Current issues

Table of contents: 2019

Research Article

The estimation of genetic variability in germplasm banks is important not only for the conservation of genetic resources, but also for their use in plant breeding. However, a large number of traits from different categories (qualitative and quantitative) can make the analysis and interpretation of the results difficult, often resulting in an incomplete distinction among accessions. We characterized 45 accessions of food-type soybean (Glycine max) from the Soybean Germplasm Bank of Londrina State University based on morphoagronomic traits. The experiment was carried out in the university farm using a randomized block design with three replicates. Twelve traits were evaluated: flower color, pubescence color, tegument color, hilum color, days until flowering, days until maturation, plant height, height of insertion of  the first pod, mass of 100 grains, grain yield per plot, agronomic value, and lodging index. The quantitative trait data were submitted to deviance analysis. The genetic divergence among the accessions was examined by Gower's distance and clustering of the accessions was made based on Ward's hierarchical method. Morphoagronomic descriptors proved efficient in detecting the levels of genetic variability among the accessions maintained in the germplasm collection. Gower's distance was efficient in the discrimination of accessions, showing that simultaneous analysis of quantitative and qualitative traits is useful to evaluate the variability in a germoplasm bank. These results can be used as an additional source of information to be exploited in food-type soybean breeding programs.

Genet. Mol. Res. 18(2): GMR18298
DOI: 10.4238/gmr18298
Research Article

We evaluated the association of glutathione S-transferase polymorphisms (GSTT1 and GSTM1) and oxidative stress biomarkers in patients with schizophrenia. A total of 162 subjects were studied: 53 had schizophrenia (Total Study Group-TSG), and 109 without the disorder (Total Control Group-TCG). To analyze oxidative stress, TSG was distributed into treatment-responsive schizophrenia (N = 26) and treatment-resistant (N = 27) versus control group (N = 36). Peripheral blood collection for analysis of polymorphisms, malondialdehyde (MDA) and trolox equivalent antioxidant capacity (TEAC); a questionnaire or a medical record for clinical profile and lifestyle was also applied. Frequency of genotypes did not differ significantly between the groups. The patients had a significantly reduced frequency of the combination GSTT1-null/GSTM1-present (13 versus 30%) and significantly higher plasma MDA levels, but similar TEAC values. Smoking, diabetes mellitus (DM), systemic arterial hypertension (SAH) and family history (FH) significantly prevailed in patients (TSG) compared to controls (TCG). High sensitivity and specificity values for MDA (area under the curve >0.90) were observed. Reduced frequency of the combination GSTT1-null/GSTM1-present in patients suggests exposure to oxidative stress, represented by increased MDA and mainly aggravated by smoking, SAH, DM and FH. High sensitivity and specificity identifies the potential of MDA as a marker of oxidative stress in schizophrenia.

 

Genet. Mol. Res. 18(2): GMR18259
DOI: 10.4238/gmr18259
Research Article

Marker-assisted selection has been widely used in breeding programs. The use of single nucleotide polymorphisms (SNPs) as genetic markers enables identification of genotypes that best contribute to quantitative characteristics. We evaluated a possible association between the DdeI growth hormone gene polymorphism and meat and carcass traits. A total of 476 halothane-free animals were genotyped. Animals originated from the crossing of an AGIPIC®415 male with Large White (LW) x Landrace (LD) females. Males were castrated when young and males and females were slaughtered between 150 and 180 days old. Hot carcass weight, carcass length, pH 45 min , and pH 16 postmortem of Longissimus cervicis, Longissimus dorsi, and Semimembranosus muscles, backfat thickness, Longissimus dorsi muscle depth, and color by the CIELAB system were measured and the percentage of lean meat was calculated. Water holding capacity was determined by the filter paper method in the Semimembranosus muscle. A 605-base pair (bp) amplicon was obtained by PCR and a DdeI polymorphism was genotyped and two alleles identified, D1 with 335, 148, and 122 bp and D2 allele with 457 and 148 bp. Allele frequencies were 0.43 for D1 and 0.57 for D2. Genotypic frequencies were as follows: D1D1 (22.1%), D1D2 (49.8%), and D2D2 (28.1%). The Chi-Square test showed that the population was in Hardy-Weinberg equilibrium. The results of hot carcass weight, carcass length, pH 16 postmortem of Longissimus cervicis, Longissimus dorsi, and Semimembranosus muscles, backfat thickness, Longissimus dorsi muscle depth, color and water holding capacity did not differ significantly among the genotypes. The DdeI SNP was associated with lean meat percentage and pH at 45 min posmortem in the Longissimus cervicis muscle; properties that are important for the commercialization of fresh meat as well as processed products.

