Research Article

Table of Contents | Genet. Mol. Res. 2019 (3)

Displaying 1 - 15 of 17
Research Article

We appled a genetic and phenotypic multi-character predicted approach to the use of the multivariate methods Additive Main effects and Multiplicative Interaction (AMMI) and Genotype Main Effects and Genotype Environment Interaction (GGE). The experiment was carried out in the agricultural crop year of 2016 in the state of Rio Grande do Sul, Brazil. The experimental design was a randomized block design, with 14 growing environments x five wheat genotypes arranged in three replications. The characters were falling number, gluten strengthand protein content, which were used to make multi-character the technological index of the industrial quality of the wheat grains and multi-character the technological index of the industrial quality of the wheat grains. Multi-character selection can be a useful tool for identifying genotypes and growing environments that maximize the industrial quality of wheat grain. The GGE method provides greater explicability of the effects of genotype x environment interaction based on multi-character selection. The multicharacter genetic approach predicted for the selection of the industrial quality of wheat grain results in reliable inferences in the indication of adaptability and stability for the AMMI method and for GGE.

Genet. Mol. Res. 18(3): GMR18223
DOI: 10.4238/gmr18223
Research Article

Estimating the performance of a rice breeding program is possible by means of indexes such as the replacement rate, which quantifies the dynamism of the breeding program and provides the rate of included, excluded, maintained and renewed genotypes year after year. We evaluated the performance of the irrigated rice breeding program in the state of Minas Gerais, conducted by the EPAMIG/UFV/EMBRAPA consortium. A total of 210 lines were evaluated in the municipalities of Janaúba, Leopoldina and Lambari from 1993 to 2016. The average number of genotypes included, maintained and excluded in each year were calculated, along with the replacement rate percentage. The average genotype replacement rate was 44% for Lambari and Janaúba, and 43% for Leopoldina. The average maintenance in Lambari was 39%, and in Janaúba and Leopoldina it was 40%. In all localities, the mean rate of inclusion of genotypes was higher than the average exclusion rate, indicating good efficiency in the irrigated rice breeding program. However, new strategies should be used in the irrigated rice breeding program to increase the genetic basis of lines and increase the replacement rate.


Genet. Mol. Res. 18(3): GMR18332
DOI: 10.4238/gmr18332
Research Article

We evaluated how genetic x environment (G x E) interactions affect grain productivity in corn hybrids grown in traditional and non-traditional environments in the off or “second” season. Adaptability and stability of the hybrids was examined by parametric, nonparametric and multivariate methods. In 2016, 24 hybrids were evaluated in seven environments, in 2017, 13 hybrids were evaluated in six environments. The environments were located between the regions of Southwestern and Southeast Goiás state; Triângulo Mineiro and Alto Paranaíba, in the western and northwestern regions of Minas Gerais state. In all trials, complete randomized blocks were adopted, and grain productivity was determined. The statistical analyses were performed with two different softwares: Estabilidade and Genes. It was observed that in both seasons, the locals considered as traditional corn cultivation in the off season Jataí-GO and Montividiu-GO gave the highest yields, with average yields higher than national averages, producing 3859 kg.ha-1 in 2016 and 5562 kg.ha-1 in 2017. The methods of Eberhart and Russell, Lin and Binns modified by Carneiro, Centroid and AMMI gave similar results in the rankings of the adaptation and stability of the hybrids. We concluded that the G x E interaction for grain productivity of corn hybrids grown in the off-season is complex in nature.


Genet. Mol. Res. 18(3): GMR18193
DOI: 10.4238/gmr18193
Research Article

The production of peach rootstocks in Brazil is still performed mainly from seeds of different cultivars, whose endocarps are obtained in peach canning industries. This type of material is not ideal for use as rootstocks, since it is a varietal blend of genotypes with differing in physical and physiological characteristics which can include germination and growth of seedlings. We examined the genetic divergence of peach rootstock based on the relative contribution of 15 seed and endocarp characteristics, using multivariate procedures, in order to help select promising crosses for genetic improvement. Endocarp and seeds from eight rootstock cultivars of Prunus persica suggested as appropriate for cultivation in southern Brazil were evaluated for the biometric characteristics of length, width, thickness and fresh weight, and the seeds were submitted to a germination test. An analysis of variance of the data, principal component analysis and clustering using Tocher's optimization method were carried out. Genetic variability was found among the cultivars for all the characteristics. The characteristics with the greatest contribution to the genetic divergence between rootstocks were endocarp fresh weight, seed width and thickness, and germination percentage. On the basis of principal component analysis, using the variables with the greatest power of discrimination, the cultivars were divided into four groups. For breeding programs we suggest crosses between the cultivars Flordaguard χ Capdeboscq, Capdeboscq χ Tsukuba 1 and Capdeboscq χ Okinawa, aimed at obtaining improved peach rootstock with superior seed and seedling vigour, together with other characteristics of interest for farmers in southern Brazil.


Genet. Mol. Res. 18(3): GMR18345
DOI: 10.4238/gmr18345
Research Article

The species Syagrus romanzoffiana, a native palm tree of South America, is widely distributed and well adapted to southern Brazil. It is an important economic, cultural, and ecological resource, being the preferred food of diverse animal species, involving complex ecological relationships. However, despite numerous molecular studies on native plants, specific molecular markers, such as expressed sequence tag-simple sequence repeats (EST-SSRs), are lacking, and there are few SSR markers for this species. Molecular data about individuals and their populations offers new perspectives for management, conservation, and economic exploitation. Here we tested 21 microsatellite loci known from three species of the family Arecaceae in three native populations of S. romanzoffiana in the state of Rio Grande do Sul, in southern Brazil. Among the 21 primer pairs tested, 12 produced an amplification product. Five loci were chosen and subjected to diversity tests. The populations presented between three and nine alleles per locus, and acceptable genetic diversity values; the expected heterozygosity ranged from 0.460 to 0.864, while the observed heterozygosity ranged from 0.100 to 1.000. We conclude that various microsatellite markers developed for other species of the family Arecaceae are suitable for molecular analysis of S. romanzoffiana populations.

