Genetic parameters, genetic trends and correlated responses of growth traits considering maternal ability in Nelore cattle.

The growth of Nelore cattle was analysed considering the following performance parameters; the effect of the calving order of cows on the phenotypic expression of birth weight (BW), average daily gain from birth to weaning (BWG), and weaning weight (WW), the estimated genetic parameters for the traits, including the covariance components between direct and maternal genetic effects. Genetic trends and correlated responses were also obtained for the studied traits. The calving order of cows, as well as other fixed effects used to obtain the adjusted phenotypic means, were statistically significant (p < 0.001) for studied traits. Direct heritability was estimated at 0.24 ± 0.01 (BW), 0.15 ± 0.01 (BWG), and 0.18 ± 0.01 (WW), while maternal heritability was 0.06 ± 0.01 (BW), 0.12 ± 0.01 (BWG), and 0.11 ± 0.01 (WW). The correlations between direct and maternal effects within the same trait were negligible. Moderate to higher direct genetic correlations (ranging from 0.54 ± 0.04 to 0.98 ± 0.01) and maternal genetic correlations (ranging from 0.34 ± 0.09 to 0.99 ± 0.002) were estimated between the studied traits. Unlike direct genetic effects, there was no significant change in maternal genetic effects over time (p > 0.05). These results indicated the need for revising selection indexes for enhancing maternal ability. Correlated responses were generally lower compared to direct responses, except for BWG. The selection for BWG, considering the maternal genetic effect, would be more efficient to improve maternal ability of the cows for pre-weaning growth in relation to selection for WW. Our results found that direct genetic merit improves pre-weaning weight and this trait can be incorporated into the breeding goal as reflected in the WW.

Canonical correlations between high and low heritability wheat traits via mixed models / Correlações canônicas entre caracteres de trigo de alta e baixa herdabilidade via modelos mistos

ABSTRACT: Canonical correlation analysis based on genotypic correlations allows determining the associations between groups of traits and carrying out the direct or indirect selection of superior genotypes. This study investigated the existence of linear and multivariate relationships between high and low heritability traits via canonical correlation analysis based on genotypic correlations. The experiment was conducted at the Professor Diogo Alves de Melo Experimental Field at the Universidade Federal de Viçosa, in Viçosa, MG. 90 wheat cultivars were evaluated under a 9 × 10 alpha-lattice design, with three replications and plots consisting of four rows of three meters spaced at 0.20 meters. Canonical groups were established between spike height and plant height, days for heading, number of spikelets per spike, and number of grains per spike (Group I) and, spike weight, spike grain mass, 100-grain mass, hectoliter weight, and grain yield (Group II). There was dependence between the established groups, which allowed the investigation of the relationships between traits based on their genotypic values. The traits cycle and plant height can be used for indirect selection of genotypes superior in hectoliter weight and grain yield, which are important factors for industries and farmers.

RESUMO: As análises de correlações canônicas baseadas nas correlações genotípicas, permitem determinar associações entre grupos de caracteres e realizar a seleção direta ou indireta de genótipos superiores. Objetivou-se com este trabalho investigar a existência de relações lineares e multivariadas entre caracteres de alta e baixa herdabilidade via análise de correlações canônicas com base nas correlações genotípicas. O experimento foi conduzido no Campo Experimental Professor Diogo Alves de Melo da Universidade Federal de Viçosa, em Viçosa, Minas Gerais. 90 cultivares de trigo foram avaliadas sob o delineamento alpha-lattice 9 × 10, com três repetições e parcelas constituídas por quatro linhas de três metros espaçadas a 0.20 metros. Os grupos canônicos foram estabelecidos entre altura de espiga e planta, dias para o espigamento, número de espiguetas por espiga e número de grãos por espiga (Grupo I) e, peso de espiga, massa de grãos da espiga, massa de 100 grãos, peso hectolitro e produtividade de grãos (Grupo II). Houve dependência entre os grupos estabelecidos, o que permitiu a investigação das relações entre os caracteres com base em seus valores genotípicos. Os caracteres ciclo e altura de plantas podem ser utilizados para a seleção indireta de genótipos superiores em peso hectolitro e produtividade, fatores estes importantes para indústrias e produtores.

Canonical correlations between high and low heritability wheat traits via mixed models / Correlações canônicas entre caracteres de trigo de alta e baixa herdabilidade via modelos mistos

Canonical correlation analysis based on genotypic correlations allows determining the associations between groups of traits and carrying out the direct or indirect selection of superior genotypes. This study investigated the existence of linear and multivariate relationships between high and low heritability traits via canonical correlation analysis based on genotypic correlations. The experiment was conducted at the Professor Diogo Alves de Melo Experimental Field at the Universidade Federal de Viçosa, in Viçosa, MG. 90 wheat cultivars were evaluated under a 9 × 10 alpha-lattice design, with three replications and plots consisting of four rows of three meters spaced at 0.20 meters. Canonical groups were established between spike height and plant height, days for heading, number of spikelets per spike, and number of grains per spike (Group I) and, spike weight, spike grain mass, 100-grain mass, hectoliter weight, and grain yield (Group II). There was dependence between the established groups, which allowed the investigation of the relationships between traits based on their genotypic values. The traits cycle and plant height can be used for indirect selection of genotypes superior in hectoliter weight and grain yield, which are important factors for industries and farmers.