 

Genet. Mol. Res. 18(2): GMR18257
DOI: 10.4238/gmr18257
Research Article

Raspberry is a berry crop of great economic importance, and its cultivation has expanded worldwide. Information on the genetic parameters of raspberry for use in breeding programs is currently limited. We used Restricted Maximum Likelihood (REML) and Best Linear Unbiased Prediction (BLUP) to estimate variance components and predict genetic parameters for morphological, phytochemical, and mineral components in primocane-fruiting raspberries in southern Brazil. The experimental design was randomized blocks in a factorial scheme, with two production cycles (fall and spring) x three cultivars (‘Alemãzinha’, ‘Heritage’ and, ‘Fallgold’), with eight replicates. A total of 27 traits were evaluated, out of which only the traits beginning of fruit harvest, plant height, dry mass of pruning, average fruit weight, total phenolic compounds, anthocyanins, antioxidant activity, Ca, Mg, Cu, Fe, Mn, Zn, and titratable acidity showed significant differences. The anthocyanins presented 87% of broad sense heritability, and this high value indicates that this trait can be improved through selection. Plant height, fruit weight, total phenolic compounds, Mg and Fe had moderate broad sense heritability (46, 58, 58, 51, and 66%, respectively); and the traits beginning of fruit harvest, dry mass of pruning, antioxidant activity, Ca, Cu, Mn, Zn, and titratable acidity are strongly influenced by production cycle effects. Greater genetic variance contribution in the interaction between genotypes × production cycle was observed for plant height, fruit weight, total phenolic compounds, anthocyanins, antioxidant activity, Mg and Fe. The genotype ‘Alemãzinha’ was superior for beginning of fruit harvest, plant height, anthocyanins, titratable acidity, and several minerals. Five inheritable profiles were found; the profile IV, including plant height, fruit weight, Mg, Fe, and total phenols had moderate broad sense heritability. Only profile V, composed of anthocianins, presented high heritability.

Genet. Mol. Res. 18(2): GMR18254
DOI: 10.4238/gmr18254
Research Article

In order to facilitate corn production, herbicides such as nicosulfuron and topramezone are commonly used. Though they offer great advantages, they can affect crop productivity and induce DNA damage. The genotoxic activity of nicosulfuron was evaluated at two concentrations (40,000 and 80,000 ppm) and topramezone at four concentrations (1480, 148, 14.8 and 1.48 ppm) respectively, in sweet corn and hybrid accessions from Mexico and South America using a comet assay system. Sweet corn apical meristematic cell nuclei were tested in 113 accessions from Mexico and South America and five commercial hybrids for nicosulfuron and nine accessions and a hybrid for topramezone. Both nicosulfuron concentrations induced significant genetic damage to sweet corn and normal hybrids. Topramezone showed significant genotoxic activity in both sweet corn and normal hybrids. Normal hybrid corn was subject to genetic damage caused by the herbicides, and all showed significant genetic damage compared to their corresponding untreated controls. Genotoxic activity of nicosulfuron and topramezone was evident; additionally, the comet assay study demonstrated that corn can be used as a biomonitor for genotoxicity assessment.

