plasmid pHB2829 with nptII and S-GFP was obtained, indicating the possibility for this regeneration protocol to derive stably transformed Impatiens with INSV resistance. / Master of Science
3

Use of Plant Growth Regulators to Increase Branching of Clematis Spp.

Puglisi, Sadie Erica 18 October 2002 (has links)
Clematis spp. L. is a twining vine covered in showy blooms. Typical growth of hybrids is from the main leader, producing a thin, unbranched plant with one cyme. Apical dominance is released by cutting back the vine during production. Cutting back, or pinching, of a plant is labor intensive and compromises bloom for vegetative growth at time of sales. The purpose of this project was to eliminate manual pinching by treating young plants with chemical plant growth regulators (PGRs) that enhance branching without removal of the apical meristem. The first project evaluated the use of Atrimmec (dikegulac sodium), Fascination (BA+GA4+7), Florel (ethephon), and Dropp 50 (thidiazuron) on Clematis cultivars Ernest Markham, and Hagley Hybrid, and Clematis viticella 'Polish Spirit.' Plants treated with 800 mg·L-1 Atrimmec, or 800 or 1200 mg·L-1 Fascination experienced an increase in branch numbers. The second experiment manipulated the ratio of the components of Fascination, 6-BA and GA4+7, to reduce phytotoxicity experienced in the first experiment. The optimal ratio to enhance branching was 1:1, which is the stock solution for Fascination. All ratios produced phytotoxic symptoms. A third experiment tested lower rates of thidiazuron and added CPPU (forchlorfenuron) to the list of PGRs to test. The last experiment took the most effective PGR treatments, Atrimmec at 800 mg·L-1, and Fascination at 800 or 1200 mg·L-1, and compared them to the current production practices of pinching. Large flowering cultivars of clematis were used, including 'Comotesse de Bouchard,' 'Ernest Markham,' and 'Hagley Hybrid.' Atrimmec increased branch numbers and suppressed leader lengths without a mechanical pinch. Results from Fascination varied by cultivar. / Master of Science
4

Fitorreguladores em pereiras europeias: fruit set, produtividade e qualidade de frutos / Growth regulators in European pear: fruit set, yield and fruit quality

