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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.
31

Genetic and environmental factors affecting rooting in Eucalyptus grandis X Eucalyptus longirostrata hybrid cuttings.

Naidoo, Nuveshen. January 2011 (has links)
In clonal deployment programmes of plantation species, there is frequently the need to deploy Eucalyptus species and interspecific hybrids as rooted cuttings. However, the rooting ability of a particular species or hybrid is a major, and usually limiting, factor affecting the economics of commercial deployment. There is also significant between-species and between-family variation for this trait. Recently, Eucalyptus longirostrata was crossed with E. grandis in an effort to combine its desirable wood properties, drought tolerance and disease resistance with the latter's vigorous growth. Should progeny with these suitable characteristics be identified, there is the possibility of extending plantations to more marginal areas and increasing the quality and volume from existing plantations. An investigation was undertaken to study the rooting ability of E. grandis x E. longirostrata hybrid cuttings. The plant material was sourced from five families in seedling derived hedges at two nurseries, as well as five families coppiced from an unreplicated progeny trial planted in the midlands of KwaZulu-Natal. Their rooting ability was assessed by determining the percentage of cuttings that developed roots using two different rooting methods. The variation between and within families and clones is presented. The study shows that root strike is under moderate genetic control, with an estimate of broad-sense rooting heritability of 0.197 (S.E. = 0.070). The two nurseries used in this study used different rooting technologies, with cuttings rooted either in media (traditional method) or in air (aeroponically). The aeroponics technology was highly significantly (p<0.0001) superior, in terms of rooting success. Rooting was also highly significantly affected (p<0.0001) by the temperature at the time of cutting. Rooting success of cuttings from seedling-derived parental hedges was similar to cuttings from coppiced stumps. The consequences of the low repeatability of measurements of rooting ability, 0.187 (S.E. 0.067) by clone and 0.340 (S.E. 0.072) by ramet, which was influenced by the response to age of material and nursery conditions, is discussed. This study demonstrated that large improvements in rooting success can be made by the optimization of rooting protocols and selecting for superior genotypes, as long as the performances of genotypes are accurately assessed. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
32

Análises bioquímicas e hsitológicas na micropropagação de abacaxizeiro 'Gomo de Mel' submetido a reguladores vegetais /

