Abstract The objective of this work was to estimate the genetic parameters and to evaluate the genotypic diversity of 12 'Tahiti' acid lime (Citrus latifolia) genotypes grafted onto two rootstocks. The experiment was carried out from July 2017 to January 2019, in the municipality of São Mateus, in the state of Espírito Santo, Brazil. Vegetative (stem diameter, canopy projection diameter, and plant height), productive (yield and fruit number), and fruit quality (fruit diameter, soluble solids content, and juice yield) traits were determined. A mixed model was used to estimate heritability and repeatability coefficients, as well as to predict clonal values. Scion diversity was determined through the standardized mean difference of Euclidean distances, and genotypes were clustered by modified Tocher. Clustering quality and trait importance were evaluated using the principal component analysis (PCA). Genotypic variance was observed, which is indicative of the possibility of selection of superior genotypes. The Tocher method showed the presence of three clusters, which is in alignment with the PCA results. The multivariate analyses allows of the selection and the recommendation of superior 'Tahiti' acid lime genotypes.

Resumo O objetivo deste trabalho foi estimar os parâmetros genéticos e avaliar a diversidade genética de 12 genótipos de lima ácida 'Tahiti' (Citrus latifolia) enxertados em dois porta-enxertos. O experimento foi conduzido de julho de 2017 a janeiro de 2019, no município de São Mateus, no estado de Espírito Santo, Brasil. Foram mensuradas características vegetativas (diâmetro de caule, diâmetro de projeção de copa e altura de planta), produtivas (rendimento e número de frutos) e de qualidade de frutos (diâmetros de fruto, teor de sólidos solúveis e rendimento de suco). Utilizou-se modelo misto para estimar os coeficientes de herdabilidade e repetibilidade, bem como predizer os valores genéticos. A diversidade entre os enxertos foi obtida por meio da diferença da distância euclidiana média padronizada, e os genótipos foram agrupados pelo método de Tocher modificado. A qualidade do agrupamento e a importância dos caracteres foi avaliada pela análise de componentes principais (ACP). Observou-se variabilidade genética, o que indica a possibilidade de seleção de genótipos superiores. O método de Tocher mostrou a presença de três grupos de genótipos, o que foi congruente com os resultados da ACP. O uso de técnicas multivariadas permite a seleção e a recomendação de genótipos superiores de lima ácida 'Tahiti'.

RESUMO: Embora a produtividade seja uma característica fundamental em programas de melhoramento da lima ácida Tahiti, outras características se destacam por proporcionar uma seleção mais eficiente ou mesmo influenciar na expressão de atributos produtivos. A aplicação de inferência Bayesiana, pode tornar o processo de identificação de indivíduos superiores e o estudo das correlações entre as características ainda mais acurado. Objetivou-se, por meio deste estudo, estimar valores genéticos em genótipos de lima ácida Tahiti através de inferência Bayesiana e estimar coeficientes de correlação e de trilha entre características vegetativas, produtivas e de qualidade de frutos. Vinte e quatro genótipos de lima ácida foram avaliados durante dois anos para peso e número de frutos, volume de copa, diâmetro de caule, teor de sólidos solúveis dos frutos, espessura de casca e rendimento de suco. Os valores genéticos foram estimados por meio de inferência Bayesiana e modelos com diferentes estruturas residuais foram testados via critério de informação de deviance. Coeficiente de correlação de Pearson e de análise de trilha foram determinados, removendo o efeito de multicolinearidade. A estimação de valores genéticos via inferência Bayesiana apresentou alta acurácia seletiva. As correlações obtidas entre caracteres de diferentes grupos podem ser úteis em estratégias de seleção para melhoramento da lima ácida Tahiti. A inferência Bayesiana demonstrou ser uma ferramenta importante e deve ser considerada em programas de melhoramento de culturas perenes.

ABSTRACT: Although the fruit yield has a core importance in Tahiti acid lime breeding programs, other traits stand out among the quality fruit and vegetative traits as ones that still need to be improved in selection of superior genotypes. Appling efficient tools aiming selection, such as the Bayesian inference, becomes an alternative in perennial crops. This study applied Bayesian inference in the genetic evaluation of Tahiti acid lime genotypes and estimated the interrelation between vegetative, productive and fruit quality traits. Twenty-four acid lime genotypes were evaluated for number of fruits, fruit yield, canopy volume, stem diameter, soluble solids content, shell thickness, and juice yield traits. The genotypic values were estimated through Bayesian inference and models with different residual structure were tested via deviance information criterion. Pearson’s correlation and the path analysis were estimated, removing the multicollinearity effect. The Bayesian inference estimates genotypic values with high selective accuracy. The correlations obtained between traits from different groups can be useful in selection strategies for improvement of Tahiti acid lime. The Bayesian inference demonstrated to be an important tool and should be considered in perennial breeding programs.