Luz, Alberto Ramos 16 February 2012 (has links)
Made available in DSpace on 2016-12-08T16:44:41Z (GMT). No. of bitstreams: 1 PGPV12MA094.pdf: 1832158 bytes, checksum: 12087c58319ad6a4e92485eaff5983f5 (MD5) Previous issue date: 2012-02-16 / The pear is the third most temperature fruit consumed in Brazil, representing the largest percentage of total frsh fruit imports by country (50.7% of the amount). Brazilian production is not significant, with low fruit set as one of the main problems of low productivity of pear trees in southern Brazil. In this context, this study aimed to evaluate the main growth regulators (Promalin®, Viviful®, Retain®, and TDZ) for the cultivation of the pear growing in different locations in southern brazil and its effect on fruit ser and yield of pear Packam s Triumph and William s . The experiments were conducted in the regions of São Joaquim, SC, Rio Rufino, SC and São Francisco de Paula, RS, during the growing seasons 2009/2010 and 2010/2011, with cultivars Packam s Triumph and William s. We evaluate the fruit set, number of fruits per plant, yield per plant, estimated yield, fruit diameter, deformation, flesh firmness, number of viable and unviable seeds, soluble solids, pH and titratable acidity. The results indicate that cv. Packam s Triumph is more responsive to the action of growth regulators than cv. William s. Since, Promalin® (1 ml L-1) applied at the full bloom + Retain® (2 g L-1) applied 15 days after the full bloom increases the productivity of pear Packham s Trimph, and pear William s, the increase only happened in the counties of São Joaquim and São Francisco de Paula. The use growth regulators did not increase the productivity of the pear tree William s in the experimental area of São Joaquim. The application of Viviful® increased the productivity of pear William s in the experimental area of San Francisco de Paula. The use growth regulators Retain®, Viviful®, TDZ and Promaline® + Retain® increase the fruit set of pear Packham s Triumph, emphasizing the application of Promaline® (1 ml L-1) applied at full bloom + Retain® (2 f L-1) applied 15 days after full bloom, which increased fruit set and productivity / A pera é a terceira fruta de clima temperado mais consumida no Brasil, representando a maior porcentagem no total dos frutos in natura importados pelo país (50,7% da quantidade). A produção brasileira é pouco expressiva, apresentando baixo pegamento de frutos como um dos principais problemas da baixa produtividade das pereiras no sul do Brasil. Neste contexto, o presente trabalho teve como objetivo, avaliar os principais fitorreguladores (Promalin®, Viviful®, Retain® e Thidiazuron) para a cultura da pereira em diferentes locais de cultivo no sul do Brasil e o seu efeito na fruit set e produtividade das pereiras Packham‟s Triumph e William‟s . Os experimentos foram conduzidos nas regiões de São Joaquim, SC, Rio Rufino, SC e São Francisco de Paula, RS durante as safras 2009/2010 e 2010/2011, com as cultivares Packham‟s Triumph e William‟s. Foram avaliados a fruit set, nº de frutos por planta, produtividade por planta, produtividade estimada, diâmetro de frutos, deformação, firmeza de polpa, nº de sementes viáveis e inviáveis, sólidos solúveis, pH e acidez titulável. Os resultados obtidos indicam que a cv. Packham‟s Triumph responde mais à ação dos fitorreguladores do que a cv. William‟s. Sendo que, Promalin® (1 ml L-1) aplicado no estádio de plena floração + Retain® (2 g L-1) aplicado 15 dias após a plena floração aumentam a produtividade da pereira Packham‟s Triumph, e na pereira William‟s, o aumento só aconteceu nos municípios de São Joaquim e São Francisco de Paula. O uso de fitorreguladores não aumentou a produtividade da pereira William‟s na área experimental de São Joaquim. A aplicação de Viviful® aumentou a produtividade das pereiras William‟s na área experimental de São Francisco de Paula. O uso dos fitorreguladores Retain®, Viviful®, TDZ e Promalin® + Retain® aumentam a fruit set da pereira Packham‟s Triumph, destacando-se a aplicação de Promalin® (1 ml L-1) aplicado no estádio de plena floração + Retain® (2 g L-1) aplicados 15 dias após a plena floração, o qual aumentou a fruit set e a produtividade
5

The Effects Of Thidiazuron On Callus Development And Organogenesis From Mature Embryos Of Selected Turkish Bread And Durum Wheat Varieties

Yaqubov, Nihad 01 July 2004 (has links) (PDF)
The effects of cytokinin-like Thidiazuron growth regulator on the regeneration responses of callus cultures of Turkish bread Triticum aestivum L. cv. (BaSak 95, Gerek 79, and Bezostaja 1) and durum Triticum durum Desf. cv. (Kunduru, &Ccedil / akmak 79, and Kirmizi 5132) wheat varieties have been investigated in this study. High callus induction frequencies are found to be independent of bread and durum wheat varieties ( &rsaquo / 96%) whereas the callus weight is found to be variety-dependent. For bread wheat, BaSak 95 and for the durum wheat Kunduru is found to be the best performers. TDZ treatments are found to be negatively affecting the regeneration capacity of all the tested bread wheat varieties whereas for the durum wheat variety of Kunduru positive effect is observed. Since the culture efficiency is a derivation from the regeneration capacity, this parameter yielded very similar results as in the case of regeneration capacity for both bread and durum wheat varieties. In bread wheat varieties, the TDZ treatments increased the number of regenerated plants more than 2-fold when compared with the control and likewise very similar results were obtained from durum wheat varieties. Unfortunately, following their transfer to soil, plants that were treated with various concentrations of TDZ displayed reduced vigor probably due to underdeveloped roots. In addition, majority of these plants did not sufficiently develop above the ground parts when compared with the control plants. The simplicity and rapid development of shoots using mature embryos could potentially be used for regenerating superior plants following gene transfer studies in the future.
6

Somatic embryogenesis for micropropagation of coconut (Cocos nucifera L.)