As análises de correlações canônicas baseadas nas correlações genotípicas, permitem determinar associações entre grupos de caracteres e realizar a seleção direta ou indireta de genótipos superiores. Objetivou-se com este trabalho investigar a existência de relações lineares e multivariadas entre caracteres de alta e baixa herdabilidade via análise de correlações canônicas com base nas correlações genotípicas. O experimento foi conduzido no Campo Experimental Professor Diogo Alves de Melo da Universidade Federal de Viçosa, em Viçosa, Minas Gerais. 90 cultivares de trigo foram avaliadas sob o delineamento alpha-lattice 9 × 10, com três repetições e parcelas constituídas por quatro linhas de três metros espaçadas a 0.20 metros. Os grupos canônicos foram estabelecidos entre altura de espiga e planta, dias para o espigamento, número de espiguetas por espiga e número de grãos por espiga (Grupo I) e, peso de espiga, massa de grãos da espiga, massa de 100 grãos, peso hectolitro e produtividade de grãos (Grupo II). Houve dependência entre os grupos estabelecidos, o que permitiu a investigação das relações entre os caracteres com base em seus valores genotípicos. Os caracteres ciclo e altura de plantas podem ser utilizados para a seleção indireta de genótipos superiores em peso hectolitro e produtividade, fatores estes importantes para indústrias e produtores.

Selection strategies for identifying fast cooking, mineral-biofortified bean cultivars with high agronomic performance

Simultaneous selection for various agronomic traits, cooking time and mineral concentration are major challenges for common-bean (Phaseolus vulgaris L.) breeding programs. The authors of this study proposed to analyze genetic gain estimates obtained by direct and indirect selection using selection indices and economic weights for 13 traits, and to determine the most efficient selection strategy for the simultaneous selection of fast cooking, mineral-biofortified common bean cultivars with high agronomic performance. For this purpose, three experiments were carried out in different growing seasons to evaluate 49 common bean cultivars of different grain types. Agronomic performance was evaluated based on six traits; cooking time was determined using a Mattson cooker; and the concentration of six minerals was analyzed in samples of raw grains. Significant genotype × environment interaction or genotype effects were observed for all traits, indicating the existence of genetic variability. Direct selection resulted in high genetic gain estimates for individual traits, but caused undesirable changes in one or more of the traits under selection. The classic, base, desired-gains and rank-sum selection indices tested with six economic weights do not provide genetic gain estimates favorable to the selection of all traits. The multiplicative index is the best selection strategy for use in the breeding program when aiming at the simultaneous selection of fast cooking, mineral-biofortified common bean cultivars with high agronomic performance.

Correlations and path analysis in agronomic traits of soybeans under defoliation / Correlações e análise de trilha em caracteres agronômicas de soja sob desfolha

Stress events or leaf damage can alter the redistribution of photoassimilates and modify the morphological traits directly related to grain yield. This study aimed to evaluate the influence of agronomic traits on grain yield in soybean crop in function of leaf defoliation. The experiment consisted of a randomized block design with three replications, arranged in a 6 x 3 + 1 factorial scheme. The factors were composed by six reprodutive stages (R1, R2, R3, R4, R5, and R6) and three defoliation levels (33%, 66%, and 99%), and one additional treatment without defoliation (control). The following traits were evaluated: plant height, number of pods per plant, number of grains per pod, thousand grain weight, and grain yield. The magnitudes of the correlations between the same traits showed high oscillation according to the defoliation level. Results revealed the potential for the indirect selection for grain yield by the traits plant height and number of grains per pods under 0% of defoliation and by the trait number of pods per plant under 33% of defoliation.

Ocorrências de estresse ou danos foliares podem levar a alteração na redistribuição de fotoassimilados e modificar os caracteres morfológicos envolvidos diretamente na produtividade dos grãos. Portanto, objetivou-se avaliar por meio da análise de trilha, a influência de caracteres agronômicos na produtividade de grãos na cultura da soja em função de níveis desfolha da planta. O delineamento experimental utilizado foi o de blocos casualizados com três repetições, dispostos em esquema fatorial 6 x 3 + 1. O primeiro fator foi composto por seis estádios reprodutivos de desfolha (R1, R2, R3, R4, R5, R6) x três níveis de desfolha (33%, 66%, 99%) e um tratamento adicional sem desfolha (controle). Os caracteres avaliados foram: altura de plantas, número de legumes por planta, número de grãos por legume, peso de mil grãos e produtividade de grãos. As magnitudes das correlações entre os mesmos caracteres apresentaram alta oscilação de acordo com o nível de desfolha, sendo que, que existe potencial da seleção indireta para produtividade de grãos por meio da altura de plantas e número de grãos por legumes sob 0% desfolha e do número de legumes por planta sob 33% de desfolha.

Estimated genetic associations among reproductive traits in Nellore cattle using Bayesian analysis.