Fráguas, Chrystiane Borges, 1976- January 2006 (has links)
Orientador: Giuseppina Pace Pereira Lima / Banca: João Domingos Rodrigues / Banca: Moacir Pasqual / Banca: Antonio Natal Gonçalves / Banca: Alessandra Marcondes Feijó Viu / Resumo: Este trabalho teve como objetivo avaliar os efeitos da aplicacao exogena de poliaminas e TIBA (antiauxina) na micropropagacao e anatomia foliar de plantulas de abacaxizeiro eIAC Gomo-de-melf e analisar os teores de poliaminas endogenas, atividade de peroxidase, proteina, IAA-oxidase e a provavel relacao com as diferentes fases da micropropagacao. Inicialmente, retiraram-se as gemas da coroa de frutos sadios e a assepsia foi realizada com hipoclorito de sodio comercial (2 a 2,5% de cloro ativo) a 30% por 20 minutos e lavadas por 3 vezes em agua destilada e autoclavada. Em seguida, inocularam-se as gemas em meio MS solido contendo diferentes combinacoes de BAP (0; 0,5; 1,0 e 1,5 mg L-1) e NAA (0; 0,5 e 1,0 mg L-1). Apos 60 dias, foram selecionados os melhores tratamentos para proliferacao das brotacoes, que foram individualizadas e transferidas para estes meios por mais trinta dias, em meio MS liquido. Plantas oriundas do experimento anterior tiveram as folhas cortadas e apenas segmentos de 1 cm foram inoculados em meio MS liquido contendo os diferentes tratamentos: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPD, T4-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPM, T5-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM PUT, T6-MS + 10 mM SPD, T7-MS + 10 mM SPM e T8-MS + 10 mM PUT. Na ultima fase, segmentos foram inoculados em meio MS liquido contendo os tratamentos: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 0,5 ƒÊM TIBA, T4-MS + 1,0 ƒÊM TIBA, T5-MS + 2,0 ƒÊM TIBA, T6-MS + 4,0 ƒÊM TIBA, T7-MS + 8,0 ƒÊM TIBA e T8-MS + 16,0 ƒÊM TIBA. Apos, as plantas foram aclimatizadas em substrato Plantmax e houve 100% de sobrevivencia, independente do tratamento. Foram realizados cortes histologicos foliares para estudar a influencia das poliaminas e TIBA na anatomia foliar...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The effects of exogenous polyamines and TIBA (antiauxin) application in the micropropagation, leaf anatomy of pineapple plants ‘IAC Gomo-de-mel’ and the contents of endogenous polyamines, peroxidase activity, protein, IAA-oxidase and probable relationship with the different micropropagation phases were studied. Initially, the axillary bud explants were excised from the crown of healthy fruits and the asepsis was accomplished with sodium hypochloride (2 to 2,5% of active chlorine) 30% for 20 minutes and washed 3 times in distilled and autoclaveted water. After, the axillary buds were inoculated in MS solid medium containing the different BAP (0; 0,5; 1,0 and 1,5 mg L-1) and NAA (0; 0,5 and 1,0 mg L-1) combinations. After 60 days, the best treatments were selected for shoot proliferation that were individualized and transferred to these media for more 30 days, in MS liquid medium. Plants from the previous experiment had the leaves cut and just 1 cm segments were inoculated in MS liquid medium containing the different treatments: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPD, T4- MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM SPM, T5-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA + 10 mM PUT, T6-MS + 10 mM SPD, T7-MS + 10 mM SPM and T8-MS + 10 mM PUT. In the last phase, segments were inoculated in MS liquid medium containing the treatments: T1-MS, T2-MS + 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, T3-MS + 0,5 mM TIBA, T4-MS + 1,0 mM TIBA, T5-MS + 2,0 mM TIBA, T6-MS + 4,0 mM TIBA, T7-MS + 8,0 mM TIBA and T8-MS + 16,0 mM TIBA. After, the plants were acclimatizated in Plantmax substrate and there were 100% survival, independent of the treatment. Leaf cuts were made to study polyamines and TIBA influence in the leaf anatomy. The highest shoot number wasobserved with 1,0 mg L-1 BAP + 0,5 mg L-1 NAA, however with hyperhydricity...(Complete abstract click electronic access below) / Doutor
33

Propagação de jamboleiro [Syzygium cumini (L.) Skeels] / Propagation of Syzygium cumini (L.) Skeels

