ABSTRACT The objectives were to estimate the potential of S2 corn progenies for forage-related traits, and use of AMMI analysis to evaluate topcrosses compared to the classic analyzes. Progenies were crosses with four different testers: LG 6030, 2B688, 9.H3.33 and 53F.P37. Topcross hybrids were evaluated in four 9 x 9 simple square lattice design, during the 2017/18 season at Maringa, Parana State. Grain yield, forage fresh matter yield, and forage dry matter yield were measured. Classical approach was composed by variance components, general and specific combining ability, whereas AMMI analysis was performed for progenies x testers interaction, considering additive main effects and multiplicative effects. Considering the classical approach, testers LG 6030 and 2B688 better expressed the genetic variability between progenies for grain yield. AMMI analysis allowed the partitioning of the sum of squares in additive main effects and multiplicative effects, being a complementary result for the classical approach. Progeny 14 was selected due to higher general combining ability for grain yield, forage fresh matter and forage dry matter yield. Topcrosses 14x9.H3.33 and 14x2B688 were selected due to their higher specific combining ability, additive and multiplicative effects. The AMMI analysis was effective and helped in the interpretation of the results.

Abstract This study aimed to apply, in unprecedented depth, a Bayesian approach to the non-linear regression model developed by Toler for evaluating the stability and adaptability of genotypes. Twenty-five soybean cultivars were evaluated in twenty-one plots across the midwestern of Brazil. A complete block design was employed, with three replications. The evaluated variable was grain yield. The proposed methodology was implemented in the R program by means of the BRugs package. The methodology was capable of differentiating the effect of the environment on soybean cultivars in terms of yield in the different environments, allowing exploration of the response of each genotype to environmental variations. Cultivars 6266RSF, NS6990, GD19I435, GD19I439, GD19C443, RC0496 and IA18661 presented good stability and general adaptability, being the most recommended for future evaluations. The other cultivars presented specific adaptability and high responsiveness to unfavorable environments. apply depth nonlinear non linear genotypes Twentyfive Twenty five twentyone twenty one Brazil employed replications package environments variations 6266RSF RSF NS6990 NS GD19I435 GDI GD I GD19I439 GD19C443 GDC C RC RC049 IA IA1866 evaluations NS699 GD19I43 GD19C44 RC04 IA186 NS69 GD19I4 GD19C4 RC0 IA18 NS6 GD19I GD19C IA1

ABSTRACT The development of new popcorn cultivars that include wide adaptation, high stability and superior performance characteristics is one of the main alternatives to mitigate the effects of the genotype × environment interaction. In this sense, our main goal was to evaluate the adaptability and stability of new popcorn hybrids using Bayesian additive main effects and multiplicative interaction (BAMMI) method for grain yield (GY) and popping expansion capacity (PE) traits. We evaluated GY and PE from 45 new popcorn hybrids and three commercial cultivars (IAC–125, Pop Top and Top Ten) as checks in six different environments. Genotype × environment interaction, correlation and stability analyses were performed using Bayesian approaches. The full models tested presented the lowest deviance information criterion (DIC) values when compared to null models, indicating the presence of the genotype × environment interaction for both evaluated agronomic traits. Negative correlations were observed between GY and PE (r = –0.24, 95% highest posterior density [HPD] = –0.31; –0.17) and confirm the difficulty to perform selection simultaneously for both characteristics. UEM–3 and UEM–7 hybrids showed wide stability and high a posteriori averages for GY and PE. Both cultivars can be registered and recommended for cultivation in popcorn producing regions.

ABSTRACT. In this study, we aimed to estimate general and specific combining abilities (GCA and SCA, respectively) and to verify genetic divergence (Rogers distance, Unweighted Pair-Group Method Using Arithmetic Average - UPGMA) using microsatellite markers in maize inbred lines. Using a partial diallel scheme, a total of 19 inbred lines were crossed as (9 x 10), which were derived from the single hybrids SG6015 and P30F53, respectively. The 90 hybrids were evaluated in an incomplete randomized block design with common checks and three replications during the 2017-2018 growing season. Flowering time, average plant height, ear height insertion, average ear diameter, ear length, number of lodged and broken plants, mass of 100 grains and grain yield were measured. According to the analysis of variance, GCA, and SCA were significant (p < 0.05) in all the measured traits; inbred line B as well as 1 and 8, derived from the single hybrids SG6015 and P30F53, respectively, were selected due to their higher GCA values in grain yield to be used in crosses as testers, while the single cross hybrid (B x 1) was selected due to their higher SCA value in grain yield to be used in future breeding programs. The molecular marker analysis divided the inbred lines into two groups, where the highest dissimilarity (0.74) was observed between lines A and 9; however, these did not result in a high SCA value, therefore the hybrids obtained by such crossings were not selected for grain yield.