Scrotal circumference of bulls is correlated with pubertal age of female offspring. Hormonal control of reproductive function is similar in males and females, which may result in genetic correlation among different reproductive traits measured in the two sexes. The estimation of heritability and genetic correlations allows for the computation of direct and correlated genetic gains which are important for predicting of outcomes as a result of genetic-based selection. The aim of this study was to estimate genetic parameters and relative efficiency of indirect selection for age at first calving (AFC), stayability (STAY) and scrotal circumference at 365 days of age (SC365) in Nellore cattle. The STAY variable can be defined as the probability of a cow remain in the herd enough time to raise a certain number of calves that pay for her development and maintenance costs. A bivariate Bayesian analysis was used to estimate variance components using a linear-animal model for SC365 and AFC and threshold-linear model for SC365 and STAY and for AFC and STAY. For STAY, the value of 1 was assigned to cows that calved at least three times by 76 months of age; otherwise, the value 0 was assigned. The posteriori means of heritability estimates were 0.29, 0.08 and 0.09 for SC365, AFC and STAY, respectively. Genetic correlations were favorable from a cow productivity perspective between SC365 and AFC, and SC365 and STAY (-0.45 and 0.12, respectively). Indirect selection approaches were more efficient than direct selection for AFC (ERS = 1.87) when animals were selected for SC365.

Selection tools for oil content and fatty acid composition in safflower (Carthamus tinctorius L.).

Agricultural expansion requires the deployment of stress-tolerant crops like safflower (Carthamus tinctorius L.). In safflower breeding, oil improvement in early generations requires indirect selection through simply inherited traits. The oil quality is mostly related to the fatty acid profile, which is determined by the OL locus. The aim of this research was to identify simple easy-to-measure traits that indirectly explain oil content variation and its interaction with yield components, and also to generate an effective tool for genotyping the OL locus. A field experiment with F5 and pure lines was carried out to correlate the oil content with 18 traits including yield components, and phenological and morphological characteristics. KASP technology using primers designed according to the ctFAD2-1 gene sequence was applied for OL locus genotyping and validated through fatty acids phenotyping. Hull content, the length:width ratio of the grain, and plant height were identified as the most promising selection tools for increasing oil content, and grains per capitulum was the best yield component for increasing yield without decreasing the oil content. KASP genotyping successfully worked as a MAS tool, identifying oleic and linoleic genotypes. These tools enhance options for improving oil content and quality for safflower breeding.

Selection of lineages, genetic parameters, and correlations between soybean characters / Seleção de linhagens, parâmetros genéticos e correlações entre caracteres em soja

Soybean has great economic importance in the world accordingly, this legume has been exploited in breeding programs aiming to provide cultivars with extensive grain yield, tolerant to pests and diseases, and adapted to different soil and climatic conditions. Therefore, the objectives of this study were to evaluate genetic parameters and correlations between soybean traits to select lineages to increase yield and improve agronomic traits. Experiments were carried out on the Capim Branco farm, of the Federal University of Uberlândia, harvest in 2016/2017. Fifteen morph-agronomic traits were assessed on twenty-two genotypes in a randomized complete block design with three replicates. Agronomic traits related to cycle, height, number of nodes and total pods have shown coefficients of genotypic determination higher than 70%. In addition, coefficients of variation of the number of days to the flowering and number of days to maturity were equal to 3.79% and 4.87%, respectively, indicating high homogeneity of data and low random variation. Among evaluated traits, ten have presented the ratios between the coefficient of genetic variation (CVg) and coefficient of environmental variation (CVe) above one, demonstrating high success likelihood in the selection of these traits. Fifteen genotypes have presented grain yield above the national average of the 2016/2017 harvest, which was 2882 kg h-1. Significant phenotypic correlations between traits ranged from -0.49 to 0.89, however genotype correlation was higher than the phenotypic ones, indicating that genetic factors have contributed more than the environmental factors. Traits related to cycle, height, and the number of nodes in the main stem have presented measures of H² and CVg / CVe with extensive magnitudes, evidencing the possibility of selection lineages having superior traits in the Soybean Breeding Program of the Federal University of Uberlândia. To increasing grain yield, the traits Number of pods of three grains and the Total number of pods were identified as appropriated to indirect selection based on the phenotypic and genotypic correlations. The 2lP14, B2P1, B2P28, B1P33 and 2AP11 lineages stand out as superior genotypes to direct selection.

