Abstract The hybrids UENF N01, N02 and N03 have enhanced nitrogen-use efficiency, particularly in terms of N responsiveness, which makes them ideal for low-input cultivation. Even under abiotic stress, popping expansion is not reduced, indicating these hybrids for growth in the N and NW of Rio de Janeiro State. N01 N0 nitrogenuse nitrogen use efficiency responsiveness lowinput low input cultivation stress reduced State

Abstract The hybrids are responsive to phosphorus application, have high use efficiency and can produce high mean yields in environments with low and high phosphorus. The mean PE of these hybrids is high, therefore they are recommended for cultivation in the North and Northwest regions of Rio de Janeiro State, Brazil. application State Brazil

ABSTRACT Brazil is one of the world’s largest producers of guava (Psidium guajava L.), a very promising fruit in the northern region of the state of Rio de Janeiro. Despite this, no guava cultivar has been developed for the region. Thus, this study proposed to examine a population of guava full sibs using microsatellite markers and to identify which genotypes are the most divergent for future crosses, to select cultivars better adapted to the soil and climatic conditions of northern Rio Janeiro. Ninety-six superior genotypes were selected according to their agronomic traits, which were characterized using 45 microsatellite markers. The genetic distance between the analyzed genotypes, their clustering pattern and the genetic structure of the population were estimated. Hierarchical cluster analysis by the neighbor joining method indicated the formation of three distinct groups. The use of molecular information revealed the existence of moderate genetic variability between the genotypes of the full-sib families. Bayesian analysis separated the genotypes into only two groups, as the individuals shared most of the analyzed genomic regions. The most genetically divergent guava genotypes, that is, those allocated to different groups, such as genotypes 5 and 85, should be recommended for future crosses to obtain segregating populations, thus giving continuity to the guava breeding program.

ABSTRACT: The purpose of this study was to conduct selection, genetic parameter estimation, and prediction of genetic values for 18 S1 families of guava trees using mixed model methodology and simultaneous selection of traits by means of the additive selection index, multiplicative selection index, and mean rank adapted from Mulamba. All families analyzed were obtained by means of self-fertilization of superior genotypes (full siblings) from the genetic breeding program of guava trees at the Universidade Estadual do Norte Fluminense. An experimental randomized block design with 18 S1 families, three replicates, and ten plants per plot was used. A total of 540 genotypes (individual plants) of guava tree were evaluated. Genetic parameter estimation and selection of the best genotypes based on the genetic value were performed using the statistical procedure, from the Selegen-REML/BLUP program. The analyses of the additive selection index, multiplicative selection index, and the sum of rank adapted from Mulamba were also performed under the Selegen program. During the evaluation by the individual BLUPs, families 1, 12, 4, 6, and 8 contributed to most of the genotypes selected for the traits under evaluation, suggesting their significant potential to generate high quality and high yield genotypes. In the selection indexes via mixed models, the multiplicative index showed higher values for genetic gains (74 %), followed by the mean rank index adapted from Mulamba (19 %), and the additive index (2 %).

Abstract The major hindrance to guava fruit (Psidium guajava L.) growing is the low availability of cultivars for use by Brazilian producers, who usually rely on few options of genotypes to implement the crop. In the present study, 11 full-sib families were evaluated in a randomized-block experimental design with three replicates, in order to more efficiently select superior genotypes. Genetic parameters were estimated and the best genotypes were selected based on genetic value by applying the REML/BLUP statistical procedure. Additionally, genetic divergence was estimated based on the mean Euclidian distance between the individuals selected via BLUP. Based on genetic divergence, the best genotypes were selected for use as parents in new crosses aiming at continuity of the guava breeding program. The mean values of the traits of selected individuals surpassed the mean values of their parents, confirming that the strategy of obtaining full-sib families is effective in generating considerable gains.

ABSTRACT. Since 2001, the disease known as 'guava decline', resulting from the interaction between the phytonematode Meloidogyne enterolobii and the fungus Fusarium solanie, has caused direct and indirect economic losses to the entire guava production chain. Given the lack of sources of resistance in guava genotypes, interspecific hybrids of Psidium spp. were obtained for resistance to the nematode M. enterolobii. To classify the level of resistance of the interspecific hybrids, we evaluated the plant classification methodologies proposed by Oostenbrink (1966) and Moura and Régis (1987). Estimates of genetic parameters were obtained using the REML/BLUP approach. Interspecific hybrids resistant to M. enterolobii were selected that can be used as rootstocks or in new crosses for the development of the guava breeding program.

