Abstract The viability of using inbred progenies, i.e., S1 or S2, in recurrent selection programs for perennial plants was evaluated in comparison with full sibs using the expression of gain from selection. Populations with different genetic properties, were considered in obtaining the estimates, with the population genetic variance always equal to 1 used as reference, as well as different experimental strategies. The estimates of genetic covariances between average additive effects of the alleles and the dominance effects of homozygotes, which occur when S1 or S2 is used, although negative for the lower values of the average allele frequencies, were always smaller than the additive genetic variance. Per unit of time, the total gain from selection with S1 was greater than with S2 and full sibs. However, it is argued that the best strategy is a cycle with S1, followed by a cloned progeny test with full sibs.

Abstract We aimed to measure the efficiency of visual selection of plant vigor for green biomass production of U. ruziziensis using single- and multitrait approaches to maximize the predictive accuracy of the genetic value. The green biomass production and plant vigor of 254 U. ruziziensis clones were measured over nine evaluation cuttings to determine the efficiency of these approaches for production improvement. Individual and multicutting analyses were performed under single-trait and multitrait approaches using mixed models. The efficiency of visual selection was assessed by measuring plant vigor based on direct and indirect genetic gains. Plant vigor showed a high genetic association with green biomass and could be selected for production, especially in the initial phases of breeding programs. The multitrait approach was superior to the single-trait approach in predicting the genetic value of the clones, and it can be used in U. ruziziensis breeding programs.

Resumen El propósito de este estudio fue identificar el tamaño de muestra ideal que representa a una familia en su potencial, identificar familias superiores y, en paralelo, determinar qué disposición espacial puede tener una mayor precisión en cuanto a la selección de nuevas variedades de caña de azúcar. Para tal fin, se evaluaron cinco familias de hermanos completos, cada una con 360 individuos, en diseño de bloques al azar, con tres repeticiones y tres distancias diferentes entre las plantas en una misma hilera (50 cm, 75 cm y 100 cm). Se mantuvieron 150 cm entre hileras. Para determinar el tamaño ideal de la muestra, así como la mejor distancia para la evaluación, se adoptó el método bootstrap. Se observó que distancias de 100 cm resultaron en el mejor valor promedio de números de tallo, diámetro del tallo y peso estimado de los tallos en las heces. La separación de 75 cm entre las plantas permitió un mejor poder de discriminación entre las familias para todos los caracteres evaluados. Con 75 cm también fue posible identificar familias superiores con una muestra de 30 plantas en cada parcela y 3 repeticiones en el ensayo.

Abstract The purpose of this study was to identify the ideal sample size to represent the potential of a sugarcane family for identification of superior families, and, at the same time, determine which spatial arrangement may provide better phenotypic expression of the progeny of the sugarcane families tested. Thus, five full-sib families, each with 360 individuals, were evaluated in a randomized block design with three replications. The plants were placed in three different spatial arrangements in the row: 50 cm, 75 cm, and 100 cm between plants; with 150 cm between the rows. The bootstrap method was adopted to determine the ideal sample size, as well as the best spacing for evaluation. The 100-cm spacing provided the best mean values for number of stalks, mean stalk diameter, and estimated weight of stalks in the stool. The 75-cm spacing between plants within the row allowed better discrimi nation among the families for all the traits evaluated. At the 75-cm plant spacing, it was also possible to identify superior families with a sample of 30 plants from each plot and 3 reps in the trial.

MacLeish in Aiuruoca, Minas Gerais State, Brazil). Eremanthus erythropappus (DC.) MacLeish is a native species, economically appreciated due to its wood and the extraction of essential oil, whose active ingredient is alphabisabolol, but studies on genetic improvement of this species are still scarce. The aim of this study was to evaluate survival, genetic variability and estimate genetic parameters in E. erythropappus progenies in the field at 15, 22 and 30 months of age. The experiment was set up at Fazenda Guapiara, in Aiuruoca, Minas Gerais State, where seedlings of 15 progenies were planted in a randomized block design with five replications and six plants per plot. Plant height evaluations were performed and genetic studies were carried out in the SELEGEN software using the REML/BLUP method. At 30 months, the percentage of seedling survival was evaluated. Significant differences were observed between progenies, and the highest estimates of h²mp (0.48) and Acprog (0.69) were found at 30 months. Therefore, even in the juvenile stage, it was possible to identify genetic variability and analyze its expression over time, which makes it possible to continue studies of genetic improvement of the species.

