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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

Varietal Loblolly (Pinus Taeda L.) Response to Various Management Schemes and Comparison among Genetic Improvement Levels

Herrin, Billy Landis 11 August 2012 (has links)
Increased growth rates, wood quality, and disease resistance have been accomplished within loblolly pine (Pinus taeda L.) through genetic selection and improved management practices. Genetic engineering of trees has the potential to further improve these selections but also needs to be tested. Two studies were conducted. Study one compares three levels of genetic improvement: Mass-Control Pollinated (MCP), Second Generation Op (2nd gen), and Varietal Material. After three years the MCP material had larger mean heights, mean diameters, and mean volume than the other two genetic entities. However the top five performing varietals were about 0.5 feet taller than the MCP material. Study two tested two contrasting loblolly pine ideotypes across different spacings and management intensities. After two years the crop tree ideotype and the intensive management plots had larger mean heights, mean ground-line diameters, mean volumes, and mean crown widths. Mean branch angle differed significantly between the two crown ideotypes.
2

Compatibilidade reprodutiva e micropropagação de ameixeiras japonesas. / Reproductive compatibility and micropropagation of Japanese plum.

Bandeira, Juliana de Magalhães 09 April 2010 (has links)
Made available in DSpace on 2014-08-20T14:22:09Z (GMT). No. of bitstreams: 1 Tese_Juliana_Magalhaes_Bandeira.pdf: 1698906 bytes, checksum: 40fa28ef99ce7cee9d0955c4f8688cdf (MD5) Previous issue date: 2010-04-09 / The Japanese plum (Prunus salicina Lindl.) has an important role in the horticulture worldwide. It has great importance in Brazilian market and is gaining fans for its production, especially in Rio Grande do Sul and Santa Catarina where winter conditions are propicious to its cultivation. However, there are some problems faced by farmers and breeders, which limit the increase in domestic production of plum trees, among these, there are the gametophytic self-incompatibility, due to the presence of a codominant multi-site (containing the so-called S-alleles) and susceptibility to Xillela fastidiosa Wells, which affects quality of propagation material. In face of these problems, the objective of this work was to identify physiologically Salleles of six cultivars of Japanese plum and develop a micropropagation protocol for the cv. America. Thus, experiments of controlled pollination were carried out in experimental fields at Embrapa Clima Tempreado (Pelotas/RS) and the in vivo pollination were carried out in the laboratory of six cup cultivars of Japanese plum (America, Rosa Mineira, Pluma 7, Amarelinha, Reubennel and Santa Rosa), to evaluate the fruit set and pollen tube growth (CTP), respectively. Additionaly, were also performed experiments of micropropagation in the Laboratory of Plant Tissue Culture (UFPel/RS) to identify an appropriate protocol for micropropagation of cv. America. In studies of reproductive compatibility, the fruit set was very low for all crosses, with the larger value had occur in the autopollination of 'Reubennel' (8.41%). 'America' only formed fruit when pollinated with the cvs. Rosa Mineira, Amarelinha, Santa Rosa and Reubennel, these last one had mutual compatibility with cv. America. 'Amarelinha' and 'Rosa Mineira' proved to be compatible with the pollen of 'Rosa Mineira' and 'Reubennel'. There was significant interaction for CTP level and pollen used to pollinate each female parents, and the crosses between 'America' x 'Pluma 7' and 'Rosa Mineira' x 'Santa Rosa' were incompatible while cv. America is self-incompatible. Some crosses that showed no pollination and fruiting in the field, hit the egg (level 6) or ovary (level 5) during in vivo pollination, such as 'Reubennel' x 'Rosa Mineira', 'Rosa Mineira' and 'Amarelinha' x 'America' and 'Amarelinha' and 'Pluma 7', and 'Santa Rosa' x 'America'. These results, together with the