RESUMO: Compreender a diversidade genética e contornar os problemas causados pela interação genótipos por ambientes é uma etapa importante em programas de melhoramento. Este estudo teve como objetivo estimar a diversidade genética e aplicar a metodologia de biplot genótipo + genótipo por ambiente (GGE biplot) em doze genótipos de algodão avaliados quanto ao rendimento da fibra, comprimento da fibra, resistência da fibra e micronaire. A estimativa dos componentes de variância e dos parâmetros genéticos foi feita através do método da máxima verossimilhança restrita e a predição dos valores genotípicos por meio da melhor predição linear não enviesada. Os métodos de Tocher modificado e análise de componentes principais (PCA) foram utilizados para quantificar a diversidade genética entre os genótipos. O método GGE biplot foi conduzido para encontrar os melhores genótipos em relação à adaptabilidade e estabilidade. As técnicas de Tocher e PCA permitiram a formação de clusters de genótipos semelhantes com base em uma estrutura multivariada. O GGE biplot indicou que os genótipos IMACV 690 e IMA08 WS foram altamente adaptáveis e estáveis para as principais características do algodão. O cruzamento dentre os genótipos IMACV 690 e IMA08 WS é o mais recomendado para aumentar o desempenho das principais características na cultura do algodão.

ABSTRACT: Understanding the genetic diversity and overcoming genotype-by-environment interaction issues is an essential step in breeding programs that aims to improve the performance of desirable traits. This study estimated genetic diversity and applied genotype + genotype-by-environment (GGE) biplot analyses in cotton genotypes. Twelve genotypes were evaluated for fiber yield, fiber length, fiber strength, and micronaire. Estimation of variance components and genetic parameters was made through restricted maximum likelihood and the prediction of genotypic values was made through best linear unbiased prediction. The modified Tocher and principal component analysis (PCA) methods, were used to quantify genetic diversity among genotypes. GGE biplot was performed to find the best genotypes regarding adaptability and stability. The Tocher technique and PCA allowed for the formation of clusters of similar genotypes based on a multivariate framework. The GGE biplot indicated that the genotypes IMACV 690 and IMA08 WS were highly adaptable and stable for the main traits in cotton. The cross between the genotype IMACV 690 and IMA08 WS is the most recommended to increase the performance of the main traits in cotton crops.

ABSTRACT Forest plantations are strong allies in preserving natural resources, providing social and economic benefits. The plantations carried out in the coming years will be vital to meet the growing demand for forest products. To ensure the continuity of genetic progress and the good results achieved with the improvement of forest species, statistical methods that accurately selects superior genotypes are desirable. Multi-trait multi-environment trials are preferred over single-trait single-environment trials, since they can exploit the covariance between traits and environments, increasing the analysis’s prediction power. The Bayesian multi-trait multi-environments approach (BMTME) combines the cited advantages with the parsimony of Bayesian statistics promoting a more informative data analysis. Thus, the aims of this study were to estimate genetic parameters, evaluate genetic variability, and select eucalyptus clones through BMTME models. To this end, a data set with 215 eucalyptus clones evaluated in four environments for diameter at breast height and Pilodyn penetration was used. The Markov Chain Monte Carlo algorithm was applied to estimate the variance components and genetic parameters and to predict the genotypic values. The Smith-Hazel index was used to simultaneously achieve gains with selection for both traits. The BMTME approach provided high accuracies, being a good strategy to the evaluation of multiple environmental trials of Eucalyptus for breeding purposes.

ABSTRACT Combining longitudinal data and statistical models from perennial crops enabled us to estimate the optimum number of measures (harvests), implying accurate discrimination of superior genotypes in those crops. Herein, the goal of this study was to determine the optimum number of harvests based on yield traits and recommend a superior graft/rootstock combination (GRC) for Citrus latifolia Tanaka. Twenty-four GRCs of 'Tahiti' acid lime were evaluated from July 2017 to August 2018 for fruit yield per plant (FYP), number of fruits per plant (NFP), and longitudinal (LFD) and transversal fruit diameter (TFD). The experimental design was a randomized complete block with 4 replications. The experimental unit consisted of three individuals, totalling 244 individuals. The GRCs were composed of (i) two hybrids that were used as rootstock, citrumelo ‘Swingle’ (Citrus paradisi x Poncirus trifoliata) and cintrandarin ‘Riverside’ (Citrus sunki x Poncirus trifoliata); and (ii) 12 different C. latifolia genotypes that were used as grafts: Bello Fruit, Eledio, Iconha, Itarana, Santa Rosa, Bearss lime, CNPMF 01, CNPMF 02, CNPMF 2001, CNPMF 5059, BRS Passos, and Persian 58. Mixed models were employed to estimate the variance components. The optimum number of harvests was determined based on selective efficiency values above 0.9. The estimated repeatability coefficients presented values of 0.14 (LFD), 0.16 (TFD), 0.36 (FYP), and 0.38 (NFD). Based on the results, four harvests were able to choose genotypes based on FYP and NFP, whereas LFD and TFD were considered inefficient traits for recommending superior GRCs.

