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

RESUMO O milho pipoca é uma importante cultura agrícola, consumida como petisco pela população mundial. No Brasil, a falta de cultivares com alto potencial de rendimento de grãos e elevado volume de expansão é considerada uma das principais dificuldades. Nesse contexto, o presente trabalho teve como objetivo avaliar a divergência genética entre linhagens elite de milho pipoca por meio de marcadores AFLP (Amplified Fragment Length Polymorphism), estimar a capacidade geral e específica de combinação (GCA e SCA, respectivamente) e correlacionar a distância genética com a SCA e a média dos híbridos. Para o estudo de divergência genética, foram avaliadas 45 linhagens de milho pipoca provenientes de diferentes híbridos e variedades. Posteriormente, dez linhagens foram selecionadas para análise dialélica; o rendimento de grãos (GY) e a capacidade de expansão (PE) foram avaliados em três ambientes. Com base nos marcadores AFLP, foi observada uma ampla variabilidade entre as linhagens avaliadas. Na avaliação dos híbridos, foi observado efeito significativo para GY e PE, sendo que alguns híbridos apresentaram alto potencial de GY e PE quando comparados às testemunhas comerciais. Por meio da análise dialélica, foi observado efeito significativo da GCA para GY e PE, indicando que as linhagens diferem na frequência de alelos favoráveis, com linhagens promissoras para a formação de híbridos ou variedades sintéticas. Por outro lado, para SCA, nenhum efeito significativo foi observado para essas características. A distância genética não se correlacionou com GY e Ŝij, demonstrando ausência de consistência na predição de grupos heteróticos para milho pipoca via marcadores AFLP.

ABSTRACT Popcorn is an important agricultural crop that is consumed as a snack food worldwide. In Brazil, the lack of cultivars with high potential grain yield and popping expansion volume is a vital problem. Therefore, the present study aimed to evaluate the genetic divergence among elite popcorn lines using amplified fragment length polymorphism (AFLP) markers to estimate the general and specific combining ability (GCA and SCA, respectively), and correlate the genetic distance with the SCA and hybrid means. For the genetic divergence study, 45 popcorn inbred lines of different hybrids and varieties were evaluated. Subsequently, 10 inbred lines were selected for diallel analysis; grain yield (GY) and popping expansion (PE) were evaluated in three environments. A wide variability of popcorn inbred lines was observed based on the AFLP markers. After evaluating the hybrids, a significant effect was observed for GY and PE, with some experimental hybrids with higher potential GY and PE than the commercial cultivars. From the diallel analysis, a significant effect was observed for GCA for GY and PE; therefore, the lines differed in the frequency of favorable alleles, with promising inbred lines for forming hybrids or synthetic varieties. However, for SCA, no significant effect was observed for these traits. Genetic distance did not correlate with GY and Ŝij, demonstrating an absence of consistency in the prediction of heterotic groups for popcorn using AFLP markers.

RESUMO: A análise dos principais efeitos aditivos e interação multiplicativa é comumente utilizada na avaliação da interação genótipo x ambiente, porém, sua aplicação pode ser estendida para outros propósitos assim como realizado no presente trabalho em que utiliza esta técnica na seleção de linhagens, testadores e híbridos em topcrosses de milho. O objetivo deste trabalho foi determinar o efeito da interação linhagens x testadores por meio da análise dos principais efeitos aditivos e da interação multiplicativa, verificando sua eficiência na seleção de linhagens, testadoras e combinações híbridas em topcrosses. Os ensaios foram realizados nas safras 2015/16 e 2016/17, com delineamento em blocos completos, com três repetições. Trinta linhagens de milho S3 foram avaliadas em cruzamentos com os testadores AG8025, P30B39, MLP102, 60.H23.1 e 70.H26.1 formando 150 topcrosses híbridos. A característica avaliada foi a produtividade de grãos. A adaptabilidade e estabilidade de testadores e linhagens foram avaliadas pela metodologia de análise de efeitos aditivos principais e interação multiplicativa direcionada à interação testadores x linhagens. A linhagem 96.3 apresentou o desempenho mais homogêneo e o maior rendimento de grãos, considerando o cruzamento com todos os testadores em ambos os ambientes. O testador 70.H26.1 é considerado o mais estável e o mais recomendado para topcrosses. As melhores combinações específicas foram 96.3 x 70.H26.1 e 96.3 x 60.H23.1.