Irina Antonova Unknown Date (has links)
Coconut (Cocos nucifera L.) is native to the regions between 20oN and 20oS of the Equator, where it plays a significant socioeconomic role in the local communities. There it is referred to as ’The Tree of Life’, a eulogistic epithet describing its versatile use - more than 100 edible and non-edible products can be produced from it. Therefore the coconut palm is grown in about 90 tropical countries on more than 10 millions ha of land (Hamon et al., 1999). Although coconut has a high local socioeconomic reputation, its production is experiencing many problems and consequently the area planted with this crop is declining. The conventional breeding approach using seed to replant land is very expensive due to the low production of seed for planting, and even when elite germplasm is available it takes decades to multiply up enough planting material for new areas (Adkins et al., 1999). Hence over the past 40 years research has been directed towards developing a new technique for the micropropagation of coconut using somatic embryogenic approach. Throughout this time however one conclusion is repeatedly made – coconut is very recalcitrant to somatic embryogenesis. And although the many obstacles to this are slowly being reduced, in order to successfully micropropagate coconut on a large scale bottlenecks in the protocol still exist, and those include inconsistency of the embryogenic response by explanted tissues, poor somatic embryo maturation and germination, low regeneration rate of the new plantlets and long time required to produce plants (1.5 years) (Samosir et al., 1998). These bottlenecks and other problems were researched in the present study with the aim of trying to speed up the efficiency of coconut somatic embryogenesis process. Hence this thesis had the objectives to identify a starting protocol for coconut somatic embryogenesis; to select an appropriate for aim that explant; to optimize the production of embryogenic callus; to increase the rate of initiating coconut somatic embryos; to improve the maturation of somatic embryos and their germination efficiency; and to optimize the regeneration rate of the new plantlets. In order to identify a starting protocol, preliminary work was conducted, where existing protocols for coconut somatic embryogenesis were compared in their efficiency to induce somatic embryos. The protocol that stood out as the best in producing most embryogenic callus and subsequently embryos, as well as having the least dead (in culture) explants, was that of Nikmatullah (2001). Therefore the latter was chosen to be used as a starting protocol for this study. New sources of explants were investigated during the current work as well, using tissues from different parts of in vitro derived 8 months old coconut plantlets. Those however have shown to be unsuitable for somatic embryogenesis, since only non-embryogenic callus was developed by some of the inoculated tissues. The immature inflorescence explants were superior in producing embryogenic callus and somatic embryos; therefore they were selected as the preferred explant source to use in the next steps of the current study. Optimizing the production of embryogenic callus was the first issue to address during the core work of this project. As a result of that the culture conditions were considerably improved by using vessels with larger headspace-medium ratio (3:1), as well as by selecting younger immature inflorescences and transversely segmenting the top half of the inflorescence spikes into smaller size (1 mm) sections. Further improvement was possible by studying the make up of the callus growth media. Amongst the administered for that purpose substances the applied together polyamines spermine (0.10 µM) and putrescine (7.5 mM) have proven to play a notably positive role in the induction of callus from coconut immature inflorescence explants. Thidiazuron (TDZ, 10 µM) too has shown a potential to improve the efficiency of the initial stage of coconut somatic embryogenesis, but only when applied in conjunction with other cytokinins (eg. BAP and 2iP). Smoke-saturated-water (SSW, 10 %) could only slightly diminish the amount of necrotising cultured explants, and high 2,4-D concentrations could not support the induction of callus from immature coconut inflorescences. Collectively taken, as a result of this current study the production of callus was improved by 300 %. The rate of coconut somatic embryos formation was as well significantly increased (over 300 %), by the simultaneous application of suspension culture step, spermine (0.01 µM), SSW (10 %) and high auxin concentration (500 µM). Nevertheless the presence of TDZ and other cytokinins in the medium, as well as the absence of activated charcoal, were found to be unable to positively influence the somatic embryogenesis process. Despite the considerable improvements made in the efficiency of inducing callus and initiating embryos, the poor maturation and germination (eg. 5 %, Verdeil et. al., 1999) of somatic embryos still remained a bottleneck to the whole somatic embryogenesis procedure. Therefore further work was conducted in that direction and discovered that embryo maturation and germination rate can be elevated to 55 % by administering ancymidol (30 µM) to the somatic embryo maturation medium. This plant retardant has exhibited here three potential modes of action towards the cultured coconut somatic embryos: a) as a promoter of somatic embryo maturation and germination; b) as a preventor of pre-germination death of the somatic embryos; and c) as a preserver of non-germinating somatic embryos, that still can possess the potential to germinate in the future. The work during the next step of the process – regeneration of the new plantlets – has shown that the omission of plant growth regulators from the media was crucial for the development of germinated embryos into new plantlets, where otherwise no plant regeneration occurred at all. The achieved here plantlet regeneration rate in the PGR-free medim was 56 %, which is higher than the previously reported 20 % regeneration rate (Verdeil et al., 1994) for coconut plantlets produced from immature inflorescences explants. As a result of this current work a new method was developed for somatic embryogenesis of coconut from immature inflorescences explants (Fig. 9.2). The overall efficiency of this protocol is over three times higher than that of the starting protocol (Nikmatullah, 2001) selected during the preliminary work. Furthermore, when using this new method the entire duration for regenerating clonal coconut plantlets (up to the stage of first root and shoot emerging) takes up to 8 months, which is the shortest reported time for producing coconut plantlets via somatic embryogenesis (eg. 36 months from inflorescences explants (Verdeil et. al., 1999) and 18 months from sliced zygotic explants (Samosir, 1999, Fig. 9.2), presenting an additional valuable advantage of this newly developed method, from the perspective of the potential to micropropagate coconut on a commercial scale.
7

