ABSTRACT Identifying Coffea arabica cultivars that are more efficient in the use of nitrogen is an important strategy and a necessity in the context of environmental and economic impacts attributed to excessive nitrogen fertilization. Although Coffea arabica breeding data have a multi-trait structure, they are often analyzed under a single trait structure. Thus, the objectives of this study were to use a Bayesian multitrait model, to estimate heritability in the broad sense, and to select arabica coffee cultivars with better genetic potential (desirable agronomic traits) in nitrogen-restricted cultivation. The experiment was carried out in a greenhouse with 20 arabica coffee cultivars grown in a nutrient solution with low-nitrogen content (1.5 mM). The experimental design used was in randomized blocks with three replications. Six agromorphological traits of the arabica coffee breeding program and five nutritional efficiency indices were used. The Markov Chain Monte Carlo algorithm was used to estimate genetic parameters and genetic values. The agromorphological traits were considered highly heritable, with a credibility interval (95% probability): H2 = 0.9538 – 5.89E-01. The Bayesian multitrait model presents an adequate strategy for the genetic improvement of arabica coffee grown in low-nitrogen concentrations. Coffee arabica cultivars Icatu Precoce 3282, Icatu Vermelho IAC 4045, Acaiá Cerrado MG 1474, Tupi IAC 1669-33, Catucaí 785/15, Caturra Vermelho and Obatã IAC 1669/20 demonstrated greater potential for cultivation in low-nitrogen concentration.

ABSTRACT. The importance of rice (Oryza sativa) is indisputable this cereal is the staple food for half of the global population. Genetic progress estimation allows evaluation of the effectiveness of genetic improvement of crops and helps in the planning of breeding programs. This paper aims to estimate the genetic yield progress made by the program in the state of Minas Gerais, Brazil, which is run by the Epamig/UFV/Embrapa consortium. A total of 210 lines were evaluated by value for cultivation and use testing that was conducted in the municipalities of Janaúba, Leopoldina, and Lambari, from 1993 to 2016. Based on Vencovsky’s (1986) method, the genetic gains in Lambari, Janaúba, and Leopoldina were 1.46, 0.14, and 0.11%, respectively. The gain in Leopoldina was considered very low during the evaluated period. According to Breseghello’s (1998) method, the annual average genetic gain was 0.23 and 0.04% in Lambari and Janaúba, respectively. In Leopoldina, a yield gain of - 2.37% per year was observed for the evaluation period from 1994 to 1999, and a yield gain of 0.1% per year was observed from 2000 to 2016. These results can be explained by the focus on quality as a strategy for the breeding program in Minas Gerais State in the 1990s. Vencovsky’s (1986) and Breseghello’s (1998) methods were able to quantify yield gains and demonstrate the dynamics of the irrigated rice genetic improvement program in Minas Gerais State.

Abstract: The aim of this study was to obtain estimates of genetic parameters via meta-analysis and mixed models to evaluate the potential of the germplasm from Embrapa Pecuaria Sudeste for integration in breeding programs. Data on the dry matter yield of 77 accessions evaluated in 24 harvests were used. Descriptive analysis was performed for mixed model and meta-analytical estimates. The variances for each parameter were estimated. For the meta-analysis, variances were used as weighting measures, and the fixed and random models were tested. A diagonal structure was considered for the residual variance matrix. Mean dry matter yield ranged from 1019.5 to 2684 kg ha-1. The phenotypic, permanent environmental, and genotypic variances oscillated widely throughout the harvests, as well as heritability. Meta-analytical estimates proved to be an accurate and complementary approach to the mixed model analysis. Both mixed model and meta-analytical estimates indicated the breeding potential of the alfalfa germplasm.

ABSTRACT. This study presents self-organizing maps (SOM) as an alternative method to evaluate genetic diversity in plant breeding programs. Twenty-five genotypes were evaluated in two environments for 11 phenotypic traits. The genotypes were clustered according to the SOM technique, with variable topology and numbers of neurons. In addition to the SOM analysis, unweighted pair group method with arithmetic mean clustering (UPGMA) was performed to observe the behavior of the clustering when submitted to these techniques and to evaluate their complementarities. Genotype ordering according to SOM was consistent with UPGMA results, evidenced by the basic structure of UPGMA groups being preserved in each group of the maps. Regarding genotype arrangement and the group neighbors, maps involving five neurons presented inferior organization efficiency compared to the six-map arrangements in both environments. It was observed that the organization pattern among the rice genotypes evaluated by the maps was complementary to the UPGMA approach, as observed in all scenarios. It can be concluded that self-organizing maps have the potential to be useful for genetic diversity studies in breeding programs.

RESUMO O melhoramento genético da alfafa para alimentação animal leva mais tempo do que para muitas outras culturas. Por isso, definir melhores métodos de seleção é importante para o sucesso do melhoramento da cultura. Objetivou-se utilizar métodos de seleção direta, indireta e simultânea, para a seleção de cultivares de alfafa, com base em características de produção e valor nutritivo. As características avaliadas foram subdivididas em dois grupos: produção e valor nutritivo. Os ganhos de seleção foram estimados por seleção direta, indireta e simultânea para cada grupo, considerando-se a seleção das 25 % melhores cultivares. As seleções direta e indireta entre as médias dos genótipos não são eficientes para fornecer as respostas desejáveis para todo o conjunto de características. Os resultados da seleção simultânea, utilizando-se o índice de Tai, forneceram uma distribuição de ganhos mais equilibrada para os conjuntos de características em todos os cortes. A seleção simultânea permitiu a identificação das cultivares 5681 e Verdor no primeiro corte, bem como a ProINTA Patricia no segundo corte, como superiores, nos dois grupos de características avaliadas.