ABSTRACT The objective of this study was to conduct a meta-analysis and test its efficiency in summarizing the heterogeneous data of heritability estimates for the traits of grain yield (GY) and popping expansion (PE), and to provide reliable estimates of selection gains in popcorn. Therefore, 97 heritability estimates (ĥ 2) for popcorn GY and PE in the broad and narrow sense were used. The main procedures underlying the estimation of the combined heritability (ĥ 2 + ) using the technique of meta-analysis consisted of i) an exploratory analysis of the set of heritability estimates to detect outliers using a box-plot chart, ii) the verification of the required statistical assumptions, iii) testing the involved heritability estimates for homogeneity, and iv) the calculation of the estimates of combined heritability. The meta-analysis facilitated the synthesis of the information pertaining to heritability in popcorn. The combined heritability estimates (ĥ 2 + ) in the broad sense for GY and PE were 0.5208 ± 0.0229 and 0.6356 ± 0.0209, respectively, and in the narrow sense were 0.3290 ± 0.0292 and 0.3083 ± 0.0298, respectively.

ABSTRACT. Our objectives were to evaluate general and specific combining ability (SCA) and genetic divergence among tropical maize inbred lines using single sequence repeat (SSR) markers. Thirteen inbred lines were crossed based on a complete diallel scheme. Hybrids and three checks were evaluated in a lattice experimental design. Silk and anthesis flowering, average plant height, average ear height, white spot (Pantoea ananatis) and gray leaf spot (Cercospora zeae-maydis) severity, and grain yield were evaluated. Significant differences (p < 0.05) for general and specific combining abilities were observed for all traits. Based on additive effects, inbred lines 1 (Flash) and 12 (SG 6015) were selected to reduce the flowering period and plant and ear height. Inbred lines 2 (CD 303) and 3 (AG 8080) were selected to reduce disease severity. For the simultaneous increase in grain yield and reduced severity of diseases, line 11 (AG 9090) as a parent or tester in topcross schemes is recommended. According to non-additive effects, crosses 2 (CD 303) × 13 (DKB 747) and 11 (AG 9090) × 12 (SG 6015) were selected for grain yield and future breeding programs. Six groups were identified using SSR markers; a major group contained six inbred lines. Because of the minor relationship between genetic divergence and SCA effects on grain yield limits, the use of the groups for future divergent crosses is recommended.

ABSTRACT The objective of this study was to estimate the varietal and heterotic effects related to grain yield, popping expansion and resistance of popcorn against fall armyworm. Twelve open-pollinated varieties were intercrossed in a complete diallel mating scheme. The 66 experimental hybrids, together with their parents and controls Zapalote Chico, BRS 1030 and IAC 125, resulted in a total of 81 treatments, evaluated in an experiment in a 9x9 triple-square lattice design, in Maringá-PR and Araruna-PR. The data were analyzed according to the diallel model of Gardner and Eberhart (1966). The following traits were evaluated: grain yield (GR); mean plant height (PH) and insertion height of the highest ear in the stem (EI); silking (SIL); final plant density (FD) and popping expansion (PE). Variety PR 023 is indicated for intrapopulation improvement for grain yield. Regarding popping expansion, the results indicated cross SAM x UNB 2U C5 for recurrent reciprocal selection. In relation to resistance to fall armyworm, the varieties PARA 172, PA 091, PR 023, and SE 013 were selected for intrapopulation improvement. On the other hand, the crosses PARA 172 x BOZM 260, PA 091 x BOYA 462 and SAM x UNB 2U C5 can be indicated for interpopulation improvement.

Resumo: O objetivo deste trabalho foi avaliar as influências dos fatores genótipos de milho (Zea mays), safras agrícolas, texturas dos endospermas, fundo genético e bases genéticas nas taxas de haploides putativos (THPs), conforme a expressão do gene R1-navajo (R1-nj). Foram avaliados 41 genótipos de milho como receptores de pólen, em cruzamentos com o indutor “Krasnodar haploid inducer”, em duas safras (verão e inverno), no município de Maringá, no estado do Paraná, Brasil. O delineamento experimental foi o inteiramente casualizado com dez repetições (espigas). A variável resposta analisada foi a THP determinada pela proporção de haploides putativos, obtidos com base no marcador R1-nj, em relação ao número de sementes diploides por espiga. Posteriormente, foram utilizados modelos lineares generalizados para escolher o mais adequado para explicar a THP em função dos fatores testados. As safras, os genótipos e a interação safras x genótipos afetaram significativamente a THP, o que evidencia a dependência destes fatores na expressão do marcador fenotípico baseado na pigmentação por antocianina e determinado pelo gene dominante R1-nj. O número de agrupamentos formados pelos genótipos foram diferentes em cada safra. Dez genótipos apresentaram taxas maiores no verão do que no inverno. As texturas dos endospermas, as bases genéticas e o fundo genético não interferiram na THP.