Somatic embryogenesis for micropropagation of coconut (Cocos nucifera L.)

Irina Antonova Unknown Date (has links)
Coconut (Cocos nucifera L.) is native to the regions between 20oN and 20oS of the Equator, where it plays a significant socioeconomic role in the local communities. There it is referred to as ’The Tree of Life’, a eulogistic epithet describing its versatile use - more than 100 edible and non-edible products can be produced from it. Therefore the coconut palm is grown in about 90 tropical countries on more than 10 millions ha of land (Hamon et al., 1999). Although coconut has a high local socioeconomic reputation, its production is experiencing many problems and consequently the area planted with this crop is declining. The conventional breeding approach using seed to replant land is very expensive due to the low production of seed for planting, and even when elite germplasm is available it takes decades to multiply up enough planting material for new areas (Adkins et al., 1999). Hence over the past 40 years research has been directed towards developing a new technique for the micropropagation of coconut using somatic embryogenic approach. Throughout this time however one conclusion is repeatedly made – coconut is very recalcitrant to somatic embryogenesis. And although the many obstacles to this are slowly being reduced, in order to successfully micropropagate coconut on a large scale bottlenecks in the protocol still exist, and those include inconsistency of the embryogenic response by explanted tissues, poor somatic embryo maturation and germination, low regeneration rate of the new plantlets and long time required to produce plants (1.5 years) (Samosir et al., 1998). These bottlenecks and other problems were researched in the present study with the aim of trying to speed up the efficiency of coconut somatic embryogenesis process. Hence this thesis had the objectives to identify a starting protocol for coconut somatic embryogenesis; to select an appropriate for aim that explant; to optimize the production of embryogenic callus; to increase the rate of initiating coconut somatic embryos; to improve the maturation of somatic embryos and their germination efficiency; and to optimize the regeneration rate of the new plantlets. In order to identify a starting protocol, preliminary work was conducted, where existing protocols for coconut somatic embryogenesis were compared in their efficiency to induce somatic embryos. The protocol that stood out as the best in producing most embryogenic callus and subsequently embryos, as well as having the least dead (in culture) explants, was that of Nikmatullah (2001). Therefore the latter was chosen to be used as a starting protocol for this study. New sources of explants were investigated during the current work as well, using tissues from different parts of in vitro derived 8 months old coconut plantlets. Those however have shown to be unsuitable for somatic embryogenesis, since only non-embryogenic callus was developed by some of the inoculated tissues. The immature inflorescence explants were superior in producing embryogenic callus and somatic embryos; therefore they were selected as the preferred explant source to use in the next steps of the current study. Optimizing the production of embryogenic callus was the first issue to address during the core work of this project. As a result of that the culture conditions were considerably improved by using vessels with larger headspace-medium ratio (3:1), as well as by selecting younger immature inflorescences and transversely segmenting the top half of the inflorescence spikes into smaller size (1 mm) sections. Further improvement was possible by studying the make up of the callus growth media. Amongst the administered for that purpose substances the applied together polyamines spermine (0.10 µM) and putrescine (7.5 mM) have proven to play a notably positive role in the induction of callus from coconut immature inflorescence explants. Thidiazuron (TDZ, 10 µM) too has shown a potential to improve the efficiency of the initial stage of coconut somatic embryogenesis, but only when applied in conjunction with other cytokinins (eg. BAP and 2iP). Smoke-saturated-water (SSW, 10 %) could only slightly diminish the amount of necrotising cultured explants, and high 2,4-D concentrations could not support the induction of callus from immature coconut inflorescences. Collectively taken, as a result of this current study the production of callus was improved by 300 %. The rate of coconut somatic embryos formation was as well significantly increased (over 300 %), by the simultaneous application of suspension culture step, spermine (0.01 µM), SSW (10 %) and high auxin concentration (500 µM). Nevertheless the presence of TDZ and other cytokinins in the medium, as well as the absence of activated charcoal, were found to be unable to positively influence the somatic embryogenesis process. Despite the considerable improvements made in the efficiency of inducing callus and initiating embryos, the poor maturation and germination (eg. 5 %, Verdeil et. al., 1999) of somatic embryos still remained a bottleneck to the whole somatic embryogenesis procedure. Therefore further work was conducted in that direction and discovered that embryo maturation and germination rate can be elevated to 55 % by administering ancymidol (30 µM) to the somatic embryo maturation medium. This plant retardant has exhibited here three potential modes of action towards the cultured coconut somatic embryos: a) as a promoter of somatic embryo maturation and germination; b) as a preventor of pre-germination death of the somatic embryos; and c) as a preserver of non-germinating somatic embryos, that still can possess the potential to germinate in the future. The work during the next step of the process – regeneration of the new plantlets – has shown that the omission of plant growth regulators from the media was crucial for the development of germinated embryos into new plantlets, where otherwise no plant regeneration occurred at all. The achieved here plantlet regeneration rate in the PGR-free medim was 56 %, which is higher than the previously reported 20 % regeneration rate (Verdeil et al., 1994) for coconut plantlets produced from immature inflorescences explants. As a result of this current work a new method was developed for somatic embryogenesis of coconut from immature inflorescences explants (Fig. 9.2). The overall efficiency of this protocol is over three times higher than that of the starting protocol (Nikmatullah, 2001) selected during the preliminary work. Furthermore, when using this new method the entire duration for regenerating clonal coconut plantlets (up to the stage of first root and shoot emerging) takes up to 8 months, which is the shortest reported time for producing coconut plantlets via somatic embryogenesis (eg. 36 months from inflorescences explants (Verdeil et. al., 1999) and 18 months from sliced zygotic explants (Samosir, 1999, Fig. 9.2), presenting an additional valuable advantage of this newly developed method, from the perspective of the potential to micropropagate coconut on a commercial scale.
8