Genet. Mol. Res. 18(3): GMR18183
DOI: 10.4238/gmr18183
Research Article

During maturation in seeds, metabolic processes dependent on gene expression are controlled by hormones, including abscisic acid and gibberellin. These hormones determine dormancy or the capacity for germination in seeds and may have different expression levels in the endosperm and embryo of coffee seeds. We quantified gene expression in the biosynthetic pathway of gibberellin and abscisic acid in different parts of Coffea arabica L. seeds in pre and post physiological maturity, in order to better understand the germination mechanisms of this species. Coffee fruits were harvested at green, yellowish-green, cherry, over-ripe and dry stages. For studies of gene expression, intact seeds were used in addition to endosperm and isolated embryos. The RNA from different tissues was extracted and treated with DNAse to synthesize cDNA. Transition levels of CaGA3 (gibberellin) and CaABI3 (abscisic acid) genes were quantified with qRT-PCR, using specific primers for coffee. Intact seeds at each phenological stage were submitted to germination tests, to evaluate the physiological quality of the seeds.  Seed harvested at green and dry stages showed lower physiological quality when compared to the other maturation stages, and germination at the green stage was close to zero. Greatest expression of CaGA3 and CaABI3 occurs in the endosperm of coffee seeds in cherry and over-ripe stages, with better physiological performance. There are differences in CaABI3 and CaGA3 gene expression in embryos and endosperm of the coffee seeds.


Genet. Mol. Res. 18(3): GMR18264
DOI: 10.4238/gmr18264
Research Article

Atherosclerosis is a chronic multifactorial inflammatory disease that evolves in response to aggression of the endothelium, causing plaque formation in large or medium-sized arteries. Various co-factors can accelerate the evolution of this pathology, such as systemic arterial hypertension, dyslipidemia and diabetes mellitus. Given that nitrous oxide is a potent vasodilator and that its synthesis depends on the activity of the endothelial nitric oxide synthase (eNOS), we examined a possible association of the eNOS-T786C polymorphism (which reduces nitrous oxide synthesis) in atherosclerotic patients who have symptoms of hypertension, dyslipidemia or diabetes. We made a case-control study of two groups of 100 atherosclerotic patients, one with at least one of the above symptoms and the other a control group with atherosclerosis, but with none of the above symptoms. The samples were submitted to DNA extraction, then to PCR and analyzed on agarose gels. We found no significant association of the T786C (eNOS) polymorphism with the cofactors hypertension, dyslipidemia or diabetes. In addition, no association was found between smoking and eNOS T786C polymorphism. As for drinking, there was also no association with this polymorphism and or with cofactors.

Genet. Mol. Res. 18(3): GMR18269
DOI: 10.4238/gmr18269
Research Article

MC4R, FABP3 and DGAT1 are important genes related to productive and reproductive traits in pigs, such as food intake, growth rate, back fat thickness reduction and lactation. Selection of pigs for lean meat production may lead to losses in reproductive charcters because reduction of backfat thickness and low feed intake during the lactation phase can affect reproduction. To examine this possibility, we evaluated possible associations of SNPs in the MC4R (SNPg.1,578C>T), FABP3 (SNPg.240T>C) and DGAT1 (SNPg.9,422C>T) genes with the number of weaned piglets, birth weight, total weight of litter at birth, total litter weight at weaning, age at first mating and parity interval in 227 animals of two maternal lines: European and European/Chinese pigs. Specific fragments of the genes under study were amplified by Multiplex ARMS-PCR and genotyped in an automatic sequencer. SNPs in the MC4R (SNPg.1,578C>T) and FABP3 (SNPg-240T>C) genes showed three genotypic variations in both lines, while the SNP (SNPg.9,422C>T) of the DGAT1 gene had three genotypic variations in European swine and two genotypic variations (homozygotes) in the European/Chinese breed. Polymorphisms of MC4R, FABP3 and DGAT1 genes evaluated by variance analysis had significant associations with the reproductive traits age at first mating and parity interval, while only the DGAT1 gene in the European line was significantly associated with the production traits mean weight at weaning and total litter weight at birth andnd weaning.

Genet. Mol. Res. 18(3): GMR18139
Research Article

The CYP2C19*2 polymorphism is the result of a point mutation leading to an alternative splicing defect, generating an enzyme with a reduced function. The enzyme CYP2C19 is responsible for the activation of the prodrug Clopidogrel and the loss of its function leads to an increase in platelet aggregation. We compared the ARMS-PCR (Amplification Refraction Mutation System) and RFLP-PCR (Restriction Fragment Length Polymorphism) to determine which of the techniques was more efficient for identifying the CYP2C19*2 polymorphism. We analyzed 200 samples from patients with atherosclerosis and 100 samples from a control group, free from the disease. The polymorphic allele was not observed in any of the samples analyzed by the ARMS-PCR technique, but was present in more than 70% of the samples when analyzed by RFLP-PCR. Thus, RFLP-PCR generated more satisfactory results for the analysis of CYP2C19*2 polymorphism, and it should be used, despite the lower cost of ARMS-PCR, as the latter did not detect this polymorphism. 

Genet. Mol. Res. 18(3): GMR18268
DOI: 10.4238/gmr18268
Research Article

Diallel analysis and field tests have not been used in selecting for resistance to fusarium wilt in common beans (dry beans, Phaseolus vulgaris). Our goal was to select parents and segregating populations of dry