Estudos genéticos em populações de Coffea canephora e Manihot esculenta

• Autor(a) principal: Giles, João Antonio Dutra
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/8216
• topic: Conilon coffee; Cassava; Plant breeding; Genetic divergence; Genetic parameters; Multivariate analysis; Café conilon; Mandioca; Melhoramento de plantas; Divergência genética; Parâmetros genéticos; Análise multivariada; Agronomia; 63

Know the genetic variability of a population, manifested through morphological and agronomic characters, is essential to guide its conservation and management, in addition to increasing the efficiency of breeding programs. After the characterization of the accessions, the study of genetic variability can be accomplished through of multivariate analyzes that are based on the differences between the materials, simultaneously integrating multiple information from the character set. In this way, also considering the socioeconomic importance of Coffea canephora and Manihot esculenta, the general objective was to carry out genetic studies in populations of both species. For this, two works were developed. The first, entitled "Divergence and genetic parameters among Coffea canephora genotypes", had as objective estimate the genetic parameters and to study genetic divergence in a population of C. canephora, using uni and multivariate statistical procedures, applied on a set of morphoagronomics characteristics (height and diameter of the plant; length between us of the orthotropic and plagiotropic branches; weight, volume and density of mature fruit; yield; productivity; chlorophyll index; length, width and leaf area; dry mass and specific dry mass of leaf). And the second, entitled "Agronomic characterization and genetic divergence among Manihot esculenta genotypes grown in Espírito Santo, had as objective was to perform the morpho-agronomic characterization and to study a genetic divergence among 12 genotypes of M. esculenta, using uni and multivariate statistical procedures, applied on a set of morphoagronomics characteristics (number of tuberous roots per plant; average weight of tuberous roots; productivity; total plant weight; harvest index; plant height; height of the first branch; number of shoots; stem diameter; number of buds; average sheet weight; petiole length). The two experiments were conducted in the municipality of Vila Valério - ES, where the genotypes were arranged in the experimental design of randomized blocks, with four replicates. Significant differences were detected by the F test at 1% or 5% probability among the genotypes for characteristics evaluated, evidencing the heterogeneity in the genetic constitution of the studied populations, which is favorable to breeding, because it indicates the possibility of discriminating superior ix and promising individuals. For the population of C. canephora, it was verified: was verified that the phenotypic variance of most of the characteristics analyzed was predominantly due to genetic causes; based on the generalized distance of Mahalanobis, the most divergent combinations were obtained between genotypes 23 and 10 (256.43) and between 23 and 17 (250.09); the groupings by methods of optimization Tocher and hierarchical UPGMA were concordant, grouping the genotypes into three groups, similarly. Among the analyzed characteristics, the weight of the mature fruit (19.08%) and the productivity (15.50%) were the most efficient in explaining the dissimilarity among genotypes. And for the genetic materials of M. esculenta, it was verified: the genotypes 3 (Camuquem) and 11 (Goiás) were the most productive; the greatest genetic distances were obtained between genotypes 10 and 12 (222.37) and between 1 and 12 (208.63); both the method of optimization as the hierarchical, ordered the genotypes in four groups, similarly; the petiole length (22.86%) and the produtivity (19.20%) were the most efficient in explaining the dissimilarity among genotypes.