ABSTRACT Compared with the common corn, popcorn shows greater susceptibility to pests and diseases occurrence, being the use of resistant cultivars the most efficient strategy. In this regard, Germplasm Banks deserve special attention because they contain accessions that can be used as sources of resistance in breeding programs. The State University of Northern Rio de Janeiro (UENF) maintains a popcorn Germplasm Bank with accessions from tropical and temperate countries, including Diversity Centers for the species. In this study, we investigated the performance of 37 popcorn accessions landraces, hybrids, and inbreed lines ― from the Germplasm Collection of UENF’s Popcorn Breeding Program with respect to the fungal leaf diseases northern leaf blight (NLB) and southern leaf blight (SLB), caused by Exserohilum turcicum and Bipolaris maydis, aiming to select promising accessions for genetic resistance to be used in future crosses to generate new resistant cultivars for farmers. The dendrogram scattering by the UPGMA multivariate technique was efficient in discriminating resistant accessions. Satisfactory results were obtained for resistance to NLB in accessions L71, L75, L76, P7, and PARA-172, which can thus be considered remarkable sources of resistance. For resistance to SLB, the superior accessions that can be indicated as sources of resistance are ARZM-05083, ARZM-07049, and PARA-172.

Resumo O presente trabalho teve como objetivo identificar os efeitos diretos e indiretos de caracteres de produção de frutos de maracujazeiro-azedo sobre caracteres de interesse agronômico, assim como verificar as possíveis mudanças de associações entre os caracteres após a realização de três ciclos de seleção recorrente. Vinte e três progênies de meios-irmãos foram avaliadas para as características número de frutos por planta, massa de frutos por planta (g), porcentagem de polpa (%), comprimento e diâmetro de frutos (mm), espessura da casca (mm), teor de sólidos solúveis totais (°brix), pH e produtividade por planta (kg). A característica produção de frutos por planta foi considerada a variável principal, e as demais características variáveis, explicativas. A herdabilidade dentro das famílias (h2ad) apresentou valores inferiores comparados à herdabilidade média da progênie (h2mp). Pela análise de trilha, observou-se que a seleção direta de genótipos com maior número de frutos ou massa média de frutos acarreta aumento na produção por planta; no entanto, a seleção indireta é ineficiente em promover ganhos simultâneos. Assim, pela verificação das correlações ao longo dos ciclos de seleção, pode-se afirmar que, apesar de a variável produção por planta ser a mais importante, deve-se dar preferência para o uso dos índices de seleção, visto que há melhores possibilidades de obtenção de ganho para características de qualidade e produção de frutos na seleção entre as progênies de meios-irmãos de maracujazeiro-azedo.

Abstract The present study was developed to identify the direct and indirect effects of fruit production traits in passion fruit on traits of agronomic interest as well as determine possible changes in associations between the characters after three cycles of recurrent selection. Twenty three half-sibling progenies were evaluated for the characteristics number of fruits per plant; fruit mass per plant (g); pulp percentage (%); fruit length and diameter (mm); peel thickness (mm); total soluble solids content (ºBrix); pH; and yield per plant (kg). Fruit production per plant was considered the main variable, while the others were considered explanatory variables. Within-family heritability (h2ad) values were lower than the mean heritability of the progeny (h2mp). Path analysis revealed that the direct selection of genotypes with higher number of fruits or fruit average mass results in increased production per plant; however, indirect selection is inefficient in providing simultaneous gains. Therefore, by observing the correlations throughout selection cycles, it can be stated that although production per plant is the most important variable, preference should be given to the use of selection indices, as there are better chances of obtaining gains for fruit quality and production traits in selection across half-sibling passion fruit progenies.

RESUMO. Com o objetivo de investigar a resistência a Exserohilum turcicum na população de milho-pipoca UENF-14, bem como inclusão desta característica na análise, duzentas e dez famílias de meios-irmãos foram avaliados usando delineamento em blocos incompletos, com tratamentos dispostos em repetições dentro "Sets". Em relação à fonte de variação Famílias dentro "Set" (F / S), foi encontrada variabilidade genética suficiente para ser explorada nos próximos ciclos do programa de melhoramento de milho-pipoca da UENF em relação à doença helmintosporiose. A variedade de polinização aberta UENF-14 tem na sua base genética fonte de resistência à doença, devido ao fato que a mesma se originou a partir de cruzamento com a cultivar de grãos amarelos Americana, que é resistente à doença. Tais resultados vêm reforçar a possibilidade de seleção de famílias resistentes através dos ciclos. Portanto, concluiu-se que a seleção foi eficaz em manter o equilíbrio da doença na população em estudo e que a fonte de resistência não é perdida com o avanço dos ciclos de seleção. A adição da variável doença foliar na análise é de extrema importância para o melhoramento do milho-pipoca, pois torna possível agregar os genes para resistência a esta doença juntamente com as características agronômicas de interesse.

