Jefferson Fernando Naves Pinto

The objective of this work was to describe and compare the patterns of genetic variation in 19 populations of Anacardium humile from the Cerrado biome of the Brazilian Midwestern region. The ex situ germplasm collection of Universidade Federal de Jataí, in the state of Goiás, Brazil, was used for the study. To quantify the genetic variability of A. humile, 529 plants from 17 populations in Goiás from 2 in the state of Mato Grosso were studied, from which nine microsatellite loci were genotyped by capillary electrophoresis. The populations showed high levels of genetic diversity, with an average value of 0.830, and high inbreeding values, which suggests a deficit of heterozygotes. The genetic differentiation value between populations was 0.065. The greatest variability, which is moderately structured, was observed within populations. There is a significant inbreeding within the A. humile population in the Cerrado biome of the Brazilian Midwestern region. The A. humile populations are divided into two groups.

Due to the strong selective pressure resulting from the misuse of antibiotics, the natural process of bacterial resistance has been accelerated, leading to the increasingly constant appearance of multiresistant isolates. The high number of multiresistant bacteria is a one health problem. Enterobacteriaceae are usually commensal bacteria of the gastrointestinal tract. However, they can cause infections, and the most important resistance characteristic among them is the production of β-lactamases. This study aimed to identify ESBL-producing Enterobacteriaceae of types of TEM, SHV, and the CTX-M groups. To isolate the enterobacteria, swabs were collected by swiping objects that had contact with the patients and professionals, and the water of the hospital environment. Ten collections were carried out, yielding 306 samples, from which 118 enterobacteria were identified: Escherichia coli, Enterobacter spp., Klebsiella spp., Proteus mirabilis, Serratia spp., and Citrobacter spp. Isolates. The genes TEM and CTX-M, for the production of β lactamases, were detected in 12.7% of the 118 enterobacterial isolates. It is very important to know the bacterial population circulating in the veterinary hospital environment and its resistance to antimicrobials so that professionals can take appropriate measures to minimize the risks of transmission, especially from cages and consultation tables. In addition, the correct control of the microbiological quality of the supply water, as well as environmental cleaning procedures, are essential to prevent the transmission of these microorganisms.

In the present study the objective was to evaluate the genetic diversity among families of maize siblings for resistance to foliar diseases associated with their agronomic potential, identifying groups of families that can be used as sources of resistance in maize crop. The experiments were conducted in the experimental area of the Federal University of Goiás at the Jataí Regional Unit, in Jataí, GO, Brazil, constituted by 182 half-sibling families of maize and two commercial hybrids as a control. The 182 half-sibling families were divided into three experiments with 60, 60 and 62 families, respectively. The experimental design used was randomized blocks, with three replicates. Eight quantitative characters and 4 foliar diseases were evaluated. The multivariate analysis technique was used to measure the genetic divergence for the four foliar diseases represented by the generalized Mahalanobis distance. Based on the genetic dissimilarity matrix, the dendrogram was constructed using the clustering method of the average distance between groups (Unweighted Pair Group Method with Arithmetic Mean - UPGMA). After defining the groups, univariate analysis of variance was performed in order to evaluate the effects of the groups on each character studied. Comparisons were made between the means of the groups, using the Tukey test (p <0.05). White spot (32.53%) was the disease that most contributed to the total divergence between families. Group 10 stood out among the others as a source of resistance to the disease complex associated with yield. The genetic variability of families for foliar disease complex reveals potential for future studies facing pyramiding genes.

Foodborne illnesses are relevant to public health, especially in contaminated foods that are eaten without prior cooking, such as lettuce. The objective was to evaluate the contamination by Shiga toxin-producing Escherichia coli (STEC), E. coli and Salmonella spp. in lettuce in commercial food-establishments in the city of Jataí, Goiás, Brazil. The variables were: type of crop, type of establishment and coliform count. The DNA of E. coli isolates were analyzed by PCR to the research of virulence genes. Isolates compatible with Salmonella in the biochemical tests were submitted for serology with Salmonella antisera. Thirty samples of lettuce were evaluated, eleven samples were positive for E. coli, (36.67%), and one sample (3.33%) tested positive for STEC hydroponic crop. The two STEC isolates were positive for the stx2 gene. Conventionally grown products were 2.4 times more likely to be contaminated with E. coli. The presence of Salmonella spp. was confirmed in 16.67% (5/30) of the samples. The presence of potentially pathogenic microorganisms in the analyzed samples indicates the need for special care to be taken in preparing fresh vegetables before they are consumed in natura, like avoid excessive handling, and washing with sanitizers.