ABSTRACT: The analysis of main additive effects and multiplicative interaction is commonly used in the evaluation of the genotype x environment interaction, however, its application can be used for other purposes, as it is performed in the presentresearch, which uses this technique in the selection of inbred lines, testers and hybrids in maize topcrosses. Thisresearch determined the effect of the inbred lines x testers interaction through the analysis of main additive effects and multiplicative interaction, verifying their efficiency in the selection of inbred lines, testers and hybrid combinations in topcrosses. The trials were carried out in the 2015/16 and 2016/17 crop seasons, with a complete block design, with three replications. Thirty S3 maize inbred lines were evaluated in crosses with the AG8025, P30B39, MLP102, 60.H23.1 and 70.H26.1 testers forming 150 hybrids topcrosses. The trait evaluated was grain yield. The adaptability and stability of testers and inbred lines were evaluated by the methodology of analysis of main additive effects and multiplicative interaction directed to the interaction of testers x inbred lines. The 96.3 inbred line has the most homogeneous performance and the highest grain yield, considering the crossing with all testers in both environments. The 70.H26.1 tester is considered the most stable and the most recommended for topcrosses. The best specific combinations were 96.3 x 70.H26.1 and 96.3 x 60.H23.1.

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. Organic agriculture systems have the nutrients supplied by plant or animal by-products, bioinoculants, and compost-based products as earthworm composts and green manures. However, the quantitative and qualitative parameters of soil amendments depend on their sources, and soil amendments are generally not sufficient to supply the nutritional requirements of maize crops. Moreover, specialty maize requires high levels of N. Thus, the aim of this study was to investigate specialty maize varieties supplied with two microbial inoculants applied in two inoculation methods. These factorial treatments were compared with their checks (varieties without inoculation), and the interaction among these factors was also investigated. The trials were carried out during the growing season in 2017-2018 in the State University of Maringá. The popcorn trial followed the randomized complete block design where the factorial 3 × 2 × 2 + 3 had five replications. The trial with white grits maize followed the same experimental design but the factorial scheme was 2 × 2 × 2 + 2 with three replications. Both trials had maize varieties and two species of microbial inoculants (Azospirillum brasilense and Methylobacterium sp.) applied in two inoculation methods, in the seeds and the foliar spray at V4 stage of plant development. The response traits were grain yield and the components of crop production. In both trials, we verified that the majority of the interactions among the factors was non-significant (p > 0.05), indicating the independence of these factors. Furthermore, the microbial inoculants had no beneficial effects on the traits. The possibility of a higher crop yield did not confirm the application of the inoculant in the stage V4. The organic compost may be the key point in mitigating the treatments with microbial inoculants due to the availability of N in the first stages of plant development. The traits also suggest the necessity of more trials about the influence of microbial inoculants on specialty maize production.

ABSTRACT The aims of this study were: to assess the genetic relationship of supersweet corn populations; and to establish the heterotic pattern of 49 supersweet (sh2) corn inbreds on F2S5 generation based on molecular marker data and specific combining ability. Forty-nine inbreds were evaluated using 20 SSR molecular markers, which were allocated into heterotic groups according to the discriminant principal component analysis. Twelve inbreds were crossed in a complete diallel scheme. The 81 entries (hybrids developed, parental lines and three commercial checks) were evaluated in a triple partial balanced lattice design (9 × 9) during the growing seasons of 2016/2017 and 2017. The general combining ability (GCA) and specific combining ability (SCA) were estimated. The SCA values were used to set the heterotic patterns of the parental lines as well. Commercial yield without husk (CYWH) and ear length (EL) were more informative to set the heterotic groups. Additive and non-additive effects were important on the genetic control of the evaluated traits. However, for five of the six traits, the non-additive/dominance genetic effects showed to be more important in both environments. In fact, the hybrids developed among tropical by temperate germplasm had better performance than those ones developed within the temperate germplasm itself. SSR based-genetic distance demonstrate to be a reliable predictor as significant correlation was obtained between genetic distance with hybrid performance (for length of ears, ear height and CYWH) and SCA for all observed traits. The non-additive genetic effect that predominantly controlled all traits was the feasible explanation for the good prediction.

ABSTRACT Ear rot caused by fungi of genus Fusarium (FER) is one of the potentially harmful diseases to grain quality in maize. Given the capacity to produce mycotoxins, FER presents a risk to food safety. This study sought to identify parents and indicate hybrids of popcorn with a higher level of resistance to the incidence and severity of FER. Hybrids were produced from the crossing of 15 lines in S7 generation and 5 testers. The hybrids, together with the parents and five more genotypes used as control, were evaluated in a field trial. It was used a randomized block design arranged in 10 x 10 lattice. Data were submitted to analysis of variance by the F test (p < 0.05) and then by the mean grouping test of Scott Knott (p < 0.05). The results showed the possible to explore new sources of resistance to FER among germplasm evaluated. Both additive and non-additive gene effects are important in FER resistance. To obtain gains in FER resistance, the development of popcorn hybrids should consider the use of parental lines with low means of severity and good general combining ability.

Abstract: The seedling traits is a simple and non-destructive methodology used to identify haploids/diploids in maize. This study aimed at establishing an optimal germination temperature to evaluate this methodology and verify its effectiveness. Haploid and diploid seeds, obtained from crosses with the haploidy inducer TAIL9, were classified using the R1-Navajo marker and placed to germinated in growth chambers maintained at different temperatures. After 96 h, radicle and coleoptile lengths and the number of lateral seminal roots were determined. Cut-off points for these traits were established using Receiver Operating Characteristic curves and a new haploid/diploid classification was performed and compared to the plant phenotype (gold standard) to obtain false discovery rates and false negative rates. The seedling traits methodology successfully differentiated haploids and diploids, proving to be effective in eliminating false positives, selected by the R1-Navajo marker. The temperature of 30 °C was established as the optimal germination temperature for this study.

