Abstract This study intends to estimate the coefficient of repeatability for traits relating to yield, so as to infer what is the minimum number of evaluations required to identify superior genotypes; to verify adaptability and stability; to predict genetic gains; and to select the best families and in S1 progenies of Psidium guajava. Families were obtained by means of self-fertilization of superior genotypes (full sibs) from the guava tree genetic breeding program of the UENF. The experiment was implemented at the Experimental Station of Ilha Barra do Pomba, in the municipality of Itaocara-RJ. In this case, an experimental randomized block design was used with 18 inbred families, three replicates, and ten plants per plot. Inbred families were evaluated in three harvests regarding fruit weight, number of fruits per plant, and total yield. It was then conducted an analysis of repeatability, adaptability, and stability of genotypes by means of the Selegen/REML/BLUP program. Repeatability values show that the performance of genotypes is constant among measurements, suggesting the need to perform only three evaluations for the selection of superior genotypes. There was agreement on the choice of families 1, 4, 6, and 12 as the most yielded, adaptable, and stable for the traits evaluated.

Resumo O presente estudo tem por objetivo estimar o coeficiente de repetibilidade das características referentes à produção da goiabeira, a fim de inferir qual o número mínimo de avaliações é necessário para identificar genótipos superiores,inalém de verificar a adaptabilidade e a estabilidade, bem como prever os ganhosgenéticos e selecionar as melhores famílias em progênies S1 de Psidium guajava. Asfamílias foram obtidas por meio de autofecundações de genótipos superiores (irmãos-completos) doprograma de melhoramento genético de goiabeiras da UENF. O experimento foi implementadona Estação Experimental da Ilha Barra do Pomba, no município de Itaocara-RJ. Odelineamento experimental utilizado foi blocos ao acaso, com 18 famílias endogâmicas, três repetições e 10 plantas por parcela. Foram avaliadas as famílias endogâmicass em trêssafras, quanto ao peso dos frutos, ao número de frutos por planta e à produção total.Posteriormente, foi realizada a análise de repetibilidade, adaptabilidade e estabilidade dosgenótipos através do programa Selegem/REML-BLUP. Os valores de repetibilidade demonstram que o desempenho dos genótipos é constante entre as medições, indicando a necessidade de apenas três avaliações para a seleção dos genótipos superiores. Houve concordância naescolha das famílias 1;4; 6 e 12 como as mais produtivas, adaptáveis e estáveis para os caracteres avaliados.

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: Multicollinearity is a very common problem in studies that employ path analysis in agronomic crops, which generates unrealistic results and erroneous interpretations. This study was aimed at assessing the path analysis in data obtained from guava tree full-sib based on modelling multiple regressions applying latent variables to neutralize the effects of multicollinearity. Seven explanatory variables were measured – fruit mass (FM), fruit length (FL), fruit diameter (FD), mesocarp thickness (MT), peel thickness (PT), pulp mass (PM), total number of fruits (NTF) –, plus the main dependent variable, total yield per plant (YIELD). In accordance with the multicollinearity scenario, eleven values were tested with the addition of the constant K to the diagonal of the correlation matrix X’X. Path analysis was applied in two models: all the explanatory variables with direct effect on the dependent one and another model with multiple regression with more than one chain and the presence of latent variables. The path analysis in the multivariate methodology of structural equation modelling (SEM), which uses latent variable prediction, provided better results than the traditional and ridge path analyses.

ABSTRACT Combining the use of agronomic, disease-resistance, and molecular informationcan greatly contribute to genetic progress in breeding programs. This study was developed to estimate the genetic distance between genotypes derived from backcrosses and their parents using morphoagronomic and molecular information and information pertaining to resistance to the Cowpea aphid-borne mosaic virus (CABMV), and indicate genotypes with potential for generation advancement. The studied population consisted of 91 genotypes from the first backcross, oneinterspecific hybrid, and the species Passiflora setacea and P. edulis. For morphoagronomic characterization, the traits number of fruits, total fruit weight, average fruit weight, and area under the disease progress curve (AUDPC, related to resistance to CABMV) were evaluated. Fourteen microsatellite primers were used to estimate genetic diversity among the genotypes, estimatediversity parameters and quantify the proportion of parental genome in the evaluated genotypes. The use of morphoagronomic and molecular information revealed the existence of genetic variability among the genotypes. The mean number of alleles is close to that expected for the population. Observed heterozygosity (0.42) was higher than the expected heterozygosity (0.30), indicating an elevated number of heterozygous individuals in the population. Due to their good agronomic performance, resistance to the virus, and genotypic and phenotypic distinction, genotypes 484 and 312 are recommended to compose the future stages of the passion fruit breeding program aimed at resistance to CABMV