A soja é uma cultivar de grande importância econômica mundial e por esse motivo essa leguminosa é explorada nos programas de melhoramento, que visam disponibilizar cultivares de alta produtividade de grãos, tolerantes a pragas e doenças e adaptadas à diferentes condições edafoclimáticas. Os objetivos desse trabalho foram selecionar linhagens, avaliar parâmetros genéticos e correlações entre caracteres de soja. O experimento foi conduzido na área experimental da Fazenda Capim Branco pertencente à Universidade Federal de Uberlândia na safra de 2016/2017. Avaliaram-se 22 genótipos em delineamento deblocos completos casualizados com três repetições para 15 caracteres morfo-agronômicos. Os caracteres agronômicos relacionados ao ciclo, altura, número de nós e vagens totais tiveram coeficiente de determinação genotípico superiores a 70%. Obteve-se coeficiente de variação para o caráter número de dias para o florescimento igual a 3,79% e para o caráter número de dias para maturação, 4,87%, indicando maior homogeneidade entre os dados e baixa variação ao acaso. Dos caracteres avaliados, dez apresentaram razão entre coeficiente de variação genético e coeficiente de variação ambiental superiores a um, demonstrando oportunidade de sucesso no processo de seleção para esses respectivos caracteres. 15 genótipos obtiveram produtividade de grãos superior à média nacional de safra 2016/2017, isto é, a 2882 kg h-1. As correlações fenotípicas entre caracteres que foram significativas oscilaram de -0,49 a 0,89, cujas estimativas de correlação genotípica foram superiores à correlação fenotípica, indicando que os fatores genéticos contribuíram mais que os ambientais. Os caracteres relacionados ao ciclo, altura e número de nós na haste principal, tiveram H² de elevada magnitude e altas estimativas na razão CVg/CVe, evidenciando a possibilidade de seleção de linhagens superiores no Programa de Melhoramento de Soja da Universidade Federal de Uberlândia. Considerando o caráter produtividade de grãos, foi possível identificar número de vagens de três grãos e número total de vagens para a seleção indireta, com base nas correlações fenotípicas e genotípicas. As linhagens 2lP14, B2P1, B2P28, B1P33 e 2AP11 destacam-se como genótipos superiores na seleção direta.

Inferences on the effects of selection for feed conversion over meat quality traits in broiler

The intense selection process for economic traits conducted by the poultry breeding programs has been caused several changes in broiler meat quality. A database belonging to a selection program of a broiler male line was used to estimate heritability and genetic correlations for feed conversion ratio and meat quality traits, which were: initial and final pH, lightness, drip loss, thawing loss and shear force. Two-trait analyses were performed and the components of co(variance) and genetic parameters were determined using the Bayesian approach and the GIBBS3F90 software. The heritability estimate found for feed conversion ratio (0.52) showed high influence of direct additive genetic effects on the expression of this trait; therefore, this trait is able to respond to selection. The genetic correlation estimates obtained (-0.50 to 0.33) were indicative of important associations between feed conversion ratio and meat quality traits. The selection to improve feed conversion ratio may cause injury in greater or lesser degree for L*, drip loss (DL), thawing loss (TL) and shear force (SF) in broilers. It is recommended the monitoring of consequences of feed conversion ratio used as selection criteria or meat quality traits in broilers, due to its unfavorable indirect selection for these variables in this population. Breeding methods for efficiency improvements in broilers feed are suggested, which also benefit sensorial and functional properties of the meat.

Inferences on the effects of selection for feed conversion over meat quality traits in broiler

The intense selection process for economic traits conducted by the poultry breeding programs has been caused several changes in broiler meat quality. A database belonging to a selection program of a broiler male line was used to estimate heritability and genetic correlations for feed conversion ratio and meat quality traits, which were: initial and final pH, lightness, drip loss, thawing loss and shear force. Two-trait analyses were performed and the components of co(variance) and genetic parameters were determined using the Bayesian approach and the GIBBS3F90 software. The heritability estimate found for feed conversion ratio (0.52) showed high influence of direct additive genetic effects on the expression of this trait; therefore, this trait is able to respond to selection. The genetic correlation estimates obtained (-0.50 to 0.33) were indicative of important associations between feed conversion ratio and meat quality traits. The selection to improve feed conversion ratio may cause injury in greater or lesser degree for L*, drip loss (DL), thawing loss (TL) and shear force (SF) in broilers. It is recommended the monitoring of consequences of feed conversion ratio used as selection criteria or meat quality traits in broilers, due to its unfavorable indirect selection for these variables in this population. Breeding methods for efficiency improvements in broilers feed are suggested, which also benefit sensorial and functional properties of the meat.(AU)

Path analysis for selection of feijoa with greater pulp weight / Análise de trilha para seleção de goiabeira-serrana com maior peso de polpa

The objective of this paper was to identify the direct and indirect effects of feijoa fruits (Acca sellowiana) traitson pulp weight, in order to use these traits in indirect genotypes selection. Fruits of five feijoa plants were collected in Rio Grande do Sul, in the years of 2009, 2010 and 2011. Six traits were evaluated: diameter, length, total weight, pulp weight, peel thickness and number of seeds per fruit. In the path analysis, with or without ridge regression, pulp weight was considered as the basic variable, and the other traits were considered as explanatory variables. Total weight and fruit diameter had high direct effect, and are the main traits associated with pulp weight. These traits may serve as criteria for indirect selection to increase feijoa pulp weight, since they are easy to be measured.

O objetivo deste trabalho foi identificar os efeitos diretos e indiretos de caracteres dos frutos de goiabeira-serrana (Accasellowiana) sobre o peso de polpa, visando à utilização desses caracteres para a seleção indireta de genótipos. Foram coletados frutos de cinco grupo de plantas de goiabeira-serrana no Rio Grande do Sul, nos anos de 2009, 2010 e 2011. Seis caracteres foram avaliados: diâmetro, comprimento, peso total, peso de polpa, espessura da casca e número de sementes por fruto. Na análise de trilha com e sem regressão em crista para controle da multicolinearidade, o peso de polpa foi considerado variável básica e os demais caracteres considerados explicativos. O peso total, seguido do diâmetro de fruto, tiveram efeito direto elevado e são os principais caracteres associados ao peso de polpa. Estes caracteres podem servir de critérios de seleção indireta para aumentar o peso de polpa de goiabeira-serrana, pois são de fácil mensuração.

