Crop Breeding and Applied Biotechnology
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/12091
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Resultados da Pesquisa
Item Prediction of selection gains in Coffea canephora based on factorial scores(Crop Breeding and Applied Biotechnology, 2004) Ferreira, Adésio; Cecon, Paulo Roberto; Cruz, Cosme Damião; Ferrão, Romário Gava; Silva, Marcia Flores da; Fonseca, Aymbiré Francisco Almeida da; Ferrão, Maria Amélia GavaThe technique of factor analysis in the simultaneous selection of traits and prediction of genetic gains was evaluated in Coffea canephora var. conilon. Fourteen traits in 40 assessed genotypes were evaluated at two sites. The technique was used aiming at the structuring and simplification of the data, without information loss and with biological interpretation. The experimental design was of randomized blocks in four replications, each plot containing two useful plants. The technique was efficient for the data simplification and structuring. Moreover, the estimates of the predicted gains in the traits involved in the factors showed magnitude near the direct selection gain, attesting the suitability of the technique and its use in improvement programs of the species.Item Repeatability and number of harvests required for selection in robusta coffee(Crop Breeding and Applied Biotechnology, 2004) Fonseca, Aymbiré Francisco Almeida da; Sediyama, Tocio; Cruz, Cosme Damião; Sakiyama, Ney Sussumu; Ferrão, Romário Gava; Ferrão, Maria Amélia Gava; Bragança, Scheilla MarinaThis study aimed to estimate the repeatability coefficient of the grain yield in Coffea canephora by three methods: to quantify the precision of the measurements; to predict the real value of an individual based on n evaluations; and to determine the number of phenotypic measures required in each plant to obtain an adequate precision level for an efficient discrimination of the genotypes. The coefficients of repeatability and determination were estimated based on four harvests of 80 genotypes. Highest estimates of the repeatability coefficient were obtained by the method of the principal components derived from the matrix of covariances, which expresses the correlation between each measurement pair. The prediction precision of the real individual value ranged from 65.32 to 81.59%, and remained practically unchanged from the sixth harvest on.Item Inter-trait relations for direct and indirect selection in coffee(Crop Breeding and Applied Biotechnology, 2008-06-09) Ferrão, Romário Gava; Ferreira, Adésio; Cruz, Cosme Damião; Cecon, Paulo Roberto; Ferrão, Maria Amélia Gava; Fonseca, Aymbiré Francisco Almeida da; Carneiro, Pedro Crescêncio de Souza; Silva, Marcia Flores daThe purpose of this study was to verify the possibility of using direct selection in nine traits underlying indirect selection for yield and determine which traits should participate in the selection process. Data of 40 Conilon coffee genotypes were analyzed in two experiments in the growing seasons of 1996, 1998, 1999, 2000 and 2001 in random blocks with four and six replications. The significance of phenotypic associations was evaluated by the t test and the genotypic and environmental associations by bootstrap resampling. The genotypic associations were higher than the phenotypic, indicating a prevailing influence of the genotypic over the environmental effects in the relationship between significant traits; equal signs indicated a lack of contrary action among the effects. The traits related to cycle; yield; ratio of fresh ripe cherries to clean coffee; empty or flat grains; and sieve 17 should be maintained in the selection, evaluation and study of genetic divergence. The estimated gains in grain yield by indirect selection for any trait studied are not satisfactory.Item Discriminant analysis for the classification and clustering of robusta coffee genotypes(Crop Breeding and Applied Biotechnology, 2004-07-07) Fonseca, Aymbiré Francisco Almeida da; Sediyama, Tocio; Cruz, Cosme Damião; Sakiyama, Ney Sussumu; Ferrão, Romário Gava; Ferrão, Maria Amélia Gava; Bragança, Scheilla MarinaThis study evaluated the adequacy of the composition of three clonal Coffea canephora varieties recommended for the State of Espírito Santo by a multivariate method designated discriminant analysis. This method consists in the establishment of functions that enable the classification of a given individual into one, among various distinct populations, reducing the probability of a misclassification. It simultaneously considers measures of several traits, in order to give the new variety homogeneity. The original classification of genotypes in the three studied varieties, based on agronomical criteria, maintained expressive concordance with the results of the discriminant analysis, with an apparent deviation rate of only 6.25%. Corrected discriminant functions were also proposed, capable of classifying a new genotype into one of the three clonal varieties to be used in improvement programs, eliminating the subjectivity of the clustering process.Item Genetic divergence in Conilon coffee revealed by RAPD markers(Crop Breeding and Applied Biotechnology, 2009) Ferrão, Maria Amélia Gava; Fonseca, Aymbiré Francisco Almeida da; Ferrão, Romário Gava; Barbosa, Wellington Marota; Souza, Elaine Manelli RivaThis study aimed to evaluate the genetic variability of 49 Coffea canephora clones of the breeding program of the Capixaba Institute of Research, Technical Assistance and Rural Extension (Incaper) based on RAPD markers. Thirty-one primers were used with polymorphism patterns that generated 333 markers, of which 231 (69.4%) were polymorphic. The group of genotypes based on the UPGMA algorithm and Tocher optimization methods detected high divergence in the genotypes. It was found that the component clones of each clone variety recommended by Incaper are distributed in various genetically dissimilar groups, in spite of common phenotypic traits. The relatively wide genetic diversity observed here demonstrates the importance of hybridizations between these germplasms. The RAPD markers efficiently estimated the genetic divergence in the 49 C. canephora genotypes studied.