ABSTRACT The present study aims to characterize the genetic diversity of Passiflora setacea, P. edulis, their hybrids, and first-backcross progenies, and to indicate promising recombinants for generation advancement in a breeding program for transferring resistance to cowpea aphid-borne mosaic virus (CABMV). Ninety-one genotypes were evaluated for 37 morphoagronomic descriptors. The traits were analyzed to obtain a distance matrix, based on the Gower algorithm, using the Ward-Modified Location Model (MLM) procedure for the composition of genetic groups. The adopted strategy led to the formation of five homogeneous groups, where groups I, III, and V comprised the parents P. setacea, P. edulis and interspecific hybrids, respectively, while groups II and IV consisted of 69 genotypes of BC1. Broad variability was observed among the tested genotypes, and the highest was shown by group IV. Genotypes 17, 293, 355, and 501, from group IV, were the most promising for the second backcross cycle as they showed good resistance to the disease and desirable morphoagronomictraits.

ABSTRACT: Genetically diverse interspecific hybrids of Vitis were selected for resistance to Pratylenchus brachyurus. Three segregating populations with 57 hybrid crosses were evaluated. The parents included Vitis romanetiiC166-043 × 07355-075, 06354-047 × Cereza and 06354-047 × Nocera, selected from the germplasm bank at the University of California, Davis, the United States. The experiment was arranged in a randomized block design, with three replications and three plants per plot. Root mass, nematodes per gram of root and reproduction factor were determined and used as quantitative variables; 16 multi categoric descriptors were also evaluated. The traits were analyzed using the Ward-Modified Location Model procedure (Ward-MLM) for the composition of genotype groups. Genetic parameters and prediction of genetic values by Restricted Maximum Likelihood / Best Linear Unbiased Prediction (REML / BLUP) were assessed. The Ward-MLM classification strategy supported the formation of three homogeneous groups. Group I comprised 13 hybrids; Group II, 26 hybrids; and Group III, 18 hybrids. Groups II and III contained hybrids resistant to P. brachyurus. High broad sense heritability values were found for root mass, reproduction factor and nematodes per gram of root, which provided genetic gain and allowed selection of resistant genotypes available for cloning, since the total genetic variance occurred due to the dominance effects. Of the 57 genotypes assessed, those with the lowest genotypic values for reproduction factor were selected as resistant, including: CH3.2, CH3.23, CH3.8, CH3.37, CH3.38, CH3.41, CH3.36, CH2.1, CH2.7, CH1.1, CH1.3 and CH1.2.

ABSTRACT The aim of this study is to assess whether there is linear dependence between groups of morphoagronomic and bromatological traits in hybrid silage corn. Nineteen topcross hybrids and five checks were assessed in two different environments in Campos dos Goytacazes and Itaocara counties, Rio de Janeiro State, during the growing seasons 2013/2014. The study followed a randomized blocks design with four replicates. The phenotypic and canonical correlations between the groups of seven morphoagronomic and five bromatological traits were assessed. There is linear dependence between the group pairs of morphoagronomic, and bromatological variables. The morphoagronomic trait green mass yield can be adopted in indirect selection processes to indicate the increased bromatological quality of maize silage based on features such as crude protein, neutral detergent fiber, lignin, crude fat and mineral matter. Topcross hybrids UENF-2208 and UENF-2209 presented high potential for silage yield in the North and Northwest Regions.

