Pavan B.E.,UFPI CPCE |
de Paula R.C.,Sao Paulo State University |
Perecin D.,Sao Paulo State University |
Candido L.S.,Laboratory Of Melhoramento Genetico Vegetal |
Scarpinati E.A.,Fibria S A Celulose Unidade Tres Lagoas
Scientia Agricola | Year: 2011
The effect of competition is an important source of variation in breeding experiments. This study aimed to compare the selection of plants of open-pollinated families of Eucalyptus with and without the use of competition covariables. Genetic values were determined for each family and tree and for the traits height, diameter at breast height and timber volume in a randomized block design, resulting in the variance components, genetic parameters, selection gains, effective size and selection coincidence, with and without the use of covariables. Intergenotypic competition is an important factor of environmental variation. The use of competition covariables generally reduces the estimates of variance components and influences genetic gains in the studied traits. Intergenotypic competition biases the selection of open-pollinated eucalypt progenies, and can result in an erroneous choice of superior genotypes; the inclusion of covariables in the model reduces this influence.
Ferreira R.T.,Laboratory Of Melhoramento Genetico Vegetal |
Viana A.P.,Laboratory Of Melhoramento Genetico Vegetal |
Barroso D.G.,Laboratory Of Fitotecnia |
de Resende M.D.V.,Federal University of Vicosa |
do Amaral Junior A.T.,Laboratory Of Melhoramento Genetico Vegetal
Scientia Agricola | Year: 2012
The increasing demand for raw material for multiple uses of forest products and by-products has attracted the interest for fast growing species, such as the Australian Cedar (Toona ciliata), which presents high productive and economic potential. This study aimed at estimating genotypic parameters and values for the species through the use of the BLUP procedure, at individual level, with repeated measures, by means of the conventional evaluation procedures and the introduction of innovative digitalization of the measurements by digital camera with the images provided by the Imagej software system. The main objective is to subsidize the beginning of a breeding program for the species. The assays were carried out in private properties, in plantations located in the state of Rio de Janeiro, Brazil. The results generated by three evaluations revealed that the image digital analysis is adequate to quantify characteristics of Toona ciliata. It is also an effective and accurate alternative to minimize the costs of data collection in evaluations with the species. There was high accuracy for the characters plant height, diameter at breast height and cylindrical volume. Out of the 90 genotypes evaluated, 38 expressed genotypic values predicted for the diameter at breast height higher than the general average of this character, 33 for the cylindrical volume and 49 for height, allowing gains of up to 24.9% in average for cylindrical volume. The method of mixed models (REML/BLUP) applied via the SELEGEN software system, using the BLUP procedure at individual level and repeated measures in each individual proved to be adequate to estimate the genetic parameters and predict genotypic values in situations of unbalanced data. Therefore, it is very useful and practical for Toona ciliata genetic breeding programs.
Agronomic potential and genetic divergence among eggplant genotypes in the Colombian Caribbean region [Potencial agronômico e divergência genética entre genótipos de berinjela nas condições do Caribe Colombiano]
Aramendiz-Tatis H.,University of Cordoba, Colombia |
Sudre C.P.,Laboratory Of Melhoramento Genetico Vegetal |
Goncalves L.S.,Laboratory Of Melhoramento Genetico Vegetal |
Rodrigues R.,Laboratory Of Melhoramento Genetico Vegetal
Horticultura Brasileira | Year: 2011
We evaluated 24 genotypes (hybrids, cultivars and landraces) of eggplant related to yield traits in the Colombian Caribbean region, to quantify the genetic divergence among these genotypes and to indicate possible crosses. With the results of the genetic diversity and agronomic traits we intend to initiate a program of eggplant breeding in that region. A randomized block design with three replications was used. The analyzed variables were fruit length, number of fruits per plant, mean fruit weight, yield, fruit firmness and plant height. The data were submitted to variance analysis and the averages grouped by Scott-Knott test. A multivariate analysis was also performed using different methods of hierarchical clustering and canonical variables. There was high divergence among the studied genotypes even when considered within hybrids, cultivars and landraces, with highest variability among the cultivars and hybrids followed by the landraces. The UPGMA method was more reliable than Ward and Single Linkage methods since UPGMA presented greater value of Cophenetic Correlation Coefficient (CCC). Using pseudo-F and pseudo-t2 criteria the maximum point was reached when four clusters were formed, being considered the ideal number of groups for the UPGMA. There was agreement among the groups formed for UPGMA analysis and canonic variables. Crosses between CC08 × CC02; CC08 × EU01 and CC08 × C016 may be recommended to start an eggplant breeding program aiming to improve yield and fruit firmness.