Abstract: The objective of this work was to evaluate the influences of the factors corn (Zea mays) genotypes, crop seasons, endosperm texture, genetic background, and genetic basis on putative haploid rates (PHRs) according to the expression of gene R1-navajo (R1-nj). Forty-one corn genotypes were evaluated as pollen receptors, in crosses with the Krasnodar haploid inducer, in two crops (summer and winter), in the municipality of Maringá, in the state of Paraná, Brazil. The experimental design was completely randomized with ten replicates (ears). The response variable analyzed was the PHR, determined by the proportion of putative haploids, obtained through the R1-nj marker, in relation to the number of diploid seeds in each ear. Subsequently, generalized linear models were used to choose the one best fit to explain the PHR in function of the tested factors. Crop seasons, genotypes, and the crop seasons x genotypes interaction affected significantly the PHR, showing the dependence of these factors on the expression of the phenotypic marker based on anthocyanin pigmentation and determined by gene R1-nj. The number of clusters formed by the genotypes was different in each crop season. Ten genotypes showed higher rates in summer than in winter. Endosperm texture, genetic basis, and genetic background did not affect the PHR.

RESUMO: O presente trabalho teve como objetivo avaliar o desempenho de testadores quanto à capacidade de discriminação de linhagens tropicais convertidas à superdoce, por meio da incorporação do gene shrunken (sh2), visando a produção de híbridos adaptados às condições tropicais. As linhagens utilizadas como parentais femininos foram os testadores: variedade de polinização aberta Mista; linhagem superdoce L4; híbrido comercial superdoce Tropical Plus. Os quatro experimentos foram conduzidos em Maringá - PR e Sabáudia - PR, na safra verão de 2015/16. As características avaliadas foram: Peso de espigas totais (PET, em kg), Peso de espigas comerciais (PEC, em kg) e sólidos solúveis totais (SST, em ºBrix). A linhagem L4 foi o testador que mais proporcionou efeito de heterose. As maiores estimativas de CGC para PET e PEC foram obtidas por L4. As linhagens Balu-114 e UEM-25 foram selecionados com base nos efeitos de g ̂ i para as características estudadas e deverão ser utilizados na formação de populações base para a extração de linhagens superiores. O cruzamento BALU-182 x Tropical apresentou o maior valor de s ̂ ijpara PET, enquanto o cruzamento BALU-94 x Mista obteve o melhor valor para PEC.

ABSTRACT: The purpose of this study was to evaluate the discriminatory capacity of tester lines for tropical corn lines converted to supersweet shrunken (sh2) gene, for the development of hybrids adapted to tropical conditions. Lines were used as female parents in crosses with three testers: open-pollinated mixed variety; supersweet line L4; supersweet commercial hybrid Tropical Plus. Four trials were carried out to evaluate topcrosses in Maringá - PR e Sabáudia - PR, Brazil in the main growing season of 2015/16. The following traits were evaluated: total ear weight (TEW, in kg), commercial ear weight (CEW, in kg) and total soluble solids (TSS, in °Brix). The GCA estimates for TEW and CEW were highest for L4. The lines Balu-114 and UEM-25 were selected based on the effects of g ̂ ifor the traits studied and should be used in the establishment of base populations for the breeding of superior lines. The s ̂ ijvalue for TEW was highest for cross BALU-182 x Tropical, while for CEW was the highest value for cross BALU-94 x Mista.

Abstract Comparison between two distinct groups using a partial diallel and considering reciprocal effects has not been described in the scientific literature, limiting diallel analysis results. This study compared two groups of parents using a partial diallel, and analyzed the general and specific combining ability and reciprocal effects, divided into maternal and cytoplasmic. A partial diallel was established with nine maize hybrids, including the F1 and reciprocal hybrids for grain yield. For this application, the reciprocal effects were not significant. The proposed model would provide plant breeders with additional information to analyze partial diallel mating designs.