 

Genet. Mol. Res. 18(2): GMR18159
DOI: 10.4238/gmr18159
Research Article

Genetic diversity is the basis for genetic improvement as it can provide the basis for new cultivars. Stylosanthes scabra is a grasslands legume that presents potential economic importance in tropical and subtropical regions. Plants of the genus Stylosanthes naturally occur in semiarid native pastures in northeastern Brazil and are highly favored by grazing animals; therefore Brazil's Northeast stands out as an center of this genus. We evaluated the genetic diversity of S. scabra using ISSR molecular markers; naturally occurring samples were harvested from Santa Cruz do Capibaribe, Floresta, Sertânia and Petrolina in Pernambuco state, Brazil. We selected seven ISSR primers for amplification and analyzed 75 individuals, obtaining 88 bands, which amplified with 95% polymorphism at the species level. The AMOVA test revealed that 40% of the total genetic variation occurs within populations and 60% among populations. Population differentiation was 0.332 and the migrant number per generation was 0.5. Grouping analysis confirmed a high level of differentiation among populations and that the greatest variability was in Santa Cruz do Capibaribe and Petrolina regions. The ISSR markers were efficient for genetic diversity quantification in S. scabra, which presented greater variability among populations than within them. Overall, the population variability found will be useful for breeding programs for this species.

 

Genet. Mol. Res. 18(2): GMR18219
DOI: 10.4238/gmr18219
Research Article

Coffea canephora shows considerable variability for several agronomic traits, including nutritional efficiency. Beside the intrinsic nutritional efficiency of a genotype, the availability of water in the soil is another factor that can cause different responses, which suggests the possibility of selection of genotypes to enhance the nutritional efficiency under different scenarios, such as plantings in areas with low natural fertility or subjected to drought. We evaluated the genetic diversity of genotypes of C. canephora that compose the cultivar “BRS Ouro Preto”, the first available clonal cultivar recommended for Rondonia State, based on parameters of nutritional status of the plants subjected to cultivation under conditions of abundant water supply or subjected to water deficit. To this end, the experiment was developed with two trials where the 15 genotypes of this cultivar were cultivated in a greenhouse, under conditions of abundant water supply or subjected to water deficit. The trials followed a completely randomized design, with four replications and the mineral status of the plants was evaluated based on the content of N, P, K, Ca, Mg and S of their green tissues. The genotypes presented high variability for these nutritional parameters, making it possible to identify distinct patterns and to group them according to their nutritional status. Variability was affected by drought, showing that the water supply can cause changes in patterns of nutritional status and affect the clustering of genotypes. The genotypic effect surpassed the environmental influence for most mineral parameters, resulting in a desirable scenario for a possible selection to enhance nutritional efficiency, for both irrigated and rainfed systems, within the group of genotypes that already present high yield in Rondonia state.

 

Genet. Mol. Res. 18(2): GMR18300
DOI: 10.4238/gmr18300
Research Article

The development of common bean cultivars with biofortified grains for macrominerals and a seed coat color pattern that satisfies consumer preference is a new demand of breeding programs. However, combined selection for seed coat color and macromineral concentrations in common beans is unprecedented. The objectives of this work were to obtain estimates of genetic parameters for seed coat color and macromineral concentrations in a recombinant inbred line population of Mesoamerican common beans and to select superior common bean lines for a biofortification program. A biparental cross BRS Esteio × SCS 205 Riqueza resulted in 100 Mesoamerican common bean lines that were evaluated in the F5:6 and F5:7 generations. Seed coat color was evaluated in a colorimeter by values L* (white to black), a* (green to red), and b* (blue to yellow). Macromineral concentrations (potassium, calcium, and magnesium) were quantified by nitric‐perchloric acid digestion. A significant treatment effect for all traits evaluated at the F5:6 and F5:7 generations was observed. Seed coat color (L*, a*, and b* values) presented high heritability estimates (h2: 95.99 to 99.72%) and qualitative inheritance. Heritability estimates from intermediate to high magnitude (h2: 34.08 to 99.50%) were obtained for the concentrations of potassium, calcium, and magnesium. Transgressive segregation and quantitative inheritance for the macromineral concentrations were observed in the F5:7 generation. The four superior common bean lines selected by the index were L 83-17, L 69-17, BRS MG Pioneiro, and L 24-17. The lines L 83-17 and L 69-17 of black beans have darker grains (lower L*, a*, and b* values) and high concentrations of potassium, calcium, and magnesium. The lines BRS MG Pioneiro and L 24-17 of carioca beans present lighter grains (L* ≥ 55, a* ≤ 7 and b* ≤ 16), and high mineral concentration. These lines will be selected for a common bean biofortification program.

