Predição de ganhos genéticos via modelos mistos em progênies de café Conilon.

Objetivou-se, neste trabalho, avaliar os ganhos genéticos preditos por meio de diferentes índices de seleção pela metodologia REML/BLUP, em cinco caracteres de interesse ao programa de melhoramento do café conilon do Incaper. Foram avaliadas 8 progênies de meios-irmãos, de ciclo de maturação precoce, média de duas safras, com três repetições, o que totalizou 1368 observações, utilizados os índices de seleção clássico, multiplicativo e com base na soma de postos. Avaliaramse, na época de colheita, as características tamanho dos grãos (TG), produtividade (PRO), porte (PT), vigor vegetativo (VIG) e grau de inclinação (GI). A população foi avaliada na Fazenda Experimental de Marilândia, região Noroeste do estado do Espírito Santo. As análises genético-estatísticas foram realizadas pelo programa Selegen - REM/BLUP. Verificou-se, a partir da análise dos parâmetros genéticos, um excelente potencial seletivo entre famílias, para todas as características avaliadas. O índice Mulamba e Mock foi o que mostrou maior eficiência de seleção entre famílias de meios-irmãos de café conilon.

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.

Forage peanut (Arachis spp.) genetic evaluation and selection.

Forage peanut improvement for use in grass?legume mixtures is expected to have a great impact on the sustainability of Brazilian livestock production. Eighteen cloned Arachis spp. ecotypes were evaluated under clipping in a Brazilian Cerrado region and results analysed using a mixed model methodology. The objective was to estimate genetic and phenotypic parameters and to select the best ecotypes based on selection index applied on their predicted genotypic value. The traits of total dry-matter (DM) and leaf DM yield presented moderate (0_30 < h2g < 0_50) to high (>0_50) broad-sense heritability, in contrast to the low genetic variability in nutritional quality-associated traits. Ecotypes of Arachis spp. contained average crude protein concentrations of 224 g kg _1 DM in leaves and 138 g kg _1 DM in stems, supporting the potential role of these species to overcome the low protein content in Cerrado pastures. The correlations between yield traits and traits associated with low nutritional value in leaves were consistently significant and positive. Genetic correlations among all the yield traits evaluated during the rainy or dry seasons were significant and positive. The ecotypes were ranked based on selection index. The next step is to validate long-term selection of grass?Arachis in combination with pastures under competition and adjusted grazing in the Cerrado region.

Predictive ability of Genomic Estimated Family Values (GEFV).

Genomic selection (GS) has been used to compute genomic estimated breeding values (GEBV) of individuals; however, it has only been applied to animal and major plant crops due to high costs. Besides, breeding and selection is performed at the family level in some crops. We aimed to study the implementation of genome-wide family selection (GWFS) in two loblolly pine (Pinus taeda L.) populations: i) the breeding population CCLONES composed of 63 families (5-20 individuals per family), phenotyped for four traits (stem diameter, stem rust susceptibility, tree stiffness and lignin content) and genotyped using an Illumina Infinium assay with 4740 polymorphic SNPs, and ii) a simulated population that reproduced the same pedigree as CCLONES, 5000 polymorphic loci and two traits (oligogenic and polygenic). In both populations, phenotypic and genotypic data was pooled at the family level in silico. Phenotypes were averaged across replicates for all the individuals and allele frequency was computed for each SNP. Marker effects were estimated at the individual (GEBV) and family (GEFV) levels with Bayes-B using the package BGLR in R and models were validated using 10-fold cross validations. Predicted ability, computed by correlating phenotypes with GEBV and GEFV, was always higher for GEFV in both populations, even after standardizing GEFV predictions to be comparable to GEBV. Results revealed great potential for using GWFS in breeding programs that select families, such as most outbreeding forage species. A significant drop in genotyping costs as one sample per family is needed would allow the application of GWFS in minor crops.

Caracterização morfoagronômica e avaliação de parâmetros genéticos de girassol em três núcleos rurais do Distrito Federal.

RESUMO: O objetivo deste trabalho foi estimar caracteres genéticos, fenotípicos e ambientais relacionados aos componentes de produção e caracteres agromorfológicos de girassol em três núcleos rurais do Distrito Federal. Os experimentos foram conduzidos nas áreas experimentais da Embrapa Cerrados, Planaltina, DF, Embrapa Produtos e Mercado, Recanto das Emas, DF e na Fazenda Agua Limpa, da Universidade de Brasília. Através dos resultados obtidos, foram verificadas diferenças significativas entre os genótipos de girassol nos três núcleos rurais do Cerrado para todas as características agronômicas avaliadas. Ainda, baixos coeficientes de variação ambiental para quase todas as características, exceto para o tamanho de capitulo, indicaram boa precisão experimental e altos valores de herdabilidade, coeficientes de variação genéticos e acurácia evidenciaram condições favoráveis à seleção dos materiais para as características agronômicas avaliadas. ABSTRACT: The purpose of this study was to assess genetic, phenotypic and environmental characteristics related to agro-morphological traits of sunflower in three rural centers of Distrito Federal. The experiments were conducted at the experimental areas of Embrapa Cerrados, Planaltina, DF, Embrapa Produtos e Mercado, Recanto das Emas, DF e na Fazenda Agua Limpa, da Universidade de Brasília. Through the obtained results, were verified significate genotypic differences of sunflower at the three rural centers of Brazilian Savannah for all traits evaluated. In addition, low coefficients of environmental variation for almost all trait, except the head size, indicate good experimental precision and high values of heritability, genetic variation and accuracy showed favorable conditions to selecting materials for the agronomic traits evaluated.