RESUMO: O trabalho teve por objetivo avaliar a depressão por endogamia e os componentes genéticos de médias em sete híbridos e em duas variedades de polinização aberta para uso como milho verde, para seleção de genótipos visando à formação de populações-base para a extração de linhagens. Para a realização do estudo, foi instalado um experimento no município de Sabáudia - PR, no ano agrícola de 2014/15. O experimento foi delineado em blocos completos ao acaso, com quatro repetições, em arranjo de parcelas subdivididas, com as gerações de endogamia e os diferentes genótipos ocupando as parcelas e as subparcelas, respectivamente. As maiores estimativas de dominância e de depressão endogâmica foram observadas na produtividade de espigas empalhadas e comerciais. Os efeitos aditivos foram mais expressivos na herança do comprimento e do diâmetro de espigas comerciais. Os genótipos AM811, Cativerde 02 e AG4051 apresentaram maiores probabilidades no sucesso de extração de linhagens destinadas à produtividade e qualidade de milho verde.

ABSTRACT: This study aimed to evaluate the inbreeding depression and average genetic components in seven hybrids and two open pollinated cultivars for green corn production, as well as to select the best genotypes in order to obtain base populations for inbred lines extraction. The experiment was carried out in a randomized complete block design with four replications, in a split plot design, with inbreeding levels arranged in the plots and the different genotypes distributed over the subplots, in the municipality of Sabáudia - PR, during the 2014/15 crop season. Higher values of dominance and inbreeding depression were observed for yield of both unhusked and commercial ears. Higher additive effects were detected on length and diameter of commercial ears. The genotypes AM811, Cativerde 02 and AG4051 showed greater probability of obtaining highly productive and higher quality green corn inbred lines.

RESUMO Trinta e oito famílias S3 obtidas por autofecundação do híbrido de milho pipoca IAC-125 foram avaliadas por três diferentes testadores em cruzamentos topcrosses: a linhagem P3.3 em S7 obtida da população de milho pipoca CMS-42, BRS Angela que é uma variedade de polinização aberta e o híbrido triplo comercial Jade. Cruzamentos manuais foram realizados conforme o esquema de cruzamentos de um dialelo parcial. Os híbridos topcrosses foram avaliados em experimentos individuais para cada testador, no delineamento de blocos casualizados com três repetições, em dois locais (Maringá e Sabáudia). Os resultados obtidos para a produtividade de grãos e capacidade de expansão foram reunidos em uma análise conjunta para locais. As estimativas de capacidade geral e específica de combinação foram realizadas de acordo com a metodologia proposta por Griffing (1956), adaptada por Geraldi e Miranda Filho (1988). O híbrido Jade foi considerado o testador mais adequado porque discriminou melhor as famílias avaliadas de acordo com o índice Fasoulas de diferenciação, tanto para a produtividade de grãos quanto para capacidade de expansão. As famílias F4, F7, F16 e F31 se mostraram como as mais promissoras devido à alta capacidade geral de combinação para as duas características, independentemente do local avaliado.

ABSTRACT Thirty-eight S3 families obtained by selfing from IAC-125 popcorn hybrid were evaluated by three different topcross tester parents: an inbred line P3.3- S7 generation taken from popcorn population CMS-42, an open-pollinated variety BRS Angela and the commercial three-way hybrid Jade. Manual crossings were performed according to a partial diallel mating design. Topcross hybrids were evaluated in individual experiments for each tester carried out in randomized block designs with three replications in two locations (Maringá-Paraná and Sabáudia-Paraná). The results for grain yield and popping expansion were gathered in a combined analysis. Estimates of general and specific combining ability were obtained according to Griffing's methodology (1956), adapted by Geraldi and Miranda Filho (1988). The hybrid Jade was considered the most appropriate tester because it discriminated the evaluated families well for both grain yield and popping expansion according to Fasoulas index of differentiation. Families F4, F7, F16 and F31 are the most promising due to their high general combining ability for both traits as well their performance regardless of the effect of locations.

Resumo Com o objetivo de avaliar o potencial genético de milho branco para canjica, foram avaliados 28 híbridos resultantes de cruzamentos dialélicos entre oito genitores, incluindo os parentais e as gerações S1. Foram estimadas as capacidades combinatórias e os níveis de heterose e depressão endogâmica. Os genitores utilizados foram os principais híbridos de milho branco pertencentes ao germoplasma brasileiro. As combinações HT 9332 x HT 392, IAC Nelore x HT 9332, IAC Nelore x HT 932 e IPR 119 x IAC Nelore são promissoras para programas de seleção recorrente recíproca para maior rendimento de grãos. O híbrido IPR 127 foi indicado como fonte de linhagens com características industriais favoráveis ao canjicamento. O híbrido IAC Nelore apresentou a menor estimativa de depressão por endogamia e foi recomendado para a extração de linhagens e participação em híbridos e compostos mais produtivos.