ABSTRACT Tree breeders are prioritizing the increase of the interspecific diversity in the breeding programs due to the pronounced environmental changes, and expansion of the forest frontier to less productive areas. In this scenario, there is a growing interest for species of the genus Corymbia due to their good growth, resistance to biotic and abiotic factors, and industrial properties. Also, Corymbia spp. can cross with each other, generating interspecific hybrids. However, there are great difficulties on defining the best crosses. Thus, the objectives of this study were to evaluate the genetic variability of 64 progenies of Corymbia maculata and 64 progenies of Corymbia torelliana and to use the GGE biplot method to point the most appropriated crosses to broad and specific environments in order to generate stable and productive interspecific hybrids of C. maculata and C. torelliana. The GGE biplot was an efficient method for evaluating the genetic variability between progenies, for visualizing the genotype by environment interaction pattern and for identifying the best crosses in order to generate interspecific hybrids of the species. By adopting a selection intensity of 10%, the recommended progenies to generate interspecific hybrids for the Aracruz municipality (ARA) were 10, 40, 49, 64, 20, 9 and 47 of C. maculata and 24, 56, 41, 64, 43, 31 and 12 of C. torelliana. For Três Lagoas municipality (TLA), the recommended progenies were 11, 17, 1, 48, 7, 63 and 21 of C. maculata and 42, 46, 61, 44, 10, 63 and 28 of C. torelliana.

Resumo O Brasil representa em grande percentual a produção mundial de citros, destacando dentre várias espécies cultivadas, a limeira ácida ‘Tahiti’. No entanto, seu cultivo é sustentado por uma base genética muito estreita, sendo composto por poucas opções de copa e porta-enxerto. Deste modo, objetivou-se avaliar o desenvolvimento vegetativo e a produção de doze clones de limeira ácida ‘Tahiti’ sobre dois porta-enxertos. O experimento foi conduzido na Fazenda José Guarete, no município de São Mateus – ES. Utilizou-se o delineamento experimental de blocos ao acaso, no esquema de parcelas subdivididas, com a parcela sendo constituída por dois porta-enxertos e a subparcela, os doze clones de limeira ácida ‘Tahiti’. Foram avaliadas as características: desenvolvimento vegetativo, produção e eficiência produtiva, qualidade interna e externa dos frutos. Os clones Bello Fruit, Iconha, BRS Passos, Itarana, Persian 58, CNPMF 5059 e Elédio foram superiores nas características produtivas, vegetativas e na qualidade do fruto. O porta-enxerto citrumelo ‘Swingle’ apresentou valores referentes a características vegetativas superiores ao citrandarin ‘Riverside’. As combinações de clone e porta-enxerto que proporcionaram melhor desempenho agronômico neste estudo foram BRS Passos, Bello Fruit, Elédio e Iconha enxertadas no citrumelo ‘Swingle’ e CNPMF 5059, Iconha e Elédio sobre o citrandarin ‘Riverside’.

Abstract Brazil accounts for a large percentage of the world’s citrus production, with ‘Tahiti’ acid lime tree standing out among several cultivated species. However, its cultivation is supported by a very narrow genetic base, being composed of few scion and rootstock options. In this way, the aim of this study was to evaluate the vegetative development and production of twelve ‘Tahiti’ acid lime clones on two rootstocks. The experiment was carried out at Fazenda José Guarete, municipality of São Mateus – ES. A randomized block design was used in the split plot scheme, with plot consisting of two rootstocks and subplot of the twelve ‘Tahiti’ acid lime clones. Traits evaluated were: vegetative development, production and productive efficiency, internal and external quality of fruits. Bello Fruit, Iconha, BRS Passos, Itarana, Persian 58, CNPMF 5059 and Elédio clones were superior in terms of production, vegetative traits and fruit quality. ‘Swingle’ citrumelo rootstock showed higher values for vegetative traits compared to ‘Riverside’ citrandarin. The clone and rootstock combinations that provided better agronomic performance in this study were BRS Passos, Bello Fruit, Elédio and Iconha grafted on ‘Swingle’ citrumelo and CNPMF 5059, Iconha and Elédio grafted on ‘Riverside’ citrandarin.