Path analysis for selection of feijoa with greater pulp weight / Análise de trilha para seleção de goiabeira-serrana com maior peso de polpa

The objective of this paper was to identify the direct and indirect effects of feijoa fruits (Acca sellowiana) traitson pulp weight, in order to use these traits in indirect genotypes selection. Fruits of five feijoa plants were collected in Rio Grande do Sul, in the years of 2009, 2010 and 2011. Six traits were evaluated: diameter, length, total weight, pulp weight, peel thickness and number of seeds per fruit. In the path analysis, with or without ridge regression, pulp weight was considered as the basic variable, and the other traits were considered as explanatory variables. Total weight and fruit diameter had high direct effect, and are the main traits associated with pulp weight. These traits may serve as criteria for indirect selection to increase feijoa pulp weight, since they are easy to be measured.(AU)

O objetivo deste trabalho foi identificar os efeitos diretos e indiretos de caracteres dos frutos de goiabeira-serrana (Accasellowiana) sobre o peso de polpa, visando à utilização desses caracteres para a seleção indireta de genótipos. Foram coletados frutos de cinco grupo de plantas de goiabeira-serrana no Rio Grande do Sul, nos anos de 2009, 2010 e 2011. Seis caracteres foram avaliados: diâmetro, comprimento, peso total, peso de polpa, espessura da casca e número de sementes por fruto. Na análise de trilha com e sem regressão em crista para controle da multicolinearidade, o peso de polpa foi considerado variável básica e os demais caracteres considerados explicativos. O peso total, seguido do diâmetro de fruto, tiveram efeito direto elevado e são os principais caracteres associados ao peso de polpa. Estes caracteres podem servir de critérios de seleção indireta para aumentar o peso de polpa de goiabeira-serrana, pois são de fácil mensuração.(AU)

Path analysis for selection of feijoa with greater pulp weight / Análise de trilha para seleção de goiabeira-serrana com maior peso de polpa

ABSTRACT: The objective of this paper was to identify the direct and indirect effects of feijoa fruits (Acca sellowiana) traitson pulp weight, in order to use these traits in indirect genotypes selection. Fruits of five feijoa plants were collected in Rio Grande do Sul, in the years of 2009, 2010 and 2011. Six traits were evaluated: diameter, length, total weight, pulp weight, peel thickness and number of seeds per fruit. In the path analysis, with or without ridge regression, pulp weight was considered as the basic variable, and the other traits were considered as explanatory variables. Total weight and fruit diameter had high direct effect, and are the main traits associated with pulp weight. These traits may serve as criteria for indirect selection to increase feijoa pulp weight, since they are easy to be measured.

RESUMO: O objetivo deste trabalho foi identificar os efeitos diretos e indiretos de caracteres dos frutos de goiabeira-serrana (Accasellowiana) sobre o peso de polpa, visando à utilização desses caracteres para a seleção indireta de genótipos. Foram coletados frutos de cinco grupo de plantas de goiabeira-serrana no Rio Grande do Sul, nos anos de 2009, 2010 e 2011. Seis caracteres foram avaliados: diâmetro, comprimento, peso total, peso de polpa, espessura da casca e número de sementes por fruto. Na análise de trilha com e sem regressão em crista para controle da multicolinearidade, o peso de polpa foi considerado variável básica e os demais caracteres considerados explicativos. O peso total, seguido do diâmetro de fruto, tiveram efeito direto elevado e são os principais caracteres associados ao peso de polpa. Estes caracteres podem servir de critérios de seleção indireta para aumentar o peso de polpa de goiabeira-serrana, pois são de fácil mensuração.

Correlation between yield components in F6 soybean progenies derived from seven biparental crosses / Correlação entre caracteres em progênies F6 de soja provenientes de sete cruzamentos biparentais

Breeding programs strive to obtain cultivars with superior traits. The association between these characters, such as those estimated by correlation coeficients, are important to the breeding selection process. In this study we analyzed phenotypic and genotypic correlations between yield and other agronomic traits in soybean progenies derived from various crosses to support breeding line selection in the soybean breading program of the Federal University of Uberlandia (UFU). The experiment was carried out in the 2011/2012 growing season at the Capim Branco research station in Uberlandia, Minas Gerais, Brazil. Seventy-one soybean lines were evaluated using a randomized complete block design with three replications. In these plots plants were evaluated for the number of pods, grain yield per plant, number of days for flowering, plant height at flowering, number of days for maturity, plant height at maturity, height of the first pod insertion, number of grains per pod and grain yield per plant. The estimates for genotypic correlations were equal or greater than those for the phenotypic correlations for all the evaluated traits. This suggests a small effect of environmental factors on the trait expression. An exception of this behavior was the correlation between plant height at flowering and plant height at maturity. In this case, although the signs for the genotypic and phenotypic correlations were the same, the value for the last was greater than that for the former. The late flowering and late-maturing plants were taller. Also, selecting plants for higher number of pods ultimately contributed for the selection of plants with higher grain yield. The selection of late-flowering and late-maturing plants have yielded taller plantsin the same way that the selection for a higher pod number could promote the selection and improvement of grains yield trait.