Abstract To assess the genetic potential of white corn for corn grits, 28 hybrids resulting from diallel crosses of eight parents, including parents and S1 generations, were evaluated. The combining abilities and levels of heterosis and inbreeding depression were estimated. The parents used were the main white maize hybrids of the Brazilian germplasm. The combinations HT 9332 x HT 392, IAC Nelore x HT 9332, IAC Nelore x HT 932, and IPR 119 x IAC Nelore are promising for reciprocal recurrent selection programs targeting higher grain yield. Hybrid IPR 127 was indicated as a source of industrial lines with favorable traits for dry-rolled corn production. Hybrid IAC Nelore had the lowest estimate of inbreeding depression and was recommended for the breeding of lines and participation in higher-yielding hybrids and composites.

Este trabalho teve como objetivo estimar a capacidade combinatória e a depressão endogâmica de híbridos de milho para caracteres agronômicos e qualidade de forragem. Foram avaliados nove híbridos de milho, 36 combinações F1 oriundas de um dialelo, nove populações S1 e duas testemunhas, em dois experimentos delineados em blocos completos ao acaso com três repetições, nas safras 2009/2010 e 2010/2011. Os genitores Impacto, CD304 e DKB390 são recomendados para a formação de um composto a ser submetido a um programa de seleção recorrente visando à melhoria na produção de forragem. Os cruzamentos entre o genitor Impacto e os parentais DKB390, P30P34 e P30B39 são promissores à melhoria da qualidade da forragem por meio da redução nos teores de fibra e aumento de proteína, sendo recomendados para extração de linhagens ou melhoramento interpopulacional. Foi detectada uma alta depressão endogâmica para rendimento de grãos, indicando que efeitos não aditivos contribuíram para a herança do caráter.

This study aimed to estimate the combining ability and inbreeding depression of corn hybrids for agronomic traits and forage quality. Nine corn hybrids, 36 F1 combinations from a diallel, 9 S1 populations and two checks were evaluated in two experiments in a randomized complete block design with three replications, in the 2009/2010 and 2010/2011 growing seasons. The parents Impacto, CD304 and DKB390 are recommended to form a composite to be subjected to a recurrent selection program aiming to improve forage production. Crosses between Impacto and parents DKB390, P30P34 and P30B39 are promising to increase forage quality by reducing the fiber content and also by increasing the protein content, being recommended for extracting inbred lines and interpopulation improvement. High inbreeding depression for grain yield was detected, indicating that non-additive effects contributed to the inheritance of the trait.

O presente trabalho teve como objetivos investigar a capacidade combinatória e o efeito heterótico de linhagens tropicais e temperadas sobre o rendimento de grãos (RG), teor de óleo (TO) e proteína (PB). Os híbridos e as linhagens foram avaliados a partir de um dialelo completo, sem recíprocos, em dois experimentos delineados em blocos casualizados com três repetições. O desdobramento da soma de quadrado de genótipos em soma de quadrados para capacidade geral (CGC) e específica (CEC) de combinação e a subsequente constatação de significância de CGC e de CEC evidenciaram que tanto efeitos aditivos quanto não-aditivos estiveram envolvidos no controle genético das características avaliadas. Pelas estimativas dos componentes quadráticos, houve superioridade dos efeitos genéticos não-aditivos no controle das características. Contudo, percebe-se que para PB e TO o efeito não-aditivo influenciou negativamente as combinações híbridas. O cruzamento L6x L10foi considerado promissor, pois associou positivamente RG com PB e TO.

This study aimed to investigate the combining ability and heterotic effects on grain yield (GY), oil content (OC) and crude protein (CP) in tropical and temperate maize lines. Hybrids and inbred lines were evaluated in a complete diallel scheme without reciprocals, in two experiments in randomized blocks with three replications. The partitioning of the sum of squares for general (GCA) and specific (SCA) combining ability indicated that both additive and non-additive effects were involved in the genetic control of the studied traits. The estimates of the quadratic components showed predominance of non-additive genetic effects in the trait control. However, for OC and CP, the non-additive effect had a clearly negative influence on the hybrid combinations. The cross L6x L10was considered promising, because it associated RG positively with BP and OC.