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.

Resumo: Apesar do teste de envelhecimento acelerado ser um dos mais empregados na avaliação da qualidade fisiológica de sementes de soja, são escassos os trabalhos que o relacionam com outros testes fisiológicos empregados na cultura. Neste contexto, o objetivo neste trabalho foi investigar as relações do envelhecimento acelerado com os resultados de desempenho fisiológico obtido nos testes de vigor mais frequentemente utilizados no sistema de controle de qualidade de sementes de soja (germinação, primeira contagem da germinação, classificação do vigor da plântula, envelhecimento acelerado, condutividade elétrica, índice de velocidade de emergência, emergência final em substrato de areia e emergência em campo). O experimento foi conduzido com sementes apresentando distintos níveis de vigor, adotando-se o delineamento experimental inteiramente casualizado, com quatro repetições. Os dados obtidos foram submetidos à análise de correlação simples de Pearson (r) e análise de regressão linear simples a 1% e 5% de probabilidade. Os resultados demonstraram que o teste de classificação do vigor da plântula (r = 0,9160) e de emergência em campo (r = 0,9198) foram aqueles que se correlacionaram em maior grau com o envelhecimento acelerado, seguidos pela germinação (r = 0,8690), primeira contagem de germinação (r = 0,8460) e condutividade elétrica (r = 0,8912).

Abstract: Although accelerated aging is one of the tests most used for evaluation of the physiological quality of soybean seeds, there are few studies that relate it to other physiological tests used for the crop. In this context, the objective of this study was to investigate the relationship of accelerated aging to the results of physiological performance obtained in the vigor tests most frequently used in the soybean quality control system (germination, first count, seedling vigor classification, accelerated aging, electrical conductivity, emergence speed index, final emergence in sand substrate, and field emergence). The experiment was conducted with seeds that had different vigor levels, adopting a completely randomized experimental design with four replications. Pearson simple correlation analysis (r) and simple linear regression analysis at both 1% and 5% probability were conducted on the data. The results showed that the seedling vigor classification test (r = 0.9160) and the field emergence test (r = 0.9198) were those that best correlated with accelerated aging, followed by the germination (r = 0.8690), first count of germination (r = 0.8460), and electrical conductivity (r = 0.8912) tests.

ABSTRACT Maize is one of the species with greater genetic diversity among cereals and possibly the most diverse crop species known. Accessing this variability is essential for maize breeding, allowing breeders to achieve progress of yield increasing, overcome environmental challenges or deal with pests and diseases. Among the maize diseases, southern rust is one of the most important, causing significant losses in yield and presenting severe epidemics worldwide. In the present study, the AFLP technique was applied to analyze population structure and genetic diversity among 145 tropical maize inbred lines, and to test for preliminary evidence of association between AFLP markers and the reaction to southern rust. Disease severity was evaluated in two crop seasons and the accessions were genotyped through AFLP using four primer combinations. The clusters obtained based on the Jaccard genetic distance and Ward’s hierarchical clustering and those achieved by structure simulations had high concordance and were capable of establish two big clusters, one predominantly of common maize and another of popcorn. The association analysis was performed using four different statistical models. The more complete model containing both population structure and genetic relatedness narrowed the number of significant associations, demonstrating its importance to control false associations. A total of 19 significant marker associations were identified from which three (EactMctg18, EactMctg205, EactMctg169) are interesting candidates for further investigations.

ABSTRACT In the present study it is hypothesized that the germplasm of popcorn of tropical regions shows resistance to FAW, and the multivariate analysis can characterize the main traits of this resistance. Thus, the aim of this study was to identify key traits used to select fall armyworm resistance in popcorn by using factor and cluster analyses. Sixteen biological traits were evaluated at larval and pupae stages: total number of armyworm, time larval period, final mass of caterpillars, total mass of caterpillars, mean mass of caterpillars, pupae period, mass of pupae and some indices used to evaluate the food consumed by the caterpillars. Multicollinearity diagnosis, factor and canonical analysis, and the genetic divergence among the genotypes were performed to implement multivariate analysis. The groups were established according to Mojena (1977). After multicollinearity test, only five traits were retained for further analysis. The factor analysis divided the five traits into two factors: the first factor included time larval period, metabolized food and mass of pupae; the second was composed of total number of armyworm and stool mass. Unweighted Pair Group Method with Arithmetic Mean (UPGMA) grouped the eighteen genotypes in three clusters. The present study provides insights of popcorn resistance to fall armyworm, and the multivariate analytical approach used here is directly applicable to any species and set of traits exhibiting correlation.