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RESUMOA obtenção de informações a respeito do controle genético dos caracteres por meio de variâncias com associação aos métodos de condução de populações de feijoeiro tem sido uma estratégia pouco empregada, porém pode ser de grande auxílio aos melhoristas na tomada de decisões. Com esse objetivo foi utilizada uma população segregante proveniente do cruzamento entre as cultivares BRS MG Talismã e BRS Valente. O avanço das gerações foi realizado de acordo com o preconizado pelo método genealógico. Em F 4:5 obtiveram-se 256 progênies que foram avaliadas na safra das águas 2004/2005. As sementes de cada progênie foram colhidas em bulk originando as progênies F 4:6 , as quais foram avaliadas na safra das secas 2005. Os caracteres avaliados foram produtividade de grãos e porte das plantas. Constatou-se que na produção de grãos por planta, a variância ambiental dentro da parcela foi o principal componente da variância fenotípica entre progênies. A variância genética aditiva foi predominante para a produção de grãos, enquanto que para o porte a variância genética de dominância foi expressiva. Termos para indexação:Phaseolus vulgaris, componentes de variância, método genealógico. ABSTRACTObtaining information referent to the genetic control of traits by the estimates of variance associated to breeding methods is not frequently used for bean crops, however these estimate can greatly help breeders to take decision. With this objective a segregating population derived from a cross between the cultivars BRS MG Talismã and BRS Valente was evaluated. The advance of generations was done according to the pedigree method. In the INTRODUÇÃOA obtenção de informações a respeito do controle genético dos caracteres auxilia os melhoristas na tomada de decisão. No caso dos caracteres quantitativos, essas informações podem ser obtidas utilizando componentes de média ou de variância (CRUZ et al., 2004). Os componentes da variância têm a vantagem de os efeitos genéticos não se anularem, como pode ocorrer com médias, e possibilitam também estimar a herdabilidade e o ganho esperado com a seleção.Há, na literatura, algumas informações sobre o controle genético de alguns caracteres do feijoeiro utilizando variâncias, sendo a maioria com a geração F 2 e retrocruzamentos (TEIXEIRA et al., 1999) e cruzamentos dialélicos (OTUBO et al., 1995;SANTOS, 1984). O ideal, contudo, é associar o programa de melhoramento com a obtenção de estimativas que auxiliem os melhoristas na tomada de decisões. Essa estratégia tem sido relativamente pouco empregada com a cultura do feijoeiro. Além do mais, a maioria dos trabalhos existentes utilizaram o método denominado de progênies derivadas de plantas F 2 (SOUZA & RAMALHO, 1995). A desvantagem desse procedimento é que as progênies são avaliadas em gerações diferentes, o que dificulta as estimativas dos componentes de média ou variância devido ao efeito da interação genótipos por ambientes. Acrescenta-se ainda que o coeficiente associado

The purpose of this study was to select Coffea arabica progenies for resistance to M. paranaensis in an infested coffee growing area using Henderson's mixed model methodology. Forty-one genotypes were selected at the Coffee Active Germplasm Bank of Minas Gerais, and evaluated in regard to stem diameter, number of plagiotropic branches, reaction to the nematode, and yield per plant. There was genetic variability among the genotypes studied for all the traits evaluated, and among the populations studied for yield and reaction to the nematode, indicating possibilities for obtaining genetic gains through selection in this population. There was high rate of genotypic association between all the traits studied. Coffee plants of Timor Hybrid UFV408-01 population, and F3 progenies derived from crossing Catuaí Vermelho and Amphillo MR 2161 were the most promising in the area infested by M. paranaensis.

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Potato (Solanum tuberosum L.) is one of the most important crops for human consumption worldwide, representing an essential component for the food security of several countries. However, yield and quality are negatively affected by biotic and abiotic stresses. In this sense, the selection of potato cultivars tolerant to heat and resistant to diseases is of great importance. Our goal was to select clones suitable for the chips industry, having heat tolerance and bearing the Rx1 and Ryadg alleles, which confer resistance to Potato virus X and Potato virus Y. We evaluated 491 clones originating from 31 biparental crosses under three different seasons in terms of heat stress (without heat stress [WHS], moderate heat stress [MHS], and high heat stress [HHS]). The evaluated traits were specific gravity (SG), dry matter yield (DMY), and proportion of physiological disorders (PD). After evaluation in the WHS and MHS seasons, the presence of the Rx1 and Ryadg alleles was investigated with the help of molecular markers in the 68 clones showing the best performance, which descended from the DGN2103 and DGN4002 parental clones. To gather the genotypic values for all traits in each season, the clones were ranked according to an index based on the genotype–ideotype distance. On average of all seasons, the top 10% selected clones by the index were 9 and 0.1% higher than the Atlantic cultivar for the traits DMY and SG, respectively, and 80% lower than Atlantic cultivar for PD. In conclusion, we report the selection of potato clones suitable for industrial processing.

ABSTRACT. Sweet sorghum has considerable potential for ethanol production due to its succulent stalks that contain directly fermentable sugars. Since many traits need to be considered in the selection process to breed superior cultivars for ethanol production, then correlations between the traits might be of use to help the breeder define optimal improvement strategies. The aim of this study was to investigate the association between the principal agro-industrial traits in sweet sorghum, and to evaluate the direct and indirect effects of primary and secondary traits on ethanol production per hectare. In total, 45 sweet sorghum genotypes (lineage/ hybrids) were evaluated in an experiment designed in an alpha lattice 5 x 9. The data were analyzed using a mixed model approach. A detailed study of simple correlations was accomplished using path analysis. The experimental precision was high, with an accuracy above 76%. The various genotypes showed genetic variation for all agronomic and industrial traits, except stalk diameter. Some agro-industrial traits showed significant simple 16393 Path analysis in sweet sorghum ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 16392-16402 (2015) correlations with ethanol production, but according to the path analysis, some of these traits did not show a significant direct or indirect effect on ethanol production. The results highlighted the primary and secondary traits with practical relevance to sweet sorghum breeding, since they showed director indirect effects on ethanol production.

Controlling spatial variation in agricultural field trials is the most important step to compare treatments efficiently and accurately. Spatial variability can be controlled at the experimental design level with the assignment of treatments to experimental units and at the modeling level with the use of spatial corrections and other modeling strategies. The goal of this study was to compare the efficiency of methods used to control spatial variation in a wide range of scenarios using a simulation approach based on real wheat data. Specifically, classic and spatial experimental designs with and without a two-dimensional autoregressive spatial correction were evaluated in scenarios that include differing experimental unit sizes, experiment sizes, relationships among genotypes, genotype by environment interaction levels, and trait heritabilities. Fully replicated designs outperformed partially and unreplicated designs in terms of accuracy; the alpha-lattice incomplete block design was best in all scenarios of the medium-sized experiments. However, in terms of response to selection, partially replicated experiments that evaluate large population sizes were superior in most scenarios. The AR1 $$\times $$ ×  AR1 spatial correction had little benefit in most scenarios except for the medium-sized experiments with the largest experimental unit size and low GE. Overall, the results from this study provide a guide to researchers designing and analyzing large field experiments. Supplementary materials accompanying this paper appear online.