Selecting potential progenies in early inbred generations is an essential step towards the success of breeding programs. Given this, the use of top crosses assists breeders in selecting progenies to generate lines with the potential for hybrid yield. Thus, the purpose of this study was to assess the behavior of partially inbred progenies (S1) of maize with potential for green maize yield in top crosses and to evaluate the hybrid performance. Seventy-five top cross hybrids were generated from the cross between 75 S1 progenies and the F2 generation of the hybrid AG 1051. The 75 hybrids, the male tester (F2 generation of the hybrid AG 1051 as a broad genetic base tester), and the hybrid AG 1051 were sown in a block design with four replicates. The following traits were evaluated: husked ear yield; commercial ear yield; flowering; plant height; strawing; mean weight of grain mass in green maize stage; tassel branch number; ear row number; ear length; and ear diameter. The analysis of variance was performed estimating the general combining ability, and, from the means, the Scott & Knott test was conducted. The top cross hybrids that were prominent for commercial ear yield were those composed of partially inbred progenies 19, 48, 6, 28, and 42 with high GCA, suggesting a potential for the production of open pollination population or synthetic production as well.

The objective of this work was to define the most suitable selective strategy for the simultaneous increment of yield components of green maize, by comparing three selection indexes weighted by economic weights and by the REML/BLUP method, in the assessment of predicted genetic gains for traits of interest. An experiment with 75 topcross hybrids from partially inbred S1 lines of green maize was carried out in Jataí, in the state of Goiás, Brazil, using a randomized complete block design, with four replicates. The following yield traits were evaluated: straw ears and commercial ears, grain mass, ear length, ear diameter, and number of ear rows. The selection indexes of Smith and Hazel, Williams, and Mulamba & Mock were applied and weighted for four economic weights (1, CVg, CVg/CVe, and h2). Among the tested selection indexes, those of Williams and Mulamba & Mock are the best-fit ones for the selection of topcross hybrids of green maize, as they provide positive and more balanced selection gains for all evaluated traits. The REML/BLUP method shows better predicted genetic gains than those achieved by the three selection indexes, besides being efficient for the selection of topcross hybrids of green maize.

Accessions of macaw palm fruits from the State of Goias, Brazil were characterized aiming the identification of groups with similar characteristics and indicate groups with higher agronomic potential, using multivariate tools. Fruit were harvested with completed yellow fruit bunches without whitish scores. The evaluated variables were fruit and almond length, fruit and almond diameters, fruit and dehydrated almond weight, average number of almonds, oil percentage of almond and dried fruit. The genetic diversity of populations was evaluated by Ward’s clustering method and Person´s correlation was obtained to evaluate the relative importance of each characteristic and variance analysis associated with Tukey´s test to verify the group’s effects. The studied population demonstrated great variability. The characteristics that most contributed to the variability were fruit weight and diameter and the almond´s oil percentage. Ward´s group analysis revealed six groups of similarity, being significant for all evaluated characteristics. Group VI stood out for all evaluated characteristics and group III presented the best averages for the almond´s weight and almonds and dried fruit oil percentage.

The identification of productive plants with fruits of desirable characteristics contributes to the optimization of commercial crops of red mombin fruits. The aim of this work was to evaluate the genetic diversity among the provenance of red mombin of two municipalities of the state of Goiás. The fruits were harvested at ripening stage 3 and transported to the laboratory. The treatments were composed of fruits harvested from three plants, being ten repetitions and five fruits per experimental plot, totaling fifty fruits per provenance. Considering each repetition as an individual, 15 individuals were evaluated for length, diameter, weight, color attributes of the pericarp and pulp, soluble solids content and titratable acidity of the pulp, ratio of soluble solids content and acidity, and vitamin C content of the pulp. The results were subjected to descriptive analysis. A multivariate analysis was performed estimating the mean Euclidean distance obtained from the provenances, based on the attributes of the fruits analyzed. The measure of similarity and grouping of the provenances were done through the Tocher optimization algorithm and UPGMA dendrogram. The variables contributed similarly to dissimilarity. The Tocher method grouped the individuals into four groups, while in the UPGMA dendrogram, seven groups were formed.

This study determined the distribution of stx1 and stx2 genes in Escherichia coli isolated from dairy herds with regard to animal age, season, and farm production-scale, and analyzed the phylogenetic distribution of the groups A, B1, B2, and D of 276 isolates of bovine feces Shiga toxin-producing E. coli (STEC). The stx1 profile was the most common, detected in 20.4% (202/990) of the isolates, followed by stx2 (4.54%, 45/990) and stx1+stx2 (2.92%, 29/990). The stx1 gene was detected more frequently in calves than in adult animals. In the dry season (winter), the presence of stx1+stx2 profile in cattle feces was higher than in the rainy season (summer), while no significant changes were observed between seasons for the stx1 and stx2 profiles. The most predominant phylogenetic groups in adult animals were B1, A, and D, while groups A and B1 prevailed in calves. Our data highlight the importance of identifying STEC reservoirs, since 7.5% of the tested isolates were positive for stx2, the main profile responsible for the hemolytic-uremic syndrome (HUS). Moreover, these microorganisms are adapted to survive even in hostile environments and can contaminate the food production chain, posing a significant risk to consumers of animal products.