Adaptabilidade e estabilidade produtiva de linhagens de soja na Macrorregião sojícola 3, Brasil.

O objetivo deste trabalho foi avaliar a adaptabilidade e estabilidade de 25 genótipos de soja (21 linhagens experimentais e 4 cultivares testemunhas), de ciclo precoce, avaliados em oito locais dentro da Macrorregião sojícola 3 (301, 302, 303 e 304), na safra 2010/2011. Para isso, utilizou-se a análise AMMI (modelo de efeitos principais aditivos e interação multiplicativa), aplicada a dados de rendimento de grãos de ensaios delineados em blocos casualizados, com quatro repetições. Todos os sete eixos principais da análise (IPCAs) estiveram relacionados ao padrão da interação de genótipos com ambientes (GxA), segundo a significância das respectivas somas de quadrados. Com isso, não houve descarte de ruído adicional, além daquele associado ao erro experimental médio, no ajuste das médias de tratamentos (genótipos) e das estimativas de interação GxA. As linhagens G20, G8, G21 e as testemunha G23 e G24 foram as mais estáveis e com boas médias de produtividade (adaptabilidade geral). O ambiente A2 (Rio Verde) foi o mais favorável à manifestação da produtividade dos genótipos, e o ambiente A6 (Itumbiara), aquele com as piores produtividades

AMMI & GGE BIPLOT: uma análise comparativa da avaliação de locais de teste de genótipos de arroz.

Ensaios de Valor de Cultivo e Uso (VCU) são de grande importância no melhoramento de plantas. A análise desses experimentos é comumente realizada utilizando-se diversas ferramentas estatísticas. Entre estas, nos últimos anos tem ganhado aplicação crescente análises como AMMI (Additive Main effects and Multiplicative Interaction) e GGE biplot (Genotype main effects and Genotype x Environment interaction effects)

Relevance of additive and non-additive genetic relatedness for genomic prediction in rice population under recurrent selection breeding

In genomic recurrent selection programs of self-pollinated crops, additive genetic effects (breeding values) are effectively relevant for selection of superior progenies as new parents. However, considering additive and nonadditive genetic effects can improve the prediction of genome-enhanced breeding values (GEBV) of progenies, for quantitative traits. In this study, we assessed the magnitude of additive and nonadditive genetic variances for eight key traits in a rice population under recurrent selection, using marker-based relationship matrices. We then assessed the goodness-to-fit, bias, stability and accuracy of prediction for breeding values and total (additive plus nonadditive) genetic values, in five genomic best linear unbiased prediction (GBLUP) models, ignoring or not nonadditive genetic effects. The models were compared using 6174 single nucleotide polymorphisms (SNP) markers from 174 S1:3 progenies evaluated in field yield trial. We found dominance effects accounting for a substantial proportion of the total genetic variance for the key traits in rice, especially for days to flowering. In average of the traits, the component of variance additive, dominance, and epistatic contributed to about 34%, 14% and 9% for phenotypic variance. Additive genomic models, ignoring nonadditive genetic effects, showed better fit to the data and lower bias, in addition to greater stability and accuracy for predict GEBV of progenies. These results improve our understanding of the genetic architecture of the key traits in rice, evaluated in early-generation testing. Clearly, this study highlighted the advantages of additive models using genome-wide information, for genomic prediction applied to recurrent selection in a self-pollinated crop

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu