ABSTRACT A large set of variables is assessed for progeny selection in a plant-breeding program and other agronomic fields. The meta-analysis of the coefficient of variation (CVe) produces information for researchers and breeders on the experimental quality of trials. This analysis can also be applied in the decision-making process of the experimental plan regarding the experimental design, the number of repetitions, and the treatments and plants/progenies to be measured. In this study, we evaluated the dataset distribution and the descriptive statistics of CVe through the Frequentist and Bayesian approaches, aiming to establish the credibility and confidence intervals. We submitted CVe data of ten wheat (Triticum aestivum L.) traits reported in 1,068 articles published to the Bayesian and Frequentist analyses. Sample data were analyzed via Gamma and normal models. We selected the model with the lowest Akaike Information Criterion (AIC) value, and then we tested three link functions. In the Bayesian analysis, uniform distributions were used as non-informative priors for the Gamma distribution parameters with three ranges of q~U (a,b,). Thus, the prior probability density function was given by: p θ = 1 β - α , θ ∈ α , β . The Bayesian and Frequentist approaches with the Gamma model presented similar results for CVe; however, the range Bayesian credible intervals was narrower than the Frequentist confidence intervals. Gamma distribution fitted the CVe data better than the normal distribution. The credible and confidence intervals of CVe were successfully applied to wheat traits and could be used as experimental accuracy measurements in other experiments.

RESUMO: O processo de desenvolvimento de uma nova cultivar de trigo requer tempo entre a obtenção da população base e a seleção da linhagem mais promissora. Estimar parâmetros genéticos com mais precisão nas primeiras gerações com vistas a antecipar a seleção significa avanços importantes para os programas de melhoramento de trigo. Assim, o presente estudo estima os parâmetros genéticos de populações F2 de trigo tropical e o ganho genético da seleção via abordagem Bayesiana. Para tanto, os autores avaliaram a produtividade de grãos por parcela de 34 populações F2 de trigo tropical. A abordagem Bayesiana proporcionou um ajuste adequado ao modelo, estimando parâmetros genéticos dentro do espaço paramétrico. A herdabilidade (h2) foi de 0,51. Dentre as selecionadas, 11 populações F2 obtiveram desempenho superior às cultivares controle, com ganho genético de seleção de 7,80%. As seguintes populações foram as mais promissoras: Tbio Sossego/CD 1303, CD 1303/Tbio Ponteiro, BRS 254/CD 1303, Tbio Duque/Tbio Aton e Tbio Aton/CD 1303. A inferência Bayesiana pode ser usada para melhorar significativamente programas de melhoramento de trigo tropical.

ABSTRACT: The development process of a new wheat cultivar requires time between obtaining the base population and selecting the most promising line. Estimating genetic parameters more accurately in early generations with a view to anticipating selection means important advances for wheat breeding programs. Thus, the present study estimated the genetic parameters of F2 populations of tropical wheat and the genetic gain from selection via the Bayesian approach. To this end, the authors assessed the grain yield per plot of 34 F2 populations of tropical wheat. The Bayesian approach provided an adequate fit to the model, estimating genetic parameters within the parametric space. Heritability (h2) was 0.51. Among those selected, 11 F2 populations performed better than the control cultivars, with genetic gain of 7.80%. The following populations were the most promising: TbioSossego/CD 1303, CD 1303/TbioPonteiro, BRS 254/CD 1303, Tbio Duque/Tbio Aton, and Tbio Aton/CD 1303. Bayesian inference can be used to significantly improve tropical wheat breeding programs.

Abstract The selection of parents to originate promising base populations, as well as the knowledge of the gene effects controlling agronomic traits by means of diallel, are useful to drive genetic gains in Brazilian tropical wheat breeding programs. The goals of this study were to select tropical wheat parents with a high frequency of favorable alleles and segregating populations with high potential to originate superior progenies through partial diallel analysis. Thus, 14 parents were divided in two groups and crossed in a 7 × 7 partial diallel scheme to originate 49 F1 combinations. After obtaining F2 generation, the populations and the parents were evaluated in the field in the summer of 2021. Days for heading, plant height, rust and yellow spot resistance, and grain yield were evaluated. The data were subjected to partial diallel analysis. There were significant effects of general combining ability for all traits. The specific combining ability effect was significant for days for heading and plant height. The additive gene effects were predominant over the non-additive ones. The parents with the highest frequency of favorable alleles for the traits evaluated were selected in each group. Four populations with high genetic potential to originate superior progenies were selected.

RESUMEN La selección de poblaciones segregantes con potencial para derivar líneas es esencial para los programas de mejoramiento. El presente trabajo presenta el potencial de las poblaciones tropicales de trigo F2 (Triticum aestivum L.) generadas a partir de combinaciones de cruces dialélicos completos. Para ello, se combinaron ocho cultivares de trigo tropical en un diseño dialélico completo en 2019 después de multiplicar semillas Fj en invernadero y se evaluaron en campo las semillas de 56 poblaciones F2, más los ocho progenitores, en la cosecha de invierno de 2020 en un diseño reticular simple (8x8) en Vicosa, MG, Brasil. Se evaluaron las variables: severidad de la mancha amarilla (Pyrenophora triticirepentis), severidad del tizón (WHB) (Magnaporthe oryzae pathotype Triticum), número de días hasta embuchamiento, altura de la espiga y peso total de grano en la parcela. El análisis dialélico se realizó utilizando modelos mixtos para obtener los efectos de capacidad combinatoria general (GCA), capacidad combinatoria específica (SCA) y estimación de valores genotípicos de la población. El efecto aditivo predominó para el control de todas las variables, excepto para la altura de la espiga. Hubo mayores efectos de GCA para el conjunto de plantas madres progenitoras. La he-redabilidad, en sentido estricto, osciló entre 0.20 (tizón) y 0.66 (embuchamiento). Hubo efecto de la CGA materna para todas las variables, mientras que para la CGA paterna solo para número de días hasta embuchamiento y peso total de grano en la parcela. Las poblaciones derivadas de los cultivares TBIO Aton, TBIO Ponteiro y TBIO Sossego presentaron menor severidad de la enfermedad, mientras que las combinaciones de BRS 254, BRS 264 y BRS 394 presentaron un tiempo de maduración más temprano. Las combinaciones más promisorias para derivar líneas para el conjunto de variables evaluadas fueron BRS 254 x CD 1303, BRS 394 x TBIO Aton, TBIO Aton x BRS 254, CD 1303 x BRS 254 y CD 1303 x BRS 264.

ABSTRACT The selection of segregating populations with the potential for derived lines is essential for breeding programs. The present work analyzes the potential of tropical F2 wheat (Triticum aestivum L.) populations originated from complete diallel cross combinations. For this purpose, eight tropical wheat cultivars were combined in a complete diallel design in 2019 after Fj seeds were multiplied in a greenhouse and the seeds of 56 F2 populations, plus the eight parents, were evaluated in the field in Vicosa, MG, Brazil in the winter harvest of 2020 using a simple lattice design (8x8). The trait scores of (1) severity of tan spot (Pyrenophora triticirepentis), (2) severity of wheat head blast (WHB) (Magnaporthe oryzae pathotype Triticum), (3) days to heading, (4) spike height, (5) and total grain weight of the plot were evaluated. We performed a diallel analysis using mixed models to obtain the effects of general combining ability (GCA), specific combining ability (SCA), and estimation of population genotypic values. The additive effect predominated for the control of all traits, except for spike height. There were greater GCA effects for the set of parental maternal plants. Heritability, in the narrow sense, ranged from 0.20 (blast) to 0.66 (heading). There was an effect of maternal GCA for all variables, while for paternal GCA the effect was only for days passed for head and total grain weight. Populations derived from the cultivars TBIO Aton, TBIO Ponteiro, and TBIO Sossego had lower disease severity, while the combinations from BRS 254, BRS 264, and BRS 394 had earlier maturation time. The most promising combinations to derive lines for the set of traits were BRS 254 x CD 1303, BRS 394 x TBIO Aton, TBIO Aton x BRS 254, CD 1303 x BRS 254, and CD 1303 x BRS 264.