Uso de fitorreguladores para controle do desenvolvimento vegetativo e aumento da frutificação em macieira e pereira. / Use of growth regulators to control vegetative growth and frutification increase in apple and pear trees

Hawerroth, Fernando José 23 November 2010 (has links)
Made available in DSpace on 2014-08-20T14:22:08Z (GMT). No. of bitstreams: 1 Tese_Fernando_Jose_Hawerroth.pdf: 6659971 bytes, checksum: e37f7fea29ee58245d356204894a8ce6 (MD5) Previous issue date: 2010-11-23 / The proper balance between vegetative growth and frutification in pome fruit species such as apple and pear, it is essential to increase production efficiency and improving fruit quality. In this sense, control of vegetative growth and frutification increase are needed in the management of these species, which may be obtained by use of growth regulators. The objective of this study was to evaluate the control of vegetative growth and frutification increase of apple and pear orchards in the Southern Brazil climatic conditions in response to the use of growth regulators. For this, three experiments were carried out in this research. In the first experiment, different concentrations of prohexadione calcium were evaluated in 'Imperial Gala' and 'Fuji Suprema' apple trees, grafted on Marubakaido rootstock with M9 interstock, in an orchard located in Fraiburgo/SC. The treatments (0, 165, 330, 495, 660, and 990 g ha-1 prohexadione calcium) were applied during the vegetative growth in 2008/2009 and 2009/2010 growing seasons. The concentrations corresponding to each treatment were applied split into three parts. The first application was done when the shoots of the control treatment showed growth of 10 cm. The second and third applications were made at 30 and 60 days after the first application, respectively. The prohexadione calcium was effective in controlling vegetative growth of apple trees 'Imperial Gala' and 'Fuji Suprema', reducing the total weight and average weight of pruned shoots, as well as the average shoot length, in the Southern Brazil climatic conditions. The use of prohexadione calcium at concentrations ranging from 165 to 330 g ha-1 increased the fruit production of 'Imperial Gala' apples, but high concentrations of this growth regulator tends to reduce the fruit production, especially in 'Fuji Suprema' apples. The reduction of vegetative growth by the use of prohexadione calcium contributed to increase calcium content in fruits of 'Fuji Suprema'. The second experiment was carried out in Pelotas/RS, using 'Hosui' pears grafted on Pyrus calleryana rootstock. Different 8 concentrations of prohexadione calcium were evaluated (0, 275, 550, and 825 g ha- 1), being half the concentration corresponding to each treatment applied when the shoots had between 5 to 10 cm in length, and the remainder applied 30 days after the first application. The use of prohexadione calcium was effective in controlling the vegetative growth of 'Hosui' pears, decreasing the need for winter pruning by reducing the total weight and the number of shoots pruned. The control of vegetative growth by use of prohexadione calcium determined increase the productive capacity of 'Hosui pears, especially at concentrations ranging from 450 to 750 g ha-1. The aim of the third experiment was to evaluate the effectiveness of thidiazuron, gibberellic acid, prohexadione calcium and combination of these substances on frutification increase of 'Shinseiki' asian pears. The following treatments were applied at full bloom: 1. control (no application); 2. thidiazuron (TDZ) 20 mg L-1; 3. gibberellic acid (GA) 20 mg L-1; 4. prohexadione calcium (PCa) 600 mg L-1; 5. PCa 600 mg L-1 + TDZ 20 mg L-1; 6. PCa 600 mg L-1 + AG 20 mg L-1; e 7. AG 20 mg L-1 + TDZ 20 mg L-1. The application thidiazuron at 20 mg L-1, gibberellic acid at 20 mg L-1 and the combination of these substances during the full bloom increased significantly the frutification and the fruit production of 'Shinseiki' pears. The prohexadione calcium, when sprayed at flowering alone