Silva, Marciéli 23 March 2017 (has links)
Syzygium cumini (L.) Skeels é espécie exótica nativa da Ásia, porém seu cultivo está espalhado em vários países, nos quais inclui-se o Brasil. Apesar de existir poucos plantios comerciais dessa fruteira, ela apresenta inúmeras possibilidades de uso, desde o mercado de frutas frescas até o processamento como compotas, licores, vinagre, geleias, tortas e doces. O objetivo deste trabalho foi testar técnicas de propagação visando obter protocolo apropriado para esta espécie. Os experimentos foram feitos no Laboratório de Fisiologia Vegetal e Unidade de Ensino e Pesquisa Viveiro de Produção de Mudas, da Universidade Tecnológica Federal do Paraná - Câmpus Dois Vizinhos. O armazenamento de sementes de jamboleiro foi realizado nos tempos de 0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330 e 360 dias. O armazenamento seguido de hidrocondicionamento foi em temperatura de 25 °C por 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144 e 156 horas. Em ambos, percorrido cada período de tempo, as sementes foram postas para germinar e aos 60 dias avaliaram-se a porcentagem de germinação, índice de velocidade de germinação e tempo médio de germinação. Na mini-estaquia testou-se concentrações de ácido indol-butírico (AIB) (0, 2000, 3000 e 4000 mg.L-1) e tipo de estaca (Apical, mediana e basal). No experimento de estaquia testou-se concentrações de AIB (0, 5000 e 10000 mg.L-1) e concentrações de Benzilaminopurina (BAP) (0, 250 e 500 mg.L-1). No segundo experimento de estaquia testou-se técnicas de condicionamento (Ttestemunha, anelamento e alumínio), tempo de condicionamento (40, 60, 80 e 100 dias) e concentrações de AIB (0, 2000 e 4000 mg.L-1). Na alporquia foram empregados tipos de revestimento (papel transparente, papel alumino e plástico preto), concentrações de AIB (0, 2000 e 4000 mg.L-1), presença ou não de algodão e estações do ano. Tanto para mini-estaca, estaquias e alporquia analisaram-se a porcentagem de enraizamento, número de raiz, comprimento das três maiores raízes e presença de calo para alporquia e estaquia. Para o jamboleiro recomendou-se o armazenamento seguido de hidrocondicionamento por até 156 horas, a mini-estaquia mediana e basal sem a aplicação de AIB. E a alporquia foi o método que mais se destacou com maiores valores de enraizamento. / Syzygium cumini (L.) Skeels is an exotic species native to Asia, but its is cultivated a lot of countries, including Brazil. Although there are few commercial plantations of this fruit tree, it has many possibilities of commercialization, market of fresh fruits to processing such as jams, liqueurs, vinegar, jellies, pies and sweets. The objective of the work was to test propagation techniques in order to obtain an appropriate protocol for this species. The experiments were carried out in the Laboratory of Plant Physiology and Unit of Teaching and Research Nursery, at Federal Technological University of Paraná - Câmpus Dois Vizinhos. The storage of S. cumini seeds was during 0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330, 360 days. The storage followed by hydrocondicionamento in temperature of 25 °C during 0, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144 and 156 hours. The germination percentage, germination speed index and average germination time after 60 days were evaluated, according each time. In the mini-cuttings, indole-butyric acid (IBA) concentrations (0, 2000, 3000, 4000 mg.L-1) and type of cuttings (apical, middle and basal) were tested. In the cutting experiment, IBA concentrations (0, 5000, 10000 mg.L-1) and Benzylaminopurine (BAP) concentrations (0, 250 and 500 mgL-1) were evaluated. In the second cutting experiment, conditioning techniques (control, ringing and etiolation), conditioning time (40, 60, 80 and 100 days) and IBA concentrations (0, 2000, 4000 mg.L-1) were tested. In the air layering we used types of coating (withoutcolor plastic, aluminum paper and black plastic), IBA concentrations (0, 2000 and 4000 mg.L-1), presence or not of cotton and seasons of the year. In order to evaluate the percentage of rooting, root number, length of the three largest roots, and presence of callus by cuttingFor the S. cumini it was recommended the storage followed by hydrocondicionamento for up to 156 hours, the use of middle and basal minicuttings without the IBA application. The air layering was the technique propagation that it was possible higher rooting values.
34

Characterisation of rhizobacterial communities of Eucalyptus species and hybrids

Patrick, Melanie January 2013 (has links)
Thesis (M. Tech. (Agriculture)) -- Central University of Technology, Free State, 2013 / ntroduction: Good quality Eucalyptus is of importance to South Africa’s pulp and paper industry. Limited land is available for forestry, therefore Eucalyptus with genotypes for good pulp and paper qualities, particularly hybrids, are bred and cloned via cuttings. Although these Eucalyptus clones keep the favourable genotypes in the population, many have difficulty with rooting. Research has shown that rhizobacteria can improve rooting. Thus, one strategy to enhance the rooting of cuttings is to use rhizobacterial preparations. The aim of this study was to characterise rhizobacterial communities of Eucalyptus hybrid and species and identify possible plant-growth promoting rhizobacteria (PGPR). Materials and methods: Rhizospheric samples were collected from Eucalyptus hybrids and species. The rhizobacterial communities were characterised using fatty acid methyl esters (FAME) analysis and denaturing gradient gel electrophoresis (DGGE). DGGE fragments were further sequenced to identify rhizobacteria. Results and discussion: FAME analysis successfully achieved a broad characterisation of the Eucalyptus hybrid and species rhizobacterial communities based on their fatty acid composition. Myristic acid (C14:0) was the most abundant fatty acid. DGGE profiles gave a molecular profile of the Eucalyptus hybrid and species rhizobacterial communities based on their DNA composition. Nitrosomona eutropha was present in all samples which illustrates a nitrogen-rich environment. Adhaenbacter aquaticus was unique to the better rooting Eucalyptus hybrid GU111. Conclusion: This study provided some insight into the diversity of rhizobacterial communities of Eucalyptus hybrids and species. Possible PGPR were identified and the observation made that the nature of the soil environment changes with the aging of the associated host. These findings allow further investigation into the formulation of potential rhizobacterial preparations for rooting enhancement of Eucalyptus cuttings.
35

Influence of stockplant management on yield and subsequent rooting of cuttings of cold-tolerant Eucalyptus grandis x E. nitens clones.

