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 One of the challenges of the energy sector is the identification of renewable resources with less impact on the environment and that are economically viable. This study aimed to estimate the genetic diversity of eleven full-sib families of elephant grass, using quantitative traits associated with bioenergy production. The trial followed a randomized blocks design, with four replications and each plot (family) consisting of five plants, totaling 220 genotypes. Five quantitative traits were measured: dry matter yield, dry matter percentage, plant height, stem diameter and number of tillers. The genetic diversity was estimated using multivariate methods (principal component analysis and hierarchical clustering). The analysis revealed a significant genetic diversity among the full-sib of elephant grass, with a greater variability observed for dry matter yield and number of tillers. The families 1, 2, 5, 7 and 8 exhibited superior genotypes for bioenergy production-related traits. The grouping analysis generated twenty clusters, enabling the differentiation of genotypes. Eight clusters comprised genotypes with a high dry matter yield and plant height, simultaneously, surpassing the overall mean for number of tillers.

RESUMO Um dos desafios do setor energético é a identificação de recursos renováveis com menor impacto ao meio ambiente e que sejam economicamente viáveis. Objetivou-se estimar a diversidade genética de onze famílias de irmãos completos de capim-elefante, utilizando-se características quantitativas associadas à produção de bioenergia. O ensaio foi conduzido em delineamento de blocos ao acaso, com quatro repetições, sendo cada parcela (família) composta por cinco plantas, totalizando 220 genótipos. Cinco características quantitativas foram mensuradas: produção de matéria seca, porcentagem de matéria seca, altura de planta, diâmetro de colmo e número de perfilhos. A estimativa da diversidade genética foi realizada por meio de métodos multivariados (componentes principais e agrupamento hierárquico). Observou-se que há diversidade genética em irmãos completos de capim-elefante, com maior amplitude de variabilidade para produção de matéria seca e número de perfilhos. As famílias 1, 2, 5, 7 e 8 apresentam genótipos superiores para características relacionadas à produção de bioenergia. Vinte grupos obtidos no agrupamento maximizaram a distinção dos genótipos. Oito grupos continham genótipos com alta produção de matéria seca e altura de planta, simultaneamente, além de valores acima da média geral para número de perfilhos.

ABSTRACT Elephant grass stands out among lignocellulosic biomass plants utilized for second-generation biofuel production due to several advantageous characteristics compared to other raw materials. Its short production cycle and ability to thrive in adverse soil and climate conditions contribute to its appeal. Additionally, breeders seek genotypes with high productivity potential and adaptability to various favorable cultivation environments. This study aimed to estimate genetic parameters, predict genetic values using mixed models (REML/BLUP), and evaluate stability and adaptability for energy biomass production in elephant grass genotypes. The experiment was conducted in Campos dos Goytacazes, RJ, Brazil, utilizing a two-replicate experimental block design that included 40 elephant grass genotypes. Four harvest assessments were performed between 2016 and 2019. Genetic parameter estimation and selection of superior genotypes based on genetic value using the REML/BLUP procedure were performed using Selegen software. Stability and adaptability analyses were obtained through the harmonic mean of genotypic values (HMGV), enabling the identification of stable and highly productive genotypes. Genotypes 17, 18, 32, 16, 36, 6, 15, 31, and 34 exhibited outstanding performance in terms of HMGV, indicating enhanced stability, adaptability, and simultaneous productivity, thus ensuring robustness in cultivation. These selected genotypes hold potential for future breeding programs aimed at improving elephant grass yield for biomass production.

ABSTRACT The elephant grass (Cenchrus purpureus (Schumach.) Morrone) is one of the species with great prominence for energy production because of its favorable traits, such as high yield and short cycle, combined with several biomass quality characteristics. Therefore, this study intended to evaluate the morpho-agronomic traits of eight elephant grass genotypes under different cutting ages. A randomized block design with three replicates was applied to the experiment, and plots were composed of a 12 m long line divided into six subplots for each of the bimonthly cuts. Eight genotypes were evaluated in the plots, and the cutting ages (2, 4, 6, 8, 10, and 12-mo) were analyzed in the subplots. The following traits were assessed: DM yield, (DMY) percentage of DM, and average plant height (HEI). All genetic-statistical analyses were conducted using the Genes Program. The evaluated genotypes showed nonsignificant differences, indicating that, for the evaluated traits, these genotypes are genetically similar. Most genotypes presented linear effect of 2nd degree in the two assessment cuts, pointing they did not reach their maximum capacity of DMY in the time interval of the evaluated cuts. The maximum %DM achieved for the most genotypes occurred at about 9-mo age, while genotypes Vruckwona and BAG-86 at about 10-mo age. The maximum points for HEI trait were between 8 and 10-mo age. Increasing the cutting interval leads to increases in DM yield, with the 10-mo cutting age being the most efficient, resulting in higher yields.

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 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 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 The REML/BLUP procedure has been successfully used for genetic progress through individual selection of high-yielding passion fruit genotypes resistant to the Cowpea aphid-borne mosaic virus. This study was thus developed to estimate genetic parameters and predict the gain obtained from individual selection of genotypes in a population derived from backcrosses in passion fruit. The experiment was set up as a randomized block design with four replicates, involving five full-sib families (genotypes from the first backcross). Variance components and the genetic values were estimated for eight agronomic traits via the REML/BLUP procedure. For all traits, genotypic variance between the genotypes from the first backcross showed little contribution to the phenotypic variance. The low heritability estimates obtained for the traits are overcome via individual BLUP estimates. Therefore, it was possible to obtain considerable gains with individual selection for the variables fruit length, average fruit weight, and pulp weight (19.50 to 14.04%; 22.93 to 17.97%; and 10.08 to 7.95%, respectively). For the traits showing lower gains, it is possible to obtain gains indirectly by selecting genotypes for correlated traits. Because this population derives from the first backcross generation, agronomic traits still must be recovered.