MacLeish em Aiuruoca, MG, Brasil). Eremanthus erythropappus (DC.) MacLeish é uma espécie nativa, apreciada economicamente devido a sua madeira e à extração de óleo essencial, cujo princípio ativo é o alfabisabolol, porém os estudos em melhoramento genético dessa espécie ainda são escassos. Objetivou-se com este trabalho avaliar a sobrevivência e estimar parâmetros genéticos em progênies de E. erythropappus em campo aos 15, 22 e 30 meses de idade. O experimento foi instalado na Fazenda Guapiara, em Aiuruoca, MG, onde foram plantadas mudas de 15 progênies em delineamento de blocos casualizados, com cinco repetições e seis plantas por parcela. Foram realizadas avaliações da altura das plantas e procederam-se aos estudos genéticos no software SELEGEN por meio do método REML/BLUP. Aos 30 meses, foi avaliado o percentual de sobrevivência das mudas. Verificou-se diferenças significativas entre as progênies, e as maiores estimativas de h²mp (0,48) e de Acprog (0,69) foram encontradas aos 30 meses. Portanto, mesmo em estágio juvenil, foi possível identificar variabilidade genética e analisar a sua expressão ao longo do tempo, o que possibilita dar continuidade aos estudos visando o melhoramento genético da espécie.

Abstract Brazilian potato production is based on cultivars originating from the USA and Europe; however, these cultivars were developed under different environmental conditions than those found in Brazil. The aim of this study was to evaluate the adaptability and stability of 18 potato clones (MLG), developed by the Universidade Federal de Lavras, and four cultivars in six environments in the state of Minas Gerais, Brazil. The following traits were evaluated: marketable tuber yield (MTY), specific gravity (SG), and tuber appearance (TA). Clones, environments, and the genotype × environment interaction had significant effects on all traits. The GGE-biplot explained 71.78, 98.13, and 62.86 % of the sum of squares from the G+G×E for MTY, SG, and TA, respectively. Three MLG clones had higher adaptability and stability, as well as better performance, than the cultivars, making them good candidates for release as cultivars.

RESUMO (Caracterização genética no crescimento inicial de progênies de Eremanthus erythropappus (DC.) MacLeish em Aiuruoca, MG, Brasil). Eremanthus erythropappus (DC.) MacLeish é uma espécie nativa, apreciada economicamente devido a sua madeira e à extração de óleo essencial, cujo princípio ativo é o alfabisabolol, porém os estudos em melhoramento genético dessa espécie ainda são escassos. Objetivou-se com este trabalho avaliar a sobrevivência e estimar parâmetros genéticos em progênies de E. erythropappus em campo aos 15, 22 e 30 meses de idade. O experimento foi instalado na Fazenda Guapiara, em Aiuruoca, MG, onde foram plantadas mudas de 15 progênies em delineamento de blocos casualizados, com cinco repetições e seis plantas por parcela. Foram realizadas avaliações da altura das plantas e procederam-se aos estudos genéticos no software SELEGEN por meio do método REML/BLUP. Aos 30 meses, foi avaliado o percentual de sobrevivência das mudas. Verificou-se diferenças significativas entre as progênies, e as maiores estimativas de h2mp (0,48) e de Acprog (0,69) foram encontradas aos 30 meses. Portanto, mesmo em estágio juvenil, foi possível identificar variabilidade genética e analisar a sua expressão ao longo do tempo, o que possibilita dar continuidade aos estudos visando o melhoramento genético da espécie.