or in combination to thidiazuron and gibberellic acid, was not effective to increase the fruit set and fruit production. The use of growth regulators on flowering decreased the number of seeds per fruit. / O adequado balanço entre o desenvolvimento vegetativo e a frutificação em espécies pomáceas, como a macieira e a pereira, é fundamental ao aumento da eficiência produtiva e a melhoria da qualidade dos frutos. Neste sentido, o controle do desenvolvimento vegetativo e o aumento da frutificação são necessários no manejo de tais espécies, podendo ser obtidos pelo uso de fitorreguladores. Objetivou-se com este estudo avaliar o controle do desenvolvimento vegetativo e o aumento da frutificação de macieiras e de pereiras nas condições climáticas do Sul do Brasil em resposta ao uso de fitorreguladores. Para tanto, foram realizados três experimentos. No primeiro experimento, foram avaliadas diferentes concentrações de proexadione cálcio em macieiras Imperial Gala e Fuji Suprema , enxertadas no porta-enxerto Marubakaido com interenxerto de M9, em pomar localizado em Fraiburgo/SC. Os tratamentos (0; 165; 330; 495; 660; e 990 g ha-1 de proexadione cálcio) foram aplicados durante o período de desenvolvimento vegetativo nos ciclos 2008/2009 e 2009/2010. As concentrações respectivas a cada tratamento foram aplicadas parceladamente em três momentos. A primeira aplicação foi realizada quando as brotações do tratamento testemunha apresentavam crescimento de 10 cm. A segunda e a terceira aplicação foram realizadas aos 30 e 60 dias após a primeira aplicação, respectivamente. O proexadione cálcio foi eficiente no controle do desenvolvimento vegetativo de macieiras Imperial Gala e Fuji Suprema , reduzindo a massa total e a massa média de ramos, assim como o comprimento médio dos ramos, nas condições climáticas do Sul do Brasil. O uso de proexadione cálcio em concentrações variando de 165 a 330 g ha-1 aumentou a produção de maçãs Imperial Gala , porém altas concentrações deste fitorregulador tendem a reduzir a produção de frutos por planta, sobretudo em macieiras Fuji Suprema . A redução do desenvolvimento vegetativo pelo uso do proexadione cálcio contribuiu 6 para o aumento dos teores de cálcio em maçãs Fuji Suprema . O segundo experimento foi realizado no município de Pelotas/RS, utilizando pereiras Hosui enxertadas no porta-enxerto Pyrus calleryana. Foram avaliadas diferentes concentrações de proexadione cálcio (0; 275; 550; e 825 g ha-1), sendo metade da concentração respectiva a cada tratamento aplicada quando as brotações apresentavam entre 5 a 10 cm de comprimento, e o restante aplicado 30 dias após a primeira aplicação. O uso de proexadione cálcio foi efetivo no controle do desenvolvimento vegetativo de pereiras Hosui , minimizando a necessidade de poda hibernal pela redução da massa total e do número de ramos podados. O controle do desenvolvimento vegetativo pelo uso de proexadione cálcio determinou aumento da capacidade produtiva de pereiras Hosui , sobretudo em concentrações de 450 a 750 g ha-1. O objetivo do terceiro experimento foi avaliar a efetividade do thidiazuron, ácido giberélico, proexadione cálcio e a combinação destas substâncias no aumento da frutificação de pereiras asiáticas Shinseiki . Os seguintes tratamentos foram aplicados na plena floração: 1. testemunha (sem aplicação); 2. thidiazuron (TDZ) 20 mg L-1; 3. ácido giberélico (AG) 20 mg L-1; 4. proexadione cálcio (PCa) 600 mg L-1; 5. PCa 600 mg L-1 + TDZ 20 mg L-1; 6. PCa 600 mg L-1 + AG 20 mg L-1; e 7. AG 20 mg L-1 + TDZ 20 mg L-1. A aplicação de thidiazuron 20 mg L-1, ácido giberélico 20 mg L-1 e a combinação destas substâncias durante a plena floração aumentaram significativamente a frutificação e a produção de pereiras Shinseiki . O proexadione cálcio, quando aplicado na floração isoladamente ou em combinação ao thidiazuron e ao ácido giberélico, não se mostrou efetivo no aumento da frutificação e na produção de frutos. A utilização dos fitorreguladores na floração diminuiu o número médio de sementes por fruto.
9