Ziganira, Matabaro. January 2012 (has links)
Clones of the Eucalyptus grandis x Eucayptus nitens (GN) hybrids were produced and selected through the CSIR‟s breeding programmes for colder plantation sites in South Africa. Some GN clones consistently exhibit high and superior pulp properties, which makes them valuable for commercial plantations in South Africa. In nurseries, stockplants are usually seven cm in length and maintained at high (100 x1.5 m-2) planting density. However, rooting frequency varies with season and little is known about the impact of position of cuttings on overall rooting frequency of a clone. The aim of this study was to investigate the effect of size and planting density of stockplants in mini-hedges, on the yield and subsequent rooting of cuttings from various positions of GN clones of known rooting potential (i.e. GN 018B: difficult-to-root and PP 2107: easy-to-root clones). Stockplants (10 cm vs. 20 cm) were established at high (100 x 1.5 m-2) and at low (25 x 1.5 m-2) densities for GN 018B and PP 2107 under commercial nursery conditions in a polyethylene tunnel. Cuttings were harvested every two to three weeks in September-October 2010 (spring), December 2010-January 2011 (summer), April-May 2011 (autumn) and June-July 2011 (winter). The harvested material was 5 – 7 cm in length and the light intensity received by individual stockplants at the two planting density levels was recorded. Harvested cuttings from the three positions (apical, middle and basal shoots) were used for: (i) rooting experiments under nursery conditions, (ii) bio-stimulant analysis using the mung bean bioassay, and (iii) analysis of soluble sugars. Between spring and summer 2010, the two GN clones established at low density yielded a similar number of cuttings, but differences in the rooting frequencies were significant in favour of PP 2107 clone. Similar observations were made at high density in terms of production of cuttings, but the significant differences in the rooting observations were reversed between the clones. The GN 018B clone had low rooting rates in summer under nursery conditions but its tissue extracts promoted higher rooting in the bioassay during that time, when compared to spring. Spring and summer had similar effects on rooting responses of PP 2107 cuttings in nursery and bioassay experiments. For both clones, short stockplants produced fewer cuttings but had a higher rooting frequency than cuttings from tall stockplants, with a high rooting frequency recorded from basal cuttings. Similar results were observed in the bioassay experiments which showed high rooting potential of mung bean hypocotyls cuttings using tissue extracts of PP 2107 cuttings maintained at high planting density. Although apical cutting tissues had high concentration of sugars (i.e. sucrose, glucose and fructose), their rooting rates were usually lower at high and low planting density compared to middle and basal cuttings. Sucrose concentration was the highest sugar present in stockplants grown under low planting density. A higher and lower rooting frequency was also observed in autumn although the two clones responded differently to Quambalaria eucalypti (Sporothrix eucalypti) disease infestations. Position, size and genotype had a significant impact on type and concentration of sugar (i.e. sucrose, glucose and fructose), particularly in PP 2107 clone, although rooting rates in the bioassay did not correlate with sugar contents of Eucalyptus cuttings. High carbohydrate (i.e. soluble sugar) content and auxin concentration increased production and subsequent rooting of cuttings across both clones, particularly in spring. Furthermore, rooting was enhanced by relatively higher light intensity intercepted by individual stockplants and in particular the GN 018B clone. Light intensity in the high and low planting densities caused variation in the rooting frequencies thereby increasing or decreasing soluble sugar and auxin concentrations of the two clones. Light intensity and fertiliser concentration received by tall and short stockplants impacted on endogenous hormone levels thereby increasing or decreasing rooting. High sugar concentration levels of PP 2107 clone increased its susceptibility to fungal infection thereby decreasing its rooting frequency in autumn, as its rooting rates increased in winter. Overall results of the investigation revealed that PP 2107 clone has higher rooting potential than GN 018B clone, in particular at high planting density and if stockplants are not infected by fungal diseases. Higher sugar levels were recorded in spring for PP 2107, although rooting rates of mung bean hypocotyl cuttings were higher in summer for GN 018B, suggesting that sugars have nothing to do with rooting of GN cuttings. Season, planting density and size of stockplants affect the rooting frequency of GN clone. Thus, short stockplants maintained at low and high planting densities are recommended for GN 018B and PP 2107 respectively, although the impacts of fertilisers and pathogen resistance on rooting rates still need to be investigated under similar conditions. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

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