ABSTRACT . To investigate the genetic resistance to northern corn leaf blight (Exserohilum turcicum) disease in the UENF-14 popcorn population and the inclusion of this trait in the analysis, two hundred ten popcorn half-sib families were evaluated using an incomplete block design with treatments arranged in replicates "Sets". Regarding the Families within "Set" (F/S) source of variation, enough genetic variability was found for northern corn leaf blight disease resistance to be explored in the next cycles of the UENF popcorn breeding program. The open-pollinated UENF-14 variety has a source of resistance to this disease in its genetic basis, given that it originated from crossing with an American cultivar with yellow grains that is resistant to disease. These results strengthen the possibility of selecting resistant families across the cycles, so it is concluded that the selection was effective at maintaining the balance in the occurrence of the disease in the study population and that the source of resistance is not lost with advancing cycles. The addition of the foliar disease variable in the analysis is of the utmost importance for the improvement of popcorn as it makes it possible to aggregate genes for resistance to this disease along with agronomic traits of interest.

Abstract This study aimed to evaluate the effect of recurrent selection on the genetic variability of UENF-14 population after six selections. Two hundred and ten half-sib families were evaluated in two environments in the state of Rio de Janeiro, using incomplete randomized blocks design with treatments arranged in replication within "Sets". There was significant effect for Families within the "Set" (F)/S, proving that there is enough genetic variability to be exploited in the popcorn breeding program of UENF. The significance for the source of variation Environment (E) shows that the environments were distinct enough to promote differences between the evaluated characteristics. It was found that for both characteristics of greatest interest, GY and PE, the magnitude of the additive variance remains with close values in advanced cycles of UENF-14 population, indicating that variability remains, with no evidence of decreases in advanced cycles. This is concluded by the longevity of UENF breeding program.

RESUMO O uso de topcross vem se mostrando uma opção interessante para a cultura do milho; entretanto, para o milho-pipoca, há pouca informação sobre a escolha do testador adequado. Nesse contexto, este estudo teve como objetivo analisar quatro testadores, sendo duas variedades de polinização aberta (BRS Angela e UENF-14), um híbrido topcross (IAC 125) e uma linhagem (P2), visando avaliar a capacidade combinatória de 50 famílias S3 de milho-pipoca, obtidas a partir da variedade UENF-14. Avaliou-se o rendimento de grãos (RG) e capacidade de expansão (CE). Obtiveram-se as estimativas das capacidades geral e específica de combinação, bem como efetuou-se a discriminação de cada testador por meio de índice de diferenciação. Os testadores BRS Angela (para RG) e IAC 125 (para CE) foram os que se destacaram, quando combinados com as melhores famílias S3derivadas da variedade UENF-14, para produção de híbridos de milho-pipoca para as Regiões Norte e Noroeste Fluminense.

ABSTRACT The use of topcross has proven to be an interesting option for the maize crop; however, for the popcorn, there is little information about the choice of the appropriate tester. In this context, this study aimed to analyze four testers including two open pollinated varieties(BRS Angela and UENF-14), one topcross hybrid (IAC125) and a line (P2), to evaluate the combining ability of 50 S3 families of popcorn, obtained from the UENF-14 variety. Popcorn families were evaluated for grain yield (GY) and popping expansion (PE). The estimates of general and specific combining abilities were obtained and the discrimination of each tester through differentiation index was carried out. The testers BRS Angela (for GY) and IAC 125 (for PE) were the most adequate, when combined with the best S3 families derived from UENF-14, for the production of popcorn hybrids for the Northern and Northwestern Fluminense Regions.

RESUMO O conhecimento do sentido e do grau de associação entre duas ou mais características pode contribuir para aumentar a eficiência na seleção de genótipos superiores. Objetivou-se com esse trabalho avaliar as correlações fenotípicas, genotípicas e ambientais, bem como os efeitos diretos e indiretos da análise de trilha para a seleção mais apropriada, via capacidade de expansão e seus componentes primários e secundários, em híbridos dialélicos de milho-pipoca. Para tanto, 90 híbridos dialélicos e a testemunha (IAC 112) foram semeados em safra e safrinha em Campos dos Goytacazes - RJ, de acordo com o delineamento em blocos casualizados. As características avaliadas foram: ciclo (CO); altura da planta (AP); altura da espiga (AE); diâmetro do colmo (DC); massa de cem grãos (M100); capacidade de expansão do grão (CE); produtividade de grãos (PG); prolificidade (PR); comprimento do grão (CG), largura do grão (LG) e espessura do grão (EG). Procederam-se as análises de correlação fenotípica (rf), genotípica (rg) e ambiental (ra) e após, realizou-se o desdobramento dos coeficientes de correlação simples em efeitos diretos e indiretos sobre a variável principal CE, obtidos pela análise de trilha. Os resultados demonstraram uma alta correlação genotípica negativa e significativa entre CE e PG de -0,67, evidenciando a dificuldade de obtenção de híbridos com alta CE e PG, simultaneamente. A M100 e a PG são as variáveis com maior associação, porém contrária, com capacidade de expansão. O CG e LG têm influência direta negativa e EG positiva sobre a capacidade de expansão.