ABSTRACT Eremanthus erythropappus (DC.) MacLeish is a native species, economically appreciated due to its wood and the extraction of essential oil, whose active ingredient is alphabisabolol, but studies on genetic improvement of this species are still scarce. The aim of this study was to evaluate survival, genetic variability and estimate genetic parameters in E. erythropappus progenies in the field at 15, 22 and 30 months of age. The experiment was set up at Fazenda Guapiara, in Aiuruoca, Minas Gerais State, where seedlings of 15 progenies were planted in a randomized block design with five replications and six plants per plot. Plant height evaluations were performed and genetic studies were carried out in the SELEGEN software using the REML/BLUP method. At 30 months, the percentage of seedling survival was evaluated. Significant differences were observed between progenies, and the highest estimates of h2mp (0.48) and Acprog (0.69) were found at 30 months. Therefore, even in the juvenile stage, it was possible to identify genetic variability and analyze its expression over time, which makes it possible to continue studies of genetic improvement of the species.

Abstract Forage plant breeders often use visual scores to assess agronomic traits because of the costs associated with in-depth phenotyping in the initial stages of breeding cycles. The aim of this study was to investigate the impact of the number of graders on the effectiveness of indirect selection of high-yielding genotypes and determine an optimal number of graders in the early-stage trials of Urochloa ruziziensis. For that purpose, five graders assessed 2.219 U. ruziziensis genotypes in an augmented block design. Biomass production and vigor scores were evaluated in two cuts and were analyzed using a linear mixed model approach. Vigor scores were analyzed considering each grader's score and the combinations of two, three, four, and five graders. Genetic variance was significant for both traits. Visual evaluation was effective in identifying productive genotypes based on the statistical criteria. The optimal number of graders for indirect selection of high-yielding U. ruziziensis genotypes is three.

ABSTRACT Biomass sorghum is an alternative feedstock to cogenerate energy and produce second-generation ethanol. The aim of this study was to evaluate the Genotype by Environment Interaction (GEI) in biomass sorghum and to identify the hybrids that associate high adaptability and stability using the Toler nonlinear regression, the Genotypes plus Genotype by Environment (GGE) biplot, and the Annicchiarico recommendation index. Thirty-three experimental photoperiod-sensitive single-cross hybrids and three checks were evaluated in relation to the traits: flowering time, plant height, moisture content, green mass yield, and dry mass yield. It was observed that the effects of hybrids, environment, and GEI were expressive. The GEI was predominantly complex for the traits related to the biomass yield. The Toler, GGE biplot and Annicchiarico methods show complementarity. The experimental hybrids 1, 8, 22, 31 and 33 are promising because of associating stability and lower recommendation risk. The hybrids 1 and 8 present broad adaptability, while the hybrids 22, 31 and 33 exhibit specific adaptability to high quality environments.

ABSTRACT The non-structural carbon reserves in the various organs of trees are associated with their growth and the mechanism of resilience when exposed to environmental stresses, especially the water deficit. The goal of this study was to develop multivariate models to estimate the amount of non-structural carbohydrates (starch, sucrose, reducing sugars, total sugars and total non-structural carbohydrates) based on near infrared (NIR) spectra measured in solid wood and material reduced to powder. Partial least squares regression was used to associate the amount of non-structural carbohydrates (NSC) obtained by conventional laboratory analysis with NIR spectral signatures. The best predictive models were obtained from the wood reduced to powder. Validity for the NSC prediction in an external set of data presented the following statistics: reducing sugars with R²=0.90 and root mean square error (RMSE) of 2.54% dry matter, total sugars (R²=0.88, RMSE=2.76%), total NSC (R²=0.90, RMSE=2.58%), sucrose (R²=0.82, RMSE=0.06%) and starch (R²=0.80, RMSE=1.03%). The ability of models to estimate the NSC concentration in the growth rings and under divergent environmental conditions demonstrates the potential of the NIR tool to study the physiological responses of plants to different environmental stresses.

ABSTRACT. In most cases, in genetic breeding of Arabica coffee, plot size is defined in an empirical manner. It is often based only on the experience of the breeders and the availability of resources, potentially leading to a reduction in precision. Therefore, the aim of this study was to estimate the size of the experimental plot for evaluation of coffee yield. We evaluated two experiments for validation of cultivars with 12 treatments set up in a randomized complete block design with three replicates and plots composed of 50 plants. Each plant was considered as a basic unit. Estimates of ideal plot size were made by maximum curvature of the coefficient of variation, linear-plateau segmented model and by the resampling methods. We discussed the variations in the parameter estimates for different plot sizes. Divergence was seen among the plot sizes estimated by the different methodologies. Increasing the number of plants per plot led to a higher experimental precision to the point that the increase was no longer significant. The plot size recommended for evaluating coffee production is from seven to 19 plants.

