Diversidade e estimativas de parâmetros genéticos em mandioca (Manihot esculenta Crantz), oriunda de Moçambique

• Ano de defesa: 2013
• Autor(a) principal: Avijala, Matoso Francisco
• Orientador(a): Bhering, Leonardo Lopes
• Banca de defesa: Silva, Felipe Lopes da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Diversidade; Manihot esculenta Crantz; Parâmentros genéticos; Melhoramento genético
• Palavras-chave em Inglês: Diversity; Manihot esculenta Crantz; Genetic parameters; Breeding
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA QUANTITATIVA
• Link de acesso: http://locus.ufv.br/handle/123456789/4794

The genetic diversity and estimates of genetic and phenotypic parameters, such as genetic and phenotypic variances, heritability coefficients, genetic and phenotypic correlation coefficients, have great importance in breeding programs, as they allow making decisions related to the choice of the parents and the most appropriate method and the traits should be selected in initial and advanced stages of program and also the weight that should be assigned to each characteristics, separately or in combination. The objective of this work was to study the genetic diversity among cassava genotypes from Mozambique through multivariate techniques, and to estimate genetic and phenotypic parameters and genetic correlations for the traits evaluated in genotypes, thus aiming to generate knowledge that will give grants of choice strategies for genetic crop breeding. An experiment was carried out on the experimental field of IIAM in Mogincual district, in Mozambique, in the 2011/12 agricultural year. A randomized block design with twenty-one genotypes planted in three replications was adopted. The following traits were evaluated: plant height (ALTPL), height of the first branch (ALTPR); biomass weight (BIOPA), roots number per plant (NURPL), fresh root yield (RENRA); commercial root production (PRACO), harvest index (INDCO) and dry matter content (MATES). Statistical analyzes were performed using GENES software. The following genetic parameters were estimated: phenotypic (σ 2f), genotypic (σ2g) and environmental (σ2e) variances, heritability (h2), genetic coefficient variance variance/experimental (CVg), the coefficient ratio between variance the (CVg/CVe), genetic phenotypic coefficient (rf) and genotypic (rg) correlations and expected gains from selection. Genetic divergence was expressed through multivariate statistical consisting through Mahalanobis distance grouping the genotypes by Tocher and UPGMA methods. In additional the graphical method for canonical variables was used. After estimating the diversity concludes that there is divergence between the genotypes and some can be selected to participate in breeding programs such as MzMg10/096, MzMg10/630, MzMg10/240, MzMg10/314 and MzMg10/162. The ratio between the CVg/CVe presented estimates above 1 for the all traits, except for INDCO and MATES. These same traits exhibited high values for heritability. It was possible to identify strong genetic correlations between the following traits, BIOPA vs. RENRA (0,85) and NURPL vs. RENRA (0,94). There is a higher probability of gains for fresh root yield through indirect selection of BIOPA and NURPL traits. The genotypic correlations were higher than the phenotypic correlations in all cases, indicating that genetic factors contributed more than the environment for correlations.