Genet. Mol. Res. 18(2): GMR18224
DOI: 10.4238/gmr18224
Research Article

Cancer is a public health problem of increasing concern worldwide due to the growing increase in mortality rates. The identification of natural compounds with cytotoxic activity is important due to the ready availability and their ability to act effectively in reducing the incidence of cancer, without adverse side effects. Whole grape juice (Vitis labrusca) is often consumed by the population, which is an example of a product with a high content of bioactive compounds, such as flavonoids and resveratrol. To help determine the suitability of this natural product as a health aid, we evaluated the cytotoxic activity of organic and conventional whole grape juices, exposed or not to UV-C irradiation, on human liver tumor cells (HepG2/C3A) and on non-tumor lung cells (MRC-5), by the MTT assay (a colorimetric assay for assessing cell metabolic activity), for 24 and 48 h. All of the juices, at the highest concentrations (50-100 µL/mL), showed significant cytotoxic activity on HepG2/C3A cells, reducing cell proliferation from 78 to 47%, in relation to the control, especially, after 48 h of treatment. Both conventional grape juices had cytotoxic effects on MRC-5 cells at 24 h of treatment, but cell proliferation was reestablished after 48 h. Furthermore, organic grape juice stimulated the proliferation of this cell line, especially that produced from grape exposed to UV-C, possibly in consequence of the increased amount of antioxidants, such as anthocyanins, resveratrol and flavonoids in the fruits, which probably stimulated cell metabolism. This data supports the use of whole grape juice, due to it’s nutraceutical potential, mainly because of antioxidant activity, in particular organic juice, and our findings demonstrate the benefit of food production techniques that add nutritional value, such as post-harvest exposure to UV-C.

Genet. Mol. Res. 18(2): GMR18236
DOI: 10.4238/gmr18236
Research Article

The efficiency of a selection index generally depends on the quality of the variance matrixes, which demands controlled experiments. Using Artificial Neural Networks (ANNs) trained from a selection index is advantageous for selecting genotypes since an ANN has the capacity to classify genotypes in an automated way. We propose the use of ANNs for the selection of alfalfa genotypes, based on a selection index. Data were collected from 77 alfalfa genotypes evaluated based on nine traits from four cuttings. The traits were divided into forage yield and nutritive value groups. In order for the ANNs to learn the classification pattern, the Tai index was used, which allows secondary traits to be included in the index to improve the gains of the main traits. An index was established for each group of traits, and based on the index scores the genotypes were subdivided into four classes (optimal, good, medium, and bad). After testing different topologies, ANNs were established for each index, according to the apparent error rates. The chosen ANNs were efficient in classifying the genotypes since the highest apparent error rate reached 15%, meaning that the ANNs efficiently captured the data pattern. Considering the ANN classification for both groups of traits, there was a high degree of agreement with the classification obtained from the Tai index, as expected. Even in the cuttings where the ANNs presented the worst performance, their potential to classify alfalfa genotypes was clear, because the wrong classifications were placed in groups close to the correct ones. This ensured that the best genotypes did not run the risk of being discarded, since they would not be classified in the group of bad genotypes. The ANNs that were developed have good potential for use in alfalfa breeding programs.