Este trabalho foi realizado com objetivo de: i) comparar o índice de seleção somatório Z das variáveis padronizadas em relação ao clássico (SMITH, 1936; HAZEL, 1943) e soma de postos (MULAMBA e MOCK, 1978), por meio de caracteres de crescimento e tecnológicos da madeira e ii) verificar a interação progênies x ambientes na seleção simultânea de vários caracteres, com base no somatório Z das variáveis padronizadas. Para isto, foi utilizado um teste de progênies de irmãos completos de Eucalyptus urophylla e Eucalyptus grandis avaliado em dois ambientes no município de Ipaba - MG. Aos três anos de idade, foram avaliadas as seguintes características: incremento médio anual de madeira, densidade básica da madeira, rendimento depurado de celulose e álcali efetivo. Houve boa concordância na seleção de progênies pelos índices. Assim, o emprego do somatório Z das variáveis padronizadas é uma boa opção na seleção simultânea de vários caracteres no setor florestal, pela facilidade de aplicação e, sobretudo, de interpretação dos resultados. O referido índice se mostrou eficiente no estudo da interação genótipos x ambientes.

The aim of this study was i) to compare the results obtained with the Z index (sum of standardized variables) in relation to the classical (Smith, 1936; HAZEL, 1943) and rank sum indexes (Mulamba and MOCK, 1978) by means of the growth and wood technology traits and ii) to verify the progeny x environment interaction in simultaneous multiple trait selection, based on the Z index. Thus, we used a full sib progeny test of Eucalyptus urophylla and Eucalyptus grandis evaluated in two locations in the municipality of Ipaba, Minas Gerais state. At three years of age, the following traits were evaluated: average yearly increase of wood, wood density, refined pulp yield and effective alkali. There was good agreement in the progeny selection by the indexes. Thus, use of the Z index of standardized variables is a good option in simultaneous selection of multiple traits in the forestry sector through its ease of application and, above all, interpretation of results. The mentioned index revealed efficient in the study of the genotypes x environments interaction.

O objetivo deste trabalho foi avaliar a necessidade de bordadura e estimar o tamanho ótimo de parcela em experimentos para avaliação de Urochloa ruziziensis. Foram avaliadas a altura das plantas e a produção de massa verde de oito progênies de meio-irmãos de U. ruziziensis, em dois cortes. Utilizou-se o delineamento de blocos ao acaso, com quatro repetições e parcelas de 16 m². Cada parcela foi subdividida em 32 estratos de 0,5 m², sendo cada estrato considerado como uma unidade básica. Para determinar a necessidade de bordadura, foi realizada análise de variância, tendo-se considerado a posição da unidade básica na parcela. As estimativas do tamanho ótimo da parcela foram realizadas pelo método da máxima curvatura do coeficiente de variação e pelo método da reamostragem. O uso de bordaduras não altera o desempenho médio e a classificação das progênies de meio-irmãos avaliadas. O emprego de parcelas com 3 m² é suficiente para obter boa precisão experimental em experimento com progênies de meio-irmãos de U. ruziziensis.

The objective of this work was to assess the need for a border area and to estimate the optimum plot size in experiments for the evaluation of Urochloa ruziziensis. Plant height and green mass production of eight half-sib progenies of U. ruziziensis were evaluated in two cuttings. A randomized complete block design was used, with four replicates and 16 m² plots. Each plot was subdivided into 32 strata of 0.5 m², with each stratum being considered as a basic unit. To determine the need for a border area, analysis of variance was carried out considering the position of the basic unit in the plot. Estimates of optimum plot size were made by the maximum curvature of the coefficient of variation method and by the resampling method. The use of borders does not affect the mean performance and classification of the half-sib progenies evaluated. The use of 3 m² plots is enough to obtain good experimental accuracy in an experiment with half-sib progenies of U. ruziziensis.

