Efeito da competição dentro de parcelas, da interação genótipos x ambientes e influência de estratégias de seleção no melhoramento genético de eucalipto

• Autor(a) principal: Pinto, Danielle Silva
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4721
• topic: Variação genética dentro de parcelas; Interação genótipo por ambiente; Ganhos por seleção; Genetic variation within plots; Genotype by environment interactions; Selection gains; CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA QUANTITATIVA

The aim was to determine the genetic parameters of progeny tests in Eucalyptus grandis Hill Maiden with 3 years old under competicional effect, as well as to study the genotype x environment interaction and its impact on strategies for direct and indirect selection and analyze different selection strategies like selection among and within, mass, stratified mass selection and combined selection in three different locations of the Company Jari Celulose S/A. The experimental design was a randomized block with 93 half-sib progenies, 10 replications, linear plots of five plants and spacing of 3m x 2m. The evaluated characteristics were height (ALT), in meters, diameter at breast height (DBH) in cm and the volume (VOL) in m3. It were estimated selection gains with a percentage of 20% between half-sib and 40% within, the same being maintained for all selection strategies analyzed. It was detected high plants mortality in the experiments, which interfered with the accuracy of the experiments. The progeny tests showed genetic variability, with greater variability within plots. It was also detected competicional effect observed by the negative intraclass correlation among plants within plots. Its existence interfered in the estimates of phenotypic variance within plots and environmental variance. In the interaction study were found significant effects for genotypes and also for the genotype x environment interaction, showing variability among progenies and differential behavior along these different environments. Regarding to the analised places, local 2 and 3 showed no significant interaction. The site has major direct gain and maximized the gain for the other two locals was the local 2. To analyze the selection gain with different strategies such as selection among and within, mass selection, stratified mass selection and combined selection, the analysis were done only with DAP, because of its high correlation with other variables. The combined selection strategy showed superior results to the selection processes among and within, mass and stratified with percentages estimates ranging from 6.67% to 18.67%.