 

Genet. Mol. Res. 18(2): GMR18221
DOI: 10.4238/gmr18221
Research Article

Endometriosis is a chronic disease with adverse implications for fertility. We investigated the G894T polymorphism in the endothelial nitric oxide synthase gene in fertile and infertile women with endometriosis. This prospective study included a group of 52 women with a laparoscopic diagnosis of endometriosis. DNA was extracted from blood obtained from 47 patients and analyzed by PCR. The overall cohort was divided into infertile (n = 24) and fertile (n = 23) subgroups and compared in terms of genotypic and allelic frequencies. The genotypic distribution followed Hardy-Weinberg equilibrium (c2 = 2.21, P = 0.137) and included the GG genotype in 28/47 GT in 14/47, and TT in 5/47 of the samples. Genotypic and allelic frequencies between fertile and infertile women with endometriosis showed that absence of the TT genotype was associated with fertility in endometriosis patients (P = 0.0623). The T allele was present in 17 patients of the infertile group and 7 patients of the fertile group (P = 0.025). This allele was significantly associated with infertility (relative risk = 2.21, 95% confidence interval 1.56 - 3.08) for the recessive model of inheritance. Our findings suggest that women with endometriosis and the G894T polymorphism in the endothelial nitric oxide synthase gene are at increased risk of infertility.

 

Genet. Mol. Res. 18(2): GMR18201
DOI: 10.4238/gmr18201
Research Article

Corn is considered one of the most important crops in the world agricultural scenario. In order to improve production, it is crucial to understand and quantify the genetic variation involved in the phenotypic manifestation of this species. We characterized corn genotypes using a multivariate approach and examined canonical interrelations between characters of agronomic importance. The study was carried out in the 2016/2017 crop year in the southernmost state of Brazil, in the northwest region of Rio Grande do Sul. The treatments were composed of six open-pollinated corn genotypes (PL 712, PL 725, PL 796, PL 804 and PL 861). The experimental design was a randomized block with four replications. Analysis of variance revealed a significant difference at 5% of probability by the F test for the attributes plant height, ear insertion height, stem diameter, ear length, number of seed rows per ear, number of seeds per row of ear, thousand seed weight, seed yield, percentage of germination, first germination count, emergency percentage and cold test. Genetic variability analysis showed genotype PL 712 to have superior seed productivity. The physiological quality of the seeds produced was variable among the genotypes, but it followed the trend of superiority for PL 712. Linear associations revealed a tendency for tall stature plants to increase seed yield of open pollinated corn. The most polymorphic characters were plant height and ear insertion, response to cold test, and thousand seed weight. The productivity and seed quality trends that were observed will allow us to plan further research on open pollinated varieties to allow selection and development of superior genotypes for seed productivity and quality in the extreme south of Brazil.

 

Genet. Mol. Res. 18(2): GMR18123
DOI: 10.4238/gmr18123
Research Article

Several genes have been identified as important in athletic performance. The angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism has been related to improvements in performance and exercise duration. However, there are large divergences among studies on the influence of ACE I/D polymorphism on physical performance. Other studies have demonstrated that strenuous exercise generally overloads the endogenous antioxidant system’s capacity, leading to oxidative damage to muscles and other tissues in athletes. Few studies have reported significant associations between glutathione S-transferase (GST) deletion polymorphisms and resistance performance in athletes. We examined the effects of ACE I/D and GST deletion polymorphisms in young soccer players in central Brazil. We included 65 soccer players from under-20 (18 to 20 years old) soccer teams and 60 non-athletes in a case-control study. All subjects had their physical performance investigated through the Running-based Anaerobic Sprint Test (RAST). Genotyping was performed using real-time PCR. We found that the I/D genotype was significantly more frequent in athletes compared with the non-athletes. Individuals with the ID and DD genotypes had an approximately 3.13-fold and 4.37-fold increase in strength and power-orientated performance, respectively. The DD genotype in athletes presented RAST-test results considered as excellent to good when compared with non-athletes. When we examined a possible association of the GST deletion polymorphisms and RAST test, we found no influence on athletic performance. We did find association between ACE I/D polymorphism and athletic performance. However, there was no association between GST polymorphisms and risk of oxidative damage in the muscles. Our findings may help to select young players with the most favorable genetic potential to succeed as soccer athletes.