molecular data of S-alleles, allow a better understanding of the reproductive biology of P. salicina. In the micropropagation experiments we found that the in vitro establishment of basal 11 explants of cv. America in MS medium is higher than the apical explants. BAP concentrations between 0.25 and 0.50mg dm-3 are more appropriate for the multiplication while MS medium supplemented with 1.0mg dm-3 GA3 and 2.0g dm-3 of vegetal charcoal is the most appropriate to in vitro elongation of their shoots. Half of concentration of salts and vitamins of MS medium with the addition of 1.0mg dm-3 of IBA is the most efficient for the in vitro rooting of Japanese plum, cv. America, during periods of less than 20 days, reaching 88% survival after 30 days of acclimatization. / A ameixeira japonesa (Prunus salicina Lindl.) tem papel de destaque na fruticultura mundial. Possui grande importância no mercado brasileiro e vem ganhando adeptos à sua produção, principalmente no Rio Grande do Sul e Santa Catarina onde as condições de inverno favorecem o seu cultivo. Porém, existem alguns problemas enfrentados pelos produtores e melhoristas que limitam o aumento da produção nacional de ameixeiras, entre esses, destacam-se a autoincompatibilidade gametofítica, devido à presença de um loco multialélico (contendo os denominados alelos-S) e a suscetibilidade à Xillela fastidiosa Wells, que afeta a qualidade do material propagativo. Frente a esses problemas, o objetivo da realização deste trabalho foi identificar fisiologicamente os alelos-S de seis cultivares de ameixeira japonesa e desenvolver um protocolo de micropropagação para a cv. América. Desta forma, foram realizados experimentos de polinização controlada nos campos experimentais da Embrapa Clima Temperado (Pelotas/RS) e polinização in vivo, em laboratório, de seis cultivares copa de ameixeira japonesa (América, Rosa Mineira, Pluma 7, Amarelinha, Reubennel e Santa Rosa), onde foram avaliados a frutificação efetiva e o crescimento do tubo polínico (CTP), respectivamente. Também foram realizados experimentos no Laboratório de Cultura de Tecidos de Plantas (UFPel/RS), visando identificar um protocolo adequado para a micropropagação da cv. América. Nos estudos de compatibilidade reprodutiva, a frutificação efetiva foi muito baixa para todos os cruzamentos, sendo observado maior valor na autopolinização da Reubennel (8,41%). América somente apresentou frutificação quando polinizada com as cvs. Rosa Mineira, Amarelinha, Santa Rosa e Reubennel, sendo que essa última apresentou compatibilidade mútua com a cv. América. Amarelinha e Rosa Mineira mostraram-se compatíveis com o pólen da Rosa Mineira e Reubennel . Houve interação significativa para o grau de CTP e o pólen utilizado para polinizar cada um dos genitores femininos, sendo que os cruzamentos entre América x Pluma 7 e Rosa Mineira x Santa Rosa foram incompatíveis enquanto que a cv. América apresentou-se autoincompatível. Alguns cruzamentos que não apresentaram polinização e frutificação no campo, atingiram o óvulo (grau 6) ou o ovário (grau 5) durante a polinização in vivo, tais como Reubennel x Rosa Mineira ; 9 Rosa Mineira e Amarelinha x América e Amarelinha e Pluma 7 , e Santa Rosa x América . Estes resultados, juntamente com os dados moleculares dos alelos-S, permitem um melhor entendimento a respeito da biologia reprodutiva de P. salicina. Nos experimentos de micropropagação verificou-se que o estabelecimento in vitro de explantes basais da cv. América em meio MS, é superior ao de explantes apicais. Concentrações de BAP entre 0,25 e 0,50mg dm-3 são mais adequadas para sua multiplicação enquanto que o meio MS suplementado com 1,0mg dm-3 de AG3 e 2,0g dm-3 de carvão vegetal é o mais adequado para o alongamento in vitro de suas brotações. A metade da concentração dos sais e vitaminas do meio MS com a adição de 1,0mg dm-3 de AIB é o mais eficiente para o enraizamento in vitro de brotações de ameixeira japonesa, cv. América, por períodos inferiores a 20 dias, atingindo 88% de sobrevivência após 30 dias de aclimatização.

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