O objetivo dos programas de melhoramento genético de qualquer cultura é a obtenção de cultivares que superem com vantagens as pré-existentes. Desse modo, o conhecimento das relações entre caracteres, tais como estimadas pelas correlações, tem apresentado grande importância para o sucesso dos processos de seleção no melhoramento. Os objetivos deste estudo foram avaliar as correlações fenotípicas e genotípicas entre caracteres agronômicos de linhagens de soja oriundas de diferentes cruzamentos, visando fornecer subsídios para fins de seleção a ser adotado no programa de melhoramento genético de soja da Universidade Federal de Uberlândia. O experimento foi conduzido em uma área experimental localizada na Fazenda Capim Branco, pertencente à Universidade Federal de Uberlândia, no município de Uberlândia, Minas Gerais, na safra 2011/2012. Foram avaliados 71 linhagens de soja em delineamento de blocos completos casualisados com três repetições. Avaliaram-se os caracteres: número total de vagens, produção de grãos por planta, número de dias para o florescimento, altura da planta no florescimento, número de dias para maturidade, altura da planta na maturidade, altura de inserção de primeira vagem, número de grãos por vagem e produção de grãos por planta. Para todos os caracteres, com exceção da correlação entre altura da planta no florescimento e maturidade em que a apesar de apresentarem mesma direção, a magnitude da correlação fenotípica superou a correlação genotípica, as correlações genotípicas foram superiores as fenotípicas e de igual sinal, indicando menor influência do ambiente na expressão dos caracteres. A seleção de plantas mais tardias no florescimento e maturidade, resulta em plantas mais altas nesses estádios de desenvolvimento, bem como a seleção de plantas com maior número de vagens favorece a seleção e melhoramento para o caractere produção de grãos por planta.

Relações lineares entre caracteres de aveia preta / Linear relations among characters of black oat

É importante estudar as relações lineares entre os caracteres para a seleção indireta de plantas. O objetivo deste trabalho foi avaliar as relações lineares entre caracteres de aveia preta (Avena strigosa Schreb) e identificar caracteres para a seleção indireta. Foi conduzido experimento a campo e, em dez épocas de avaliação (22, 28, 34, 42, 48, 55, 76, 83, 90 e 105 dias após a semeadura), foram selecionadas, aleatoriamente, 52 plantas, totalizando 520 plantas. Em cada planta, foram mensurados os caracteres altura de planta, números de folhas e de perfilhos e as massas verde e seca. Foi ajustado o modelo sigmoidal e investigada a relação entre os caracteres por meio de análises de correlação e de trilha. Na cultura de aveia preta, o número de folhas por planta e a altura de planta têm relação linear positiva com as massas verde e seca e podem ser utilizados para seleção indireta.

It is important to study the linear relations among characters for indirect selection of plants. The objective of this paper was to evaluate the linear relations among characters of black oat (Avena strigosa Schreb) and identify characters for indirect selection. Field experiment was conducted and in ten evaluation times (22, 28, 34, 42, 48, 55, 76, 83, 90 and 105 days after sowing) were randomly selected 52 plants, totaling 520 plants. In each plant, were measured the characters plant height, number of leaves and number of tillers, and fresh and dry masses. The sigmoidal model was adjusted and it was studied the relations among the traits by correlation and path analysis. In the culture of black oat, the number of leaves per plant and plant height has a positive linear relation with the fresh and dry masses of shoots and can be used for indirect selection.

Relações lineares entre caracteres de aveia preta / Linear relations among characters of black oat

É importante estudar as relações lineares entre os caracteres para a seleção indireta de plantas. O objetivo deste trabalho foi avaliar as relações lineares entre caracteres de aveia preta (Avena strigosa Schreb) e identificar caracteres para a seleção indireta. Foi conduzido experimento a campo e, em dez épocas de avaliação (22, 28, 34, 42, 48, 55, 76, 83, 90 e 105 dias após a semeadura), foram selecionadas, aleatoriamente, 52 plantas, totalizando 520 plantas. Em cada planta, foram mensurados os caracteres altura de planta, números de folhas e de perfilhos e as massas verde e seca. Foi ajustado o modelo sigmoidal e investigada a relação entre os caracteres por meio de análises de correlação e de trilha. Na cultura de aveia preta, o número de folhas por planta e a altura de planta têm relação linear positiva com as massas verde e seca e podem ser utilizados para seleção indireta.(AU)

It is important to study the linear relations among characters for indirect selection of plants. The objective of this paper was to evaluate the linear relations among characters of black oat (Avena strigosa Schreb) and identify characters for indirect selection. Field experiment was conducted and in ten evaluation times (22, 28, 34, 42, 48, 55, 76, 83, 90 and 105 days after sowing) were randomly selected 52 plants, totaling 520 plants. In each plant, were measured the characters plant height, number of leaves and number of tillers, and fresh and dry masses. The sigmoidal model was adjusted and it was studied the relations among the traits by correlation and path analysis. In the culture of black oat, the number of leaves per plant and plant height has a positive linear relation with the fresh and dry masses of shoots and can be used for indirect selection.(AU)

Pathway analyses in wheat genotypes under waterlogging stress / Análise de trilha em genótipos de trigo submetidos ao estresse por encharcamento

Indirect selection can be considered an interesting strategy for plant breeding, especially when an easily measurable/high heritability trait is highly correlated with a target trait which has a lower heritability in segregating populations. The objective of this study was to obtain estimates of phenotypic, genotypic and environmental correlations and to evaluate the partition of genotypic correlations in direct and indirect effects of agronomic variables on the GY variable, through the analysis of two cultivated environments in fifteen wheat segregating populations. The agronomic traits grain yield per plant (GY), number of grains per ear (NGE), grain weight per ear (GWE), thousand grain weight (TGW), number of fertile tillers (NFT), days from emergence to flowering (DEF), days from flowering to maturity (DFM), total development cycle (CYC), and percentage of lodging (LODG), were evaluated in F4 populations under two cropping systems (with and without flooding). In all populations, by means of simple correlations, the selection of more productive plants can be accomplished by indirect selection for NGE, GWE and NFT. Through path analysis, it was possible to identify an indirect effect on GY by NGE. Also, the effect of GWE, NFT, CYC and DEF on the correlation between other characters (NGE x GY, GY x WTG, DFM x GY, GY x CYC and GY x LODG), emphasizing that the NGE, GWE, NFT, DEF and CYC are the main characters to consider for increasing grain yield in wheat.(AU)

A seleção indireta pode ser considerada uma estratégia interessante para o melhoramento de plantas, especialmente quando um caráter de fácil mensuração ou de maior herdabilidade estiver altamente correlacionado com um caráter de interesse, que apresente menor herdabilidade em populações segregantes. Os objetivos deste trabalho consistiram em obter estimativas de coeficientes de correlação fenotípica, genotípica e ambientais e avaliar os desdobramentos das correlações genotípicas em efeitos diretos e indiretos de variáveis agronômicas sobre o rendimento de grãos por meio da análise de dois ambientes de cultivo em quinze populações segregantes de trigo. Os caracteres agronômicos rendimento de grãos por planta (RG), número de grãos por espiga (NGE), peso dos grãos por espiga (PGE), massa de mil grãos (MMG), número de afilhos férteis (NAF), dias da emergência ao florescimento (DEF), dias do florescimento à maturação (DFM), ciclo total de desenvolvimento (CICLO), e acamamento (ACAM), foram avaliados em quinze populações segregantes F4 de trigo sob dois sistemas de cultivo (com e sem encharcamento). Em todas as populações avaliadas, por meio das correlações simples, a seleção de plantas mais produtivas pode ser realizada pela seleção indireta sobre NGE, PGE e NAF. Mediante a análise de trilha foi possível identificar o efeito indireto do caráter NGE sobre RG. Assim como o efeito do PGE, do NAF, do DEF e de CICLO como causadores da formação da correlação entre outros caracteres (NGE x RG, MMG x RG, de DFM x RG, de CICLO x RG e de ACAM x RG), enfatizando que o NGE, o PGE, o NAF, o DEF e que o CICLO são os principais caracteres a serem considerados para aumentar a produtividade de grãos em trigo.(AU)

Relações lineares entre caracteres de nabo forrageiro e de tremoço branco / Linear relations among characters of forage turnips and of white lupine

O objetivo deste trabalho foi avaliar as relações entre caracteres de nabo forrageiro (Raphanus sativus L.) e de tremoço branco (Lupinus albus L.), e identificar caracteres para a seleção indireta. Foi conduzido um experimento com nabo forrageiro e outro com tremoço branco, em Santa Maria, Estado do Rio Grande do Sul (latitude 29°42'S, longitude 53°49'W e 95m de altitude). Na colheita, foram mensurados a altura de planta, o diâmetro de caule, o número de folhas e as massas verde e seca de parte aérea em 300 plantas de nabo forrageiro e a altura de planta, o diâmetro de caule, o número de vagens e as massas verde e seca de parte aérea em 400 plantas de tremoço branco. Foi investigada a relação entre os caracteres por meio de diagramas de dispersão e análises de correlação e de trilha. Na cultura de nabo forrageiro, o diâmetro de caule tem relação linear positiva com as massas verde e seca e pode ser utilizado para seleção indireta. Na cultura de tremoço branco, o número de vagens por planta tem relação linear positiva com as massas verde e seca e pode ser utilizado para seleção indireta.

The objective of this paper was to evaluate the relationships among characters in forage turnips (Raphanus sativus L.) and white lupine (Lupinus albus L.), and identify character for indirect selection. An experiment was conducted with forage turnips and another with white lupine, in Santa Maria, Rio Grande do Sul State, Brazil (latitude 29°42'S, longitude 53°49'W and 95m altitude). At harvest, were measured plant height, stem diameter, leaf number and fresh and dry masses of shoots in 300 plants of forage turnips and plant height, stem diameter, number of pods and the fresh and dry masses of shoots in 400 plants of white lupine. It was studied the relationship among the traits by scatter plots, correlation and path analysis. In the culture of forage turnips the stem diameter has a positive linear relationship with the fresh and dry masses of shoots and can be used for indirect selection. In the culture of white lupine the number of pods has a positive linear relationship with the fresh and dry masses of shoots and can be used for indirect selection.