Abstract The improvement of superior wheat cultivars depends on the identification of promising segregating populations to derive superior lines. A lattice model (8×8) involving 56 F2 populations and eight parents was conducted in the 2020 cropping season, and grain yield per plant was evaluated for every F2 population, with further analysis of the population potential by Jinks and Pooni method via REML/BLUP. A total of 5,410 F2 plants were evaluated in this study. The results showed that the use of genetic variance associated with the individual genotypic value (BLUP) was superior compared with the use of variance and traditional phenotypic values. The F2 populations, CD 1303/BRS 254, CD 1303/Tbio Duque, CD 1303/Tbio Ponteiro, BRS 264/Tbio Aton, Tbio Ponteiro/Tbio Aton, and Tbio Sossego/CD 1303 had the highest likelihood of deriving superior lines.

Abstract Parent selection is a crucial step in breeding programs. In the present study, we evaluated the genetic diversity in tropical wheat genotypes using best linear unbiased predictions (BLUPs) by different grouping methods. We identified potential parents to compose a crossing block with the aim of improving wheat for the Brazilian Cerrado. A total of 41 tropical wheat genotypes were evaluated in a field experiment. The evaluated traits included days to flowering; disease symptoms of fusarium head blight, blast, and leaf rust; flag leaf height; plant height; spike mass; hectoliter weight; and grain yield. The BLUPs were predicted and, from these, the standardized average Euclidean distance was calculated. Then, UPGMA, Tocher, and principal component clusters were generated from this genotypic distance matrix. Evaluating genetic diversity based on BLUP allowed the identification of two groups of highly dissimilar genotypes with high estimated genotypic values with which to compose a partial diallel.

ABSTRACT. Beans can be found in different grain colours, and for this reason, it is important to understand the technological and nutritional quality of the diverse types of beans that are consumed. The objectives of this work were to identify the traits that determine Brazilian consumer choice of different bean colours and to evaluate whether different bean colours present differences in technological and nutritional traits. For this purpose, beans of different colours (white, cranberry, matte red kidney, shiny red kidney, and black) were obtained from supermarkets. The samples were evaluated for consumer preference and the technological and nutritional traits of the beans. In southern Brazil, the majority of the survey participants (58%) preferred black beans, and their choice was based on consumption habit (66%) and grain colour (30%). Different bean colours presented differences for all traits related to technological and nutritional quality, except for potassium concentration. Consumption habit and grain colour defined consumer choice for black beans. Black beans were preferred by 58% of the participants, and this type of bean has high concentrations of calcium, magnesium, iron, zinc and copper.

RESUMO. Estimativas de parâmetros genéticos para a concentração de ferro e zinco em sementes de feijão Andino foram obtidas usando os cruzamentos IAC Boreal × Light Red Kidney e Ouro Branco × Light Red Kidney. Os parentais e as gerações F1, F1 recíproco, F2, F2 recíproco e retrocruzamentos RC11 e RC12 foram avaliados em experimento de campo conduzido em Santa Maria, Estado do Rio Grande do Sul, Brasil. A concentração de ferro nas sementes de feijão Andino variou de 24,70 a 102,40 mg kg-1 de matéria seca - MS e a de zinco, de 10,73 a 37,50 mg kg-1 de MS, sem que expressão de efeito materno tem sido observada. A herdabilidade em sentido restrito foi de baixa (h2r= 19,04%) a alta (h2r= 63,60%) magnitude para a concentração de ferro e de zinco, respectivamente. Vigor híbrido e segregação transgressiva foram observados para a concentração de ferro e de zinco em sementes de feijão Andino. Na combinação híbrida IAC Boreal × Ligh Red Kidney é possível selecionar recombinantes para o programa de biofortificação de ferro e zinco. A partir das combinações híbridas testadas podem ser selecionados recombinantes com baixa concentração de ferro e de zinco nas sementes para atender os casos de necessidade de restrição desses minerais na alimentação.

ABSTRACT. The genetic parameter estimates of the iron and zinc concentrations in Andean common bean seeds were obtained using the IAC Boreal × Light Red Kidney and Ouro Branco × Light Red Kidney crosses. The parents and the F1, F1 reciprocal, F2, F2 reciprocal, and backcross BC11 and BC12 generations were evaluated in a field experiment that was carried out in the state of Rio Grande do Sul, Brazil. The iron concentration in Andean common bean seeds ranged from 24.70 to 102.40 mg kg-1 dry matter (DM), the zinc concentration ranged from 10.73 to 37.50 mg kg-1 DM, and no significant maternal effect was observed. The narrow-sense heritability ranged from low (h2n= 19.04%) to high (h2n= 63.60%) for the concentrations of iron and zinc, respectively. Hybrid vigor and transgressive segregation were observed for the iron and zinc concentrations in Andean common bean seeds. In the hybrid combination IAC Boreal × Light Red Kidney, it was possible to select recombinants for the iron and zinc biofortification program. From the tested hybrid combinations, recombinants with low iron and zinc concentrations in seeds could be selected to use when the diet needs to be restricted in those minerals.

O objetivo deste trabalho foi avaliar as principais diferenças no controle genético da concentração de ferro em sementes de feijão comum mesoamericano e andino, em gerações precoces, e selecionar recombinantes com alta concentração de ferro nas sementes. Foram obtidas as gerações F1, F1 recíproco, F2, F2 recíproco e de retrocruzamentos (RC11 e RC12), a partir de cruzamentos entre linhagens mesoamericanas (CNFP 10104 x CHC 01-175) e andinas (Cal 96 x Hooter). A expressão de efeito materno significativo foi observada no grupo gênico mesoamericano. A concentração de ferro foi maior no tegumento das sementes de feijão comum mesoamericano (54,61 a 67,92%) e no embrião das sementes de feijão comum andino (69,40 a 73,44%). Alta estimativa de herdabilidade no sentido amplo foi obtida para a concentração de ferro em sementes de feijão comum mesoamericano e andino. Ganhos com a seleção de maior magnitude, de 20,39 a 24,58%, são esperados nas sementes de feijão comum mesoamericano. A concentração de ferro nas sementes de feijão comum apresentou distribuição contínua em F2, o que é característico de herança quantitativa em feijão comum mesoamericano e andino. Recombinantes com alta concentração de ferro nas sementes podem ser selecionados nos híbridos de feijão comum mesoamericano e andino.

The objective of this work was to evaluate the main differences in the genetic control of the iron concentration in Mesoamerican and Andean common bean seeds, in early generations, and to select recombinants with a high iron concentration in the seeds. F1, F1 reciprocal, F2, F2 reciprocal, and backcross (BC11 and BC12) generations were produced by crosses between Mesoamerican (CNFP 10104 x CHC 01-175) and Andean (Cal 96 x Hooter) inbred lines. The expression of significant maternal effect was observed for the Mesoamerican gene pool. Iron concentration was higher in the seed coat of Mesoamerican common bean seeds (54.61 to 67.92%) and in the embryo of Andean common bean seeds (69.40 to 73.44%). High broad-sense heritability was obtained for iron concentration in Mesoamerican and Andean common bean seeds. Gains with the selection of higher magnitude, from 20.39 to 24.58%, are expected in Mesoamerican common bean seeds. Iron concentration in common bean seeds showed a continuous distribution in F2, which is characteristic of quantitative inheritance in Mesoamerican and Andean common bean seeds. Recombinants with high iron concentration in seeds can be selected in both Mesoamerican and Andean common bean hybrids.