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 O maracujazeiro azedo é uma importante fruteira amplamente produzida e consumida no Brasil. A produção e produtividade estão ameaçadas por vários problemas fitossanitários. Uns dos mais importantes é a fusariose, causada pelo fungo Fusarium oxysporum f. sp. passiflorae. Esta doença não tem controle eficiente. Neste sentido o objetivo deste trabalho foi avaliar a resposta de plantas, em estágio de muda, de 14 espécies de Passiflora mediante a inoculação de F. oxysporum f. sp. passiflorae cultivadas em solução nutritiva. As espécies utilizadas no Screening foram: P. quadrangularis, P. nitida, P. foetida, P. tenuifila, P. alata, P. setacea, P. cincinnata, P. mucronata, P. micropetala, P. suberosa, P. morifolia, P. eichleriana P. edulis e P. coccinea. Quatro mudas de cada genótipo foram inoculadas por imersão das raízes numa suspensão de 1x106 esporos mL-1, durante 24 horas e, em seguida, transplantada para potes contendo solução nutritiva. As plantas foram avaliadas diariamente por 40 dias para a ocorrência de sintomas de murcha e morte. Foram obtidos o período de sobrevivência e a taxa de mortalidade. O método de imersão das raízes por 24 horas e a substituição de solo por solução nutritiva foi eficiente na distinção dos genótipos resistentes. Houve variabilidade intraespecíficas em relação a doença. As espécies mais resistentes foram P. foetida. P. mucronata. P. nitida e P. morifolia.

ABSTRACT Passion fruit is an important fruit vine widely produced and consumed in Brazil. Production and productivity have been threatened by several phytosanitary problems. One of the most important problems is fusariosis, caused by the fungus Fusarium oxysporum f. sp. passiflorae. This disease has no efficient control. Thus, the aim of this study was to evaluate the response of plants of 14 Passiflora species, in the stage of seedling, through inoculation of F. oxysporum f. sp. passiflorae grown in nutritive solution. The species used in the screening were P. quadrangularis, P. nitida, P. foetida, P. tenuifila, P. alata, P. setacea, P. cincinnata, P. mucronata, P. micropetala, P. suberosa, P. morifolia P. eichleriana P. edulis and P. coccinea. Four seedlings of each genotype were inoculated by immersion of roots in a suspension of 1x106 spores mL-1 during 24 hours and then transplanted into pots containing nutritive solution. Plants were daily evaluated during 40 days for the occurrence of wilt symptoms and death. The survival period and the mortality rate were obtained. The method of root immersion for 24 hours and the replacement of soil by nutritive solution were efficient in distinguishing the resistant genotypes. There was intraspecific variability in relation to the disease. The most resistant species were P. foetida, P. mucronata, P. nitida and P. morifolia.

Resumo: O objetivo deste trabalho foi estimar os parâmetros genéticos e avaliar as associações entre características vegetativas e de produção em progênies de irmãos completos de goiabeira (Psidium guajava). Avaliaram-se as seguintes características: produção por planta, número de frutos, massa de frutos, altura da planta, diâmetro de caule e volume de copa. A estimativa de parâmetros genéticos foi obtida com o procedimento REML/Blup. Com base nos valores genéticos preditos pelo Blup, estimaram-se as correlações genéticas e canônicas, e realizou-se o desdobramento dos coeficientes de correlação genética em efeitos diretos e indiretos sobre a característica produção por planta, com análise de trilha. Estimou-se variabilidade genética para número de frutos (567,66) e produção por planta (11,818), com alta correlação genética (0,9045), o que evidencia seleção simultânea. A seleção indireta não promoveu ganhos simultâneos para produção por planta a partir dos componentes primários número de frutos e massa de frutos, o que dificulta a obtenção de cultivares de goiabeira com alta produção, número de frutos e massa de fruto. As características vegetativas apresentaram pouca influência na produção, no número de frutos e na massa de frutos.

Abstract: The objective of this work was to estimate the genetic parameters and to evaluate the associations between vegetative and yield characteristics, in full-sib progenies of guava tree (Psidium guajava). The following characteristics were evaluated: yield per plant, number of fruits, fruit mass, plant height, stem diameter, and canopy volume. The estimation of genetic parameters was obtained by the REML/Blup procedure. Based on the breeding values predicted by Blup, the genetic and canonical correlations were estimated, and the genetic correlation coefficients were unfolded into direct and indirect effects on the character yield per plant using path analysis. Genetic variability was estimated for number of fruits (567.66) and yield per plant (11.818), with high genetic correlation (0.9045), indicating simultaneous selection. Indirect selection did not promote simultaneous gains for yield per plant with the primary components number of fruits and fruit mass, making it difficult to obtain guava cultivars with high yield, number of fruits, and fruit mass. The vegetative traits had little effect on yield, number of fruits, and fruit mass.