RESUMO O presente trabalho foi realizado com o objetivo de comparar estratégias de análises de experimentos considerando um grande número de clones e um número reduzido de mudas a serem avaliadas. Foram analisados dados da circunferência a altura do peito de duas épocas de avaliação, aos 30 e 90 meses, de um teste clonal de eucalipto em três locais. Os experimentos foram conduzidos no delineamento de blocos aumentados, com 400 clones regulares distribuídos em 20 blocos e com quatro clones comuns (testemunhas). A parcela foi constituída de cinco plantas no espaçamento 3 x 3 metros. Foram realizadas as análises estatísticas individuais por local e época, a conjunta de locais por época e a conjunta envolvendo os três locais e as duas épocas. Cada uma das análises foi realizada de acordo com dois modelos: blocos aumentados (DBA) e entre e dentro (ED). Foram estimados os componentes de variância, as herdabilidades, a correlação de Spearman na classificação dos clones e os índices de coincidência na seleção dos clones. Constatou-se que as análises em DBA e as análises ED fornecem resultados semelhantes na avaliação de clones de eucalipto. Os índices de coincidência entre os dois modelos na seleção dos clones, de maneira geral, foram altos, apresentando valores de 100% nas análises conjuntas de locais aos 90 meses. As estimativas das correlações de Spearman foram concordantes com os índices de coincidência. Verificou-se, também, que a interação clones x épocas foi expressiva e que os índices de coincidência na seleção dos clones aos 30 meses e aos 90 meses, nas análises conjuntas de locais, foram da ordem de 42% no ED e 47% no DBA, quando considerada uma intensidade de seleção de 5%.

ABSTRACT The objective of this work was to compare analyses of experiment strategies when there is a large number of clones and a reduced number of seedlings to be evaluated. Data from girth at breast height of two seasons of evaluation, 30 and 90 months, from a clonal test of Eucalyptus were analyzed in three locations. The experiments were carried out in the augmented block design with 400 regular clones distributed in 20 blocks and with four common clones (controls). Each plot consisted of five plants spaced 3 x 3 meters. The individual statistic analyses were carried out by season and local, a combined one by local at each season and a combined one involving the three locals and the two seasons. Each analysis was carried out according to two models: augmented design (AD) and one-way classification (OWC). The variance components, the heritability, the Speaman's rank correlation and the coincidence indexes in the clone selection at the two models were estimated. It was found that the augmented block design and the one-way classification provide similar results in eucalypt clone evaluation. The coincidence indexes between the two models in the clone selection, in general, were high, showing values of 100% in the local combined analyses at 90 months. The Spearman's rank correlation showed estimates in accordance with the coincidence indexes. It was also checked that the clones by seasons interaction was expressive and the coincidence indexes in clones selection at 30 months with selection at 90 months in the combined by local analyses were from 42% in the OWC and 47% in AD, when a selection intensity of 5% was applied.

Este trabalho teve por objetivo avaliar a adaptabilidade e estabilidade fenotípica da produtividade de genótipos do grupo Mundo Novo pelos métodos TOLER e AMMI de maneira a compará-los e a selecionar aqueles que apresentassem alta adaptabilidade produtiva nas regiões produtoras de café do estado de Minas Gerais. Foram instalados e conduzidos experimentos em Três Pontas, Campos Altos e Capelinha, em delineamento de blocos casualizados, com quatro repetições e seis plantas por parcela. Os tratamentos foram constituídos por 33 genótipos do grupo Mundo Novo obtidos no Programa de Melhoramento Genético do Cafeeiro conduzido pelo Instituto Agronômico de Campinas (IAC). As avaliações de produção foram efetuadas ao longo de seis colheitas, as quais foram agrupadas em biênios. Cada combinação biênio x local foi considerada um ambiente, totalizando nove ambientes de estudo. Uma vez detectada a presença de interação genótipo x ambiente pelo teste de F de Snedecor, procedeu-se à análise de estabilidade, sendo a adaptação representada pela produtividade. Os métodos AMMI e TOLER foram semelhantes ao classificar os genótipos e ambientes e devem ser usados em conjunto em programas de melhoramento do cafeeiro para maior confiabilidade das informações, uma vez que suas interpretações são complementares. A estabilidade foi associada, nesse estudo, com baixa adaptabilidade. Os genótipos IAC 379-19, IAC 388-6-16 e IAC 403-1 apresentaram-se instáveis com alta adaptabilidade. Os genótipos IAC 2931 e IAC 480 se enquadram como desejáveis, pois associam estabilidade média e produtividade considerável.

