perennial breeding species demand substantial investment in various resources, mainly the required time to obtain adult and productive plants. estimating several genetic parameters in these species, in a more confidence way, means saving resources when selecting a new genotype. A model using the Bayesian approach was compared with the frequentist methodology for selecting superior genotypes. A population of 17 families of full-siblings of guava tree was evaluated, and the yield, fruit mass, and pulp mass were measured. The Bayesian methodology suggest more accurate estimates of variance components, as well as better results to fit of model in a cross-validation. Proper priori for Bayesian model is very important to convergency of chains, mainly for small datasets. Even with poor priori, Bayesian was better than frequentist approach.

Green manure brings numerous benefits that promote, essentially, the maintenance and conservation of agro-systems and its implementation is fundamental to Brazilian Cerrado region. In this scenario, the present research aimed to determine the sample size for estimation biomass and productivity of sunn and showy rattlebox. The experiment was installed in the experimental area of the State University of Mato Grosso do Sul-Unit University Aquidauana (UEMS/UUA), located in the Brazilian Cerrado. It were randomly selected 45 plants in the experimental area of each crop to determine Fresh Mass (FM), Dry Mass (DM) and yield (YI), being the measures of central tendency, variability, asymmetry and kurtosis were calculated and checked for normality by Lilliefors's test. In sunn and showy rattlebox, 340 and 197 plants, respectively, are sufficient for the estimation of evaluated descriptors, with confidence interval of 95%. The species evaluated did not differ for the characters FM and DM, both of which are recommended for cultivation in the Cerrado.

Combining the use of agronomic, disease-resistance, and molecular information can 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, one interspecific 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, estimate diversity 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.

The purpose of this study was to conduct selection, genetic parameter estimation, and prediction of genetic values for 18 S 1 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 S 1 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 %).

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Markers are an important tool in plant breeding, which can improve conventional phenotypic breeding, generating more accurate information outcoming better decision making. This study aimed to apply and compare the fit of different Bayesian models BRR, BayesA, BayesB, BayesB (setting the value from very low to $$\pi$$ π = $${10}^{-5}$$ 10 - 5 ), BayesC and Bayesian Lasso (LASSO) for predictions of the genomic genetic values of productivity and quality traits of a guava population. The models were fitted for traits fruit mass, pulp mass, soluble solids content, fruit number, and production per plant in the genomic prediction with SSR markers, obtained through the CTAB extraction method with 200 primers. The Bayesian ridge regression model showed the best results for all traits and was chosen to predict the individual’s genomic values according to the cross-validation data. A good stabilization of the Markov and Monte Carlo chains was observed with the mean values close to the observed phenotypic means. Heritabilities showed good predictive accuracy. The model showed strong correlations between some traits, allowing indirect selection.

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 study of the genetic control of agronomic traits and heritage through estimates of genetic parameters of a population allows inferences about its genetic variability and which can be expected of gain with selection. Know the correlations among traits of interest for selection allows to the breeder know the degree of association among traits of economic importance, given that the selection of certain trait changes the behavior of the other. With the aim to estimate genetic parameters and identify agronomic traits correlated with the grain yield of maize hybrids, an experiment was conducted at the State University of Mato Grosso do Sul -University Unit of Aquidauana (UEMS/UUA). The experimental design was a randomized block with four replications. Treatments consisted of 20 maize hybrids. The traits evaluated were: plant height, first ear height, stem diameter, ear diameter, ear length, number of rows per ear, number of kernels per row, hundred grain weight and grain yield. The hybrids XB9010, P30F53, 20A78HX, XB6012, P3340, AG9010 and XB7253, obtained the highest grain yield and mass of one hundred grains. The population has a genetic variability and potential for selection of all traits. Based on the evaluated genetic parameters, mass of hundred grains can be used at the direct selection of genotypes with high grain yield.