RESUMO O objetivo do presente trabalho foi descrever as características histológicas do processo de soldadura da enxertia e avaliar a influencia dos porta enxertos sobre as características físicas e químicas do fruto e na produtividade de populações de maracujazeiro azedo. O delineamento utilizado foi o de blocos ao acaso, num esquema fatorial 4x2+4 (cultivares/copas x porta enxertos), com três repetições e nove plantas por parcela. Foram utilizadas como copa cultivares comerciais e populações e os porta enxertos Passiflora alata e P. nitida, além do pé-franco. O tipo de enxertia foi o convencional por garfagem no topo em fenda cheia. As características analisadas como produtividade e qualidade físico química dos frutos foram submetidas à análise de variância e comparadas pelo teste de Tukey. E a morfologia da copa foi avaliada de acordo com descritores do MAPA. Foi realizada a técnica de enxertia de cada combinação enxerto/porta enxerto para a analise histológica, onde as secções foram obtidas à cortes a mão livre, coradas e montadas em lâminas semipermanente e analisadas sob microscópio óptico e fotomicrografadas. Os portas enxertos influenciaram no período inicial de cultivo reduzindo a produtividade e o número de frutos das populações de maracujazeiro, e a enxertia não influenciou na qualidade dos frutos e na morfologia da copa. Considerando o ciclo completo da cultura, a espécie P. alata possui condições de ser utilizada como porta enxerto. O estudo anatômico demonstra a ocorrência de uma melhor compatibilidade na união dos tecidos de P. edulissobre P. alata quando comparados a enxertia sobre P. nitida.

ABSTRACT The present study aimed to describe histological traits of the graft welding process and evaluate the effect of rootstocks on the physical and chemical traits and the productivity of sour passion fruit populations. The experiment was arranged in a randomized block design, in a 4x2 + 4 factorial scheme (cultivars / canopy x rootstocks), three replicates and nine plants per plot. Commercial cultivars and populations and Passiflora alata and P. nitida rootstocks, in addition to ungrafted plants were used as canopy. Cleft grafting was the grafting type adopted. Traits analyzed such as productivity and physical and chemical quality of fruits were submitted to analysis of variance and compared by the Tukey test. The canopy morphology was evaluated according to descriptors of the Ministry of Agriculture, Livestock and Supply. Grafting was carried out for each graft/rootstock combination for histological analysis. Sections were obtained by freehand cuts, stained and mounted on semi-permanent slides, examined under optical microscope and photomicrographed. Rootstocks affected the early cultivation and reduced productivity and number of fruits of passion fruit populations. Grafting did not affect the quality of fruits or the canopy morphology. Considering the complete culture cycle, P. alata species is able to be used as rootstock. The anatomical study demonstrates the occurrence of better compatibility in the connection of P. edulis tissues on P. alata, compared to grafting on P. nitida.

Resumo Este estudo visou a fornecer informações a respeito da biologia e dos recursos florais, da receptividade estigmática e da viabilidade dos grãos de pólen nas épocas de chuva e seca, e a avaliar a eficiência da polinização natural e artificial sobre a qualidade de frutos de oito cultivares de maracujazeiro-azedo, cultivadas em Tangará da Serra – MT. Foram avaliadas cinco cultivares comerciais e três populações do programa de melhoramento genético do maracujazeiro-azedo da Universidade do Estado de Mato Grosso. As condições climáticas da estação chuvosa favoreceram o maior desenvolvimento das peças florais. A concentração de açúcar no néctar apresentou médias mais elevadas na estação chuvosa, em todas as cultivares, com exceção de FB 200. As condições climáticas do período de seca favoreceram a reposição do volume de néctar. Todas as cultivares avaliadas apresentaram viabilidade polínica e receptividade estigmática superior a 79% e 90%, respectivamente. As características de massa de fruto e da porcentagem de polpa apresentaram-se melhores na polinização artificial. Os frutos obtidos de polinização natural e artificial, em todas as cultivares avaliadas, apresentam características físicas e químicas que estão dentro dos padrões de qualidade desejada na comercialização.

Abstract This study aimed to provide information on the biology and floral resources, stigmatic receptivity and viability of pollen grains during rainy season and dry season, and to evaluate the efficiency of natural and artificial pollination on quality of fruits of eight passion fruit cultivars sourced in Tangará da Serra - MT. Five commercial cultivars and three populations of the genetic improvement program of the sour passion fruit from the Universidade do Estado de Mato Grosso were evaluated. The climatic conditions of the rainy season favored the greater development of the floral pieces. The sugar concentration in the nectar presented higher averages in the rainy season, in all cultivars, except for FB 200. The climatic conditions of the dry season favored the replacement of the nectar volume. All cultivars evaluated presented pollen viability and stigmatic receptivity higher than 79% and 90%, respectively. The characteristics of fruit mass and percentage of pulp were better in artificial pollination, and the fruits obtained from natural and artificial pollination in all cultivars evaluated presented physical and chemical characteristics that are within the quality standards desired in the commercialization.