Relações lineares entre caracteres de nabo forrageiro e de tremoço branco / Linear relations among characters of forage turnips and of white lupine

O objetivo deste trabalho foi avaliar as relações entre caracteres de nabo forrageiro (Raphanus sativus L.) e de tremoço branco (Lupinus albus L.), e identificar caracteres para a seleção indireta. Foi conduzido um experimento com nabo forrageiro e outro com tremoço branco, em Santa Maria, Estado do Rio Grande do Sul (latitude 29°42'S, longitude 53°49'W e 95m de altitude). Na colheita, foram mensurados a altura de planta, o diâmetro de caule, o número de folhas e as massas verde e seca de parte aérea em 300 plantas de nabo forrageiro e a altura de planta, o diâmetro de caule, o número de vagens e as massas verde e seca de parte aérea em 400 plantas de tremoço branco. Foi investigada a relação entre os caracteres por meio de diagramas de dispersão e análises de correlação e de trilha. Na cultura de nabo forrageiro, o diâmetro de caule tem relação linear positiva com as massas verde e seca e pode ser utilizado para seleção indireta. Na cultura de tremoço branco, o número de vagens por planta tem relação linear positiva com as massas verde e seca e pode ser utilizado para seleção indireta.(AU)

The objective of this paper was to evaluate the relationships among characters in forage turnips (Raphanus sativus L.) and white lupine (Lupinus albus L.), and identify character for indirect selection. An experiment was conducted with forage turnips and another with white lupine, in Santa Maria, Rio Grande do Sul State, Brazil (latitude 29°42'S, longitude 53°49'W and 95m altitude). At harvest, were measured plant height, stem diameter, leaf number and fresh and dry masses of shoots in 300 plants of forage turnips and plant height, stem diameter, number of pods and the fresh and dry masses of shoots in 400 plants of white lupine. It was studied the relationship among the traits by scatter plots, correlation and path analysis. In the culture of forage turnips the stem diameter has a positive linear relationship with the fresh and dry masses of shoots and can be used for indirect selection. In the culture of white lupine the number of pods has a positive linear relationship with the fresh and dry masses of shoots and can be used for indirect selection.(AU)

Pathway analyses in wheat genotypes under waterlogging stress / Análise de trilha em genótipos de trigo submetidos ao estresse por encharcamento

Indirect selection can be considered an interesting strategy for plant breeding, especially when an easily measurable/high heritability trait is highly correlated with a target trait which has a lower heritability in segregating populations. The objective of this study was to obtain estimates of phenotypic, genotypic and environmental correlations and to evaluate the partition of genotypic correlations in direct and indirect effects of agronomic variables on the GY variable, through the analysis of two cultivated environments in fifteen wheat segregating populations. The agronomic traits grain yield per plant (GY), number of grains per ear (NGE), grain weight per ear (GWE), thousand grain weight (TGW), number of fertile tillers (NFT), days from emergence to flowering (DEF), days from flowering to maturity (DFM), total development cycle (CYC), and percentage of lodging (LODG), were evaluated in F4 populations under two cropping systems (with and without flooding). In all populations, by means of simple correlations, the selection of more productive plants can be accomplished by indirect selection for NGE, GWE and NFT. Through path analysis, it was possible to identify an indirect effect on GY by NGE. Also, the effect of GWE, NFT, CYC and DEF on the correlation between other characters (NGE x GY, GY x WTG, DFM x GY, GY x CYC and GY x LODG), emphasizing that the NGE, GWE, NFT, DEF and CYC are the main characters to consider for increasing grain yield in wheat.

A seleção indireta pode ser considerada uma estratégia interessante para o melhoramento de plantas, especialmente quando um caráter de fácil mensuração ou de maior herdabilidade estiver altamente correlacionado com um caráter de interesse, que apresente menor herdabilidade em populações segregantes. Os objetivos deste trabalho consistiram em obter estimativas de coeficientes de correlação fenotípica, genotípica e ambientais e avaliar os desdobramentos das correlações genotípicas em efeitos diretos e indiretos de variáveis agronômicas sobre o rendimento de grãos por meio da análise de dois ambientes de cultivo em quinze populações segregantes de trigo. Os caracteres agronômicos rendimento de grãos por planta (RG), número de grãos por espiga (NGE), peso dos grãos por espiga (PGE), massa de mil grãos (MMG), número de afilhos férteis (NAF), dias da emergência ao florescimento (DEF), dias do florescimento à maturação (DFM), ciclo total de desenvolvimento (CICLO), e acamamento (ACAM), foram avaliados em quinze populações segregantes F4 de trigo sob dois sistemas de cultivo (com e sem encharcamento). Em todas as populações avaliadas, por meio das correlações simples, a seleção de plantas mais produtivas pode ser realizada pela seleção indireta sobre NGE, PGE e NAF. Mediante a análise de trilha foi possível identificar o efeito indireto do caráter NGE sobre RG. Assim como o efeito do PGE, do NAF, do DEF e de CICLO como causadores da formação da correlação entre outros caracteres (NGE x RG, MMG x RG, de DFM x RG, de CICLO x RG e de ACAM x RG), enfatizando que o NGE, o PGE, o NAF, o DEF e que o CICLO são os principais caracteres a serem considerados para aumentar a produtividade de grãos em trigo.