ABSTRACT Alfalfa breeding aimed at trait improvement for livestock feed takes longer periods of time, if compared to many other crops. Therefore, better selection methods are necessary for the success of alfalfa breeding programs. Although knowing about selection methods is quite important, there is a notable lack of information, as regards successful solutions. This study aimed to use direct, indirect and simultaneous selection methods for selecting alfalfa cultivars, based on yield traits and nutritive value. The evaluated traits were subdivided into two groups: forage yield and nutritive value. Selection gains were estimated by direct, indirect and simultaneous selection for each group, considering the selection of the 25 % best cultivars. Direct and indirect selections among genotype averages are not efficient to provide the desirable responses to the whole set of traits. The results for simultaneous selection, using the Tai index, provided a more balanced gain distribution to the set of traits in all cuts. The simultaneous selection allowed the identification of the 5681 and Verdor cultivars in the first cut, as well as ProINTA Patricia in the second cut, as superior in the two groups of evaluated traits.

Resumo Estudos que utilizam métricas baseadas em céu dinâmico para abordagem de desempenho de iluminação natural em recintos são raros em cidades de latitudes tropicais. Este estudo aplicou a métrica Autonomia Espacial de Luz Natural (sDA 300,50% ≥75%, IES LM 83-12) para Cuiabá (15ºS, 56ºW, Brasil), uma cidade de savana com predominância de céus parcialmente nublados. Simulações paramétricas foram utilizadas para investigar a disponibilidade de iluminação natural em contexto urbano adensado. As condições de iluminação natural dentro de um recinto de profundidade variada localizado em um cânion urbano foram simuladas com Radiance/Daysim no Grasshopper/Honeybee. Dimensões da via e de altura dos edifícios frontais foram variadas com o objetivo de observar a relação entre o ângulo de céu e o sDA para as quarto orientações solares principais. Os resultados deste estudo de caso mostraram que a profundidade do recinto tende a ser o parâmetro mais relevante entre os analisados para a otimização de iluminação natural interna. Finalmente, as limitações dessa abordagem e oportunidades de futuras pesquisas foram discutidas.

Abstract Studies using metrics related to dynamic sky conditions for indoor daylight performance assessment in urban environment are rare in tropical latitudes. This study applied one of these metrics, the spatial Daylight Autonomy (sDA 300,50% ≥75%, IES LM 83-12) for Cuiabá (15ºS, 56ºW, Brazil), a savanna climate city with a high frequency of partly cloudy skies. Parametric simulations were used to investigate the availability of daylight in dense urban areas. So daylight conditions inside a reference room with varied depths located within a continuous urban canyon were simulated with Radiance/Daysim in Grasshopper/Honeybee. Dimensions of the street and heights of front buildings (obstructions) are also varied in order to observe the relation between the sky angle and the sDA, for the four main cardinal directions. The results of regression analysis for this case study showed that among all evaluated parameters, room depth tended to be the most relevant for the optimization of indoor daylight. Finally, limitations of this approach and opportunities for further investigations were discussed.

O Regulamento Técnico da Qualidade para Eficiência Energética de Edifícios Comerciais, de Serviços e Públicos (RTQ-C) é a referência brasileira para avaliação de desempenho energético de edifícios. O presente trabalho enfoca a influência de proteções solares no desempenho de edifícios a partir deste documento. Para isto, o RTQ-C é aplicado a um projeto de edificação que não possui tais dispositivos. Proteções são então aplicadas ao edifício e o desempenho energético é calculado pelo método prescritivo do RTQ. Por simulação computacional, as mesmas proteções são inseridas em um ambiente-padrão do prédio e obtêm-se dados de consumo de energia total e com iluminação. Ao longo do estudo, discute-se os resultados obtidos pelo método prescritivo e por simulação com o objetivo de levantar considerações sobre a metodologia de análise de envoltória pelo Regulamento. Paralelamente, buscou-se avaliar o desempenho de brises e de prateleiras de luz dimensionados pelo método da Temperatura Neutra. Os principais resultados reforçam a importância de se considerar a geometria e a orientação solar dos dispositivos no desempenho, fatores que não são avaliados pelo RTQ-C prescritivo.

The Technical Quality Regulation on the Energy Efficiency of Commercial, Service and Public Buildings (RTQ-C) is the Brazilian reference for evaluating the energy performance of buildings. This study focuses on the influence of solar protection devices in building consumption based on this code. A building without solar devices is analysed under the prescriptive method of RTQ-C. Overhangs and lightshelves are designed for the building and the performance under RTQ-C is recalculated. Then, the same devices are applied to a room in the building. The total energy consumption of the room with and without solar devices is obtained through computer simulation. The results of this process are the basis for a discussion about the performance evaluation criterion of the prescriptive method of RTQ-C. The main results reinforce that the geometry and solar orientation of a device must be considered, although the prescriptive RTQ-C does not consider those aspects.