ABSTRACT Knowledge of the direction and degree of association between two or more characteristics may contribute to increase efficiency in the selection of superior genotypes. The aim of this study was to evaluate phenotypic, genotypic and environmental correlations, as well as the direct and indirect effects of path analysis, for the most suitable selection, using expansion capacity and its primary and secondary components, in diallel hybrids of popcorn. Accordingly, 90 diallel hybrids and a control (IAC 112) were planted both in and out of season in Campos dos Goytacazes, in the State of Rio de Janeiro, following a randomised block design. The characteristics under evaluation were: cycle (CO); plant height (AP); ear height (AE); stem diameter (DC); hundred grain weight (M100); grain expansion capacity (CE); Grain yield (PG); prolificacy (PR); grain length (CG), grain width (LG) and grain thickness (EG). Analysis of the phenotypic (rf), genotypic (rg) and environmental (ra) correlations were carried out, followed by breakdown of the simple correlation coefficients obtained from path analysis into their direct and indirect effects on the main variable CE. The results showed a significant high negative genotypic correlation between the EC and PG of -0.67, demonstrating the difficulty of obtaining hybrids with both a high EC and PG. The variables M100 and PG have the greatest association with expansion capacity, albeit negative. Both the CG and LG have a direct negative influence, and the EG, a direct positive influence, on expansion capacity.

O presente trabalho tem como objetivo informar a comunidade científica os aspectos relacionados à cultivar de milho-pipoca UENF 14, desenvolvida a partir de cinco ciclos de seleção recorrente da população UNB-2U. A cultivar obteve produtividade de 3047.58 kg ha-1 e capacidade de expansão de 35.69 mL g-1.

The aim of this work is to present the features of the popcorn cultivar UENF 14, developed from five cycles of recurrent selection of the population UNB-2U, to the scientific community. The cultivar produces yields of 3047.58 kg ha-1 and has popping expansion of 35.69 mL g-1.

O presente trabalho teve com objetivo averiguar as parametrizações heteróticas de cruzamentos dialélicos entre dez linhagens de milho pipoca oriundas de genótipos tropicais, temperados e semi-temperados, em dois ambientes (municípios de Campos dos Goytacazes e Itaocara, Estado do Rio de Janeiro), em relação às características rendimento de grãos; altura média de planta e da inserção da primeira espiga; número médio de dias para florescimento e capacidade expansão. As linhagens e os híbridos foram avaliados em delineamento em blocos ao acaso, com três repetições. Para as fontes de variação linhagens e heterose houve significância, pelo teste F, para todas as características. No desdobramento da fonte de variação heterose, estimativas de heterose média foram significativas para todas as características. Em relação à heterose de linhagens e específica, apenas a característica capacidade de expansão não expressou diferença significativa, o que confirma que os efeitos heteróticos não são favoráveis para síntese de híbridos com superioridade. A relação direta entre g i e Vi ficou claro, especialmente para as características pouco influenciadas pelos efeitos de dominância. O efeito gênico aditivo foi confirmado para capacidade de expansão. As combinações híbridas revelaram estimativas positivas de heterose para GY, mas não para PE. Os híbridos P1 x P2 e P3 x P4 tiveram as melhores respostas para GY e PE. A superioridade da combinação P1 x P3, demonstra que a adição de genomas com adaptação edafoclimáticas diferentes é importante para a obtenção de híbridos superiores.

We examined the heterotic parameterizations of diallel crosses among 10 popcorn inbred lines in two different environments (municipalities of Campos dos Goytacazes and Itaocara, Rio de Janeiro State) and originating from tropical, temperate and subtropical germoplasm. Traits, including grain yield (GY), plant height (PH), ear height (EH), days to silking (FL) and popping expansion (PE), were measured. The inbred lines and the hybrids were evaluated in a randomized complete block design with three replications. The sources of genotypic variation, inbred lines and heterosis had significant effects on all traits. When the sources of heterotic variation were compared separately, estimated mean heterosis was found to be significant for all traits. When inbred lines and specific heterosis was investigated, only popping expansion was not significantly different, demonstrating that heterotic effects are favorable for developing superior hybrids. A direct relation between g i and Vi was made clear, especially for traits that were slightly influenced by the effects of dominance. Additivity was determined to have the best effect for improving popping expansion. The hybrid combinations had positive estimates of heterosis for the GY but not for PE. The hybrids P1 x P3 and P2 x P4 had the best responses for the GY and PE. The superiority of the combination P1 x P3 shows that the addition of genomes with different edaphoclimatic adaptations is an important factor in obtaining superior hybrids.