Estimativa de parâmetros genéticos, correlações fenotípicas e ambientais no girassol do cerrado do Distrito Federal.

RESUMO: O propósito deste trabalho foi avaliar a estima - tiva de parâmetros genéticos, correlações fe - notipicas e ambientais no girassol do Cerrado do Distrito Federal. Os caracteres analisados foram: rendimento de grãos, tamanho do ca - pítulo, peso de mil aquênios, altura de plantas e dias para floração inicial. Foram constatadas diferenças altamente significativas entre os ge - nótipos para todas as características morfoa - gronômicas avaliadas. Para o coeficiente CVr a maioria dos valores foram superior a 1 nos dois anos considerados, indicando que para a maioria dos caracteres aferidos há a possibi - lidade de êxito na seleção fenotípica uma vez que a variância genética superou a ambiental. Na herdabilidade, a maior estimativa verifica - da foi para o caráter PMA (98,76%) em 2013 e para DFI (99,68%) em 2014. Foram cons - tatadas diferenças altamente significativas en - tre os genótipos para todas as características morfoagronômicas avaliadas. O alto coeficiente de variação genético destaca a possibilidade de obter ganhos genéticos para todas as caracte - rísticas analisadas salvo em tamanho de capi - tulo. Materiais genéticos com potencial para as características agronômicas pesquisadas foram identificados no trabalho, podem ser indicadas ao sistema de produção irrigado no Cerrado. abstract: The purpose of this study was to estimate ge - netic parameters, phenotypic and environmen - tal correlations in sunflower of Brazilian savan - nah. The characters analyzed were: grain yield, chapter length, weight of a thousand achenes, plant height and days to start flowering. Hi - ghly significant differences were observed among genotypes for all morphoagronomic cha - racteristics evaluated. For the most CVr coe - fficient values were higher than 1 in the two years under consideration, indicating that for the majority of measured characters there is the possibility of successful phenotypic selection once the genetic variance exceeded the envi - ronmental. The heritability estimate was the hi - ghest for the PMA character (98,76%) in 2013 and DFI (99,68%) in 2014. Highly significant differences were observed among genotypes for all morphoagronomic characteristics evalu - ated. The high coefficient of genetic variation show the possibility of obtaining genetic gain for all examined characteristics except in chap - ter length. Genetic material with potential for the researched agronomic characteristics were identified in the work, can be indicated to the irrigated production system in the Brazilian sa - vannah.

Effect of inclusion or non-inclusion of short lactations and cow and/or dam genetic group on genetic evaluation of Girolando dairy cattle.

The objective of this study was to evaluate the effects of inclusion or non-inclusion of short lactations and cow (CGG) and/or dam (DGG) genetic group on the genetic evaluation of 305-day milk yield (MY305), age at first calving (AFC), and first calving interval (FCI) of Girolando cows. Covariance components were estimated by the restricted maximum likelihood method in an animal model of single trait analyses. The heritability estimates for MY305, AFC, and FCI ranged from 0.23 to 0.29, 0.40 to 0.44, and 0.13 to 0.14, respectively, when short lactations were not included, and from 0.23 to 0.28, 0.39 to 0.43, and 0.13 to 0.14, respectively, when short lactations were included. The inclusion of short lactations caused little variation in the variance components and heritability estimates of traits, but their non-inclusion resulted in the re-ranking of animals. Models with CGG or DGG fixed effects had higher heritability estimates for all traits compared with models that consider these two effects simultaneously. We recommend using the model with fixed effects of CGG and inclusion of short lactations for the genetic evaluation of Girolando cattle.

Estimates of genetic parameters using RELM/BLUP for intrapopulational genetic breeding of Platonia insignis Mart.

The aim of this study was to estimate genetic parameters to support the selection of bacuri progenies for a first cycle of recurrent selection, using the REML/BLUP (restricted maximum likelihood/best linear unbiased prediction) procedure to estimate the variance components and genotypic values. Were evaluated twelve variables in a total of 210 fruits from 39 different seed trees, from a field trial with an experimental design of incomplete blocks with clonal replies among subplots. The three variables related with the fruit development (weight, diameter, length) showed strong correlation, and where fruit length showed higher heritability and potential to be used for indirect selection. Among the 39 progenies evaluated in this study, five present potential to compose the next cycle of recurrent selection, due they hold good selection differential either to agrotechnological variables as to development of bacuri fruit.