 

Genet. Mol. Res. 18(2): GMR18192
DOI: 10.4238/gmr18192
Research Article

The search for genetic material of snap beans with desirable yield traits is of utmost importance for yield increase in Brazil. We evaluated 12 snap bean genotypes by diallel crosses that presented characteristics of interest, so as to select the best genitors to generate productive populations in the snap bean breeding program of the Universidade Estadual do Norte Fluminense in Rio de Janeiro state, Brazil. Diallel crosses were performed applying Method 2 of Griffing. The F1 generation, composed of 36 hybrid combinations, was evaluated in a greenhouse, in a completely randomized design with two replicates. The traits evaluated were: pod weight, length, width and thickness, number of seeds and seed weight. There were significant differences among genotypes for most variables, indicating genetic variability between snap bean lines. The following genitor genotypes proved to be the most suitable when the trait to be improved was yield: Top Seed Blue Line, UENF 1445, UENF 7-20-1, and UENF 7-10-1. The hybrids with higher values of combining ability estimates are indicated to generate promising segregating populations. Thus L3 (Top Seed Blue Line) × L18 (UENF 9-24-2), and L12 (UENF 7-14-1) × L1 (UENF 1445) hybrid combinations showed the best estimates of specific combining ability for the traits under evaluation, suggesting a high probability of obtaining superior genotypes. The efficiency of selection for these traits is based on additive genic action and demonstrates progress in the of snap bean breeding program.

Genet. Mol. Res. 18(2): GMR18214
DOI: 10.4238/gmr18214
Research Article

Strawberry (Fragaria x ananassa) stands out among small fruits as the most planted in Brazil, generating considerable income and employment. However, producers are dependent on cultivars originating from international breeding programs and imported seedlings. This entails high costs and plants poorly adapted to the edaphoclimatic conditions of Brazil. In addition, the consumer market demands superior organoleptic and nutritional qualities. We assessed the potential of 194 hybrids for production and physicochemical characteristics from a population of seedlings obtained from intraspecific crosses of the short-day cultivars Dover, Camarosa, Sweet Charlie, Oso Grande, Milsei Tudla, and Festival Florida and the day-neutral cultivar Aromas. The experimental design was an augmented block design that had as control treatments the cultivars Camarosa and Camino Real. Five production and nine physicochemical characteristics were assessed. The mean comparison was performed by the Dunnett test. Among the 14 characteristics analyzed, eight presented significance. The significant production characteristics were the number of commercial fruits, mass of commercial fruits, mass of non-commercial fruits, and the total mass of fruits, with values of 45.03 fruits/plant, 13.17 g, 72.22 g/plant, and 720.77 g/plant, respectively. The physicochemical characteristics that varied significantly were soluble solids to titratable acidity ratio, pectin, ascorbic acid, and anthocyanin, which presented values of 10.23, 2.06 g total pectin/100 g pulp, 71.12 mg ascorbic acid/100 g pulp, and 39.51 mg cyanidin 3-glycoside/100 g pulp, respectively. The crosses that involved Camarosa and Aromas gave a greater number of hybrids with superior positive effects when compared to the controls in terms of production and physicochemical characteristics, respectively. Among the 194 hybrids, 30 were superior to the controls and were selected to advance in the breeding program.

 

Genet. Mol. Res. 18(2): GMR18156
DOI: 10.4238/gmr18156

Pages