The purpose of this study was to evaluate the phenotypic adaptability and stability for yield in coffee genotypes of the cultivar "Mundo Novo" by using the methods TOLER and AMMI, as well as to select genotypes with high productive adaptability in the coffee growing regions of Minas Gerais. The experiments were carried out in Três Pontas, Campos Altos and Capelinha, Minas Gerais, Brazil, in a randomized complete block design with four repetitions and six plants per plot. The treatments consisted of 33 genotypes of cultivar "Mundo Novo" provided by the coffee plant breeding program of the Instituto Agronômico (IAC). The yield analyses were performed during six harvests, which were grouped in bienniums. Each combination biennium x site was considered an environment totalizing nine environments. Once the genotype x environment interaction was detected by the F test of Snedecor, the stability analysis was done with the adaptation being represented by yield. The methods AMMI and TOLER were similar when classifying the genotypes and environments, and should be used together in coffee breeding programs in order to obtain greater reliability of information, as they are complementary. In this study the stability was associated with low adaptability. The IAC 379-19, IAC 388-6-16 and IAC 403-1 genotypes were unstable with high adaptability. The IAC 2931 and IAC 480 genotypes were classified as desirable due to average stability associated with reasonable yield.

O conhecimento das correlações genéticas entre os principais caracteres utilizados no melhoramento de plantas serve de base para delinear estratégias otimizadas de seleção. O procedimento da análise de trilha permite refinar essas correlações, desdobrando-as em efeitos diretos e indiretos sobre o caráter principal. O objetivo deste trabalho foi desdobrar as correlações genéticas de caracteres relativos ao cacho e à produção de frutos em progênies de meios-irmãos de açaizeiro em efeitos diretos e indiretos sobre a produção total de frutos, a fim de verificar a melhor estratégia de seleção para obtenção de progênies mais produtivas. Foi instalado um experimento com 25 progênies de meios-irmãos em blocos ao acaso, com quatro repetições e parcela de cinco plantas. Os dados dos anos agrícolas de 2005, 2006 e 2007 foram analisados pelo enfoque de modelos mistos, e as correlações genéticas, submetidas à análise de trilha. A produção de frutos correlacionou-se ao número de meses em produção, número total de cacho, peso de frutos por cacho e ao número de ráquilas por cacho. No entanto, pela análise de trilha, apenas o peso de frutos por cacho, o número de cachos e o número de ráquilas por cacho mostram-se como os principais determinantes na variação da produção de frutos de açaizeiro. Dentre esses caracteres, o número de ráquilas por cacho é o menos influenciado pelo ambiente e, portanto, mais promissor para obter ganhos indiretos na produção total de frutos.

The knowledge of the genetics correlations among the main characters used in plant breeding helps to elaborate optimized strategies of selection. The procedure of path analysis allows refining these correlations and partitioning them into direct and indirect effects on a main variable. The objective of this study was to partition the genetic correlations of traits concerning to bunch and yield of half-sib progenies into direct and indirect effects on total fruit production. It was installed an experiment with 25 half-sib progenies in random blocks with four repetitions and linear plots of five plants. The data obtained over the crop years 2005, 2006 and 2007 was analyzed by mixed models approach and genetics correlations submitted to path analysis. The fruits production showed correlation with number of months in production, total number of bunch, fruit weight per bunch and number of rachilles per bunch. However, by path analysis, the main determinants characters of variation on fruit production of assai palm were fruits weight per bunch, number of bunches and number of rachilles per bunch. Among these characters, the number of rachilles per bunch is less affected by the environment, and therefore, is the most promising for indirect gains in total fruit production.