Shipping and nitrogen toning effects on postharvest shelf life of vegetative annuals

Beach, Shannon Elizabeth 30 October 2006 (has links)
Vegetative annuals are currently popular in the ornamental horticulture industry. Many crops are newly domesticated species and little is known about how they perform during shipping or in the retail environment. Nine species and 21 cultivars were grown and underwent simulated shipping after harvest or nitrogen toning two weeks before harvest. Shipping was not found to affect the number of flowers on all but two cultivars post ship. Nitrogen toning affected vegetative growth of most Bracteantha bracteata (bracteantha) cultivars at harvest. All species had an effect due to toning postharvest. Bractenatha and Diascia ×hybrida (diascia) were chosen for further study due to their performance during these experiments. The effect of thidiazuron (TDZ) as a foliar spray and nitrogen toning on leaf yellowing and plant growth of bracteantha were evaluated. The two treatments were then combined to see how the two treatments worked together. It was found TDZ decreased leaf yellowing but its effects can be negated if the plants were not toned. Nitrogen toning reduced vegetative growth of the bracteantha without affecting the number of flowers on the plants. Diascia was found to have flower abscission in response to shipping. Further trials were conducted using 1- methylcyclopropene (1-MCP) an ethylene inhibitor. The effects of shipping duration and temperature were investigated. 1-MCP was found to hold flowers on treated plants longer postharvest than those not treated. Plants shipped for one day had no differences from the control but shipping for two days had a negative effect on plant quality. Postharvest shelf life was decreased when diascia was shipped at 24 °C when compared to cooler shipping temperatures. These results indicate shipping for no longer than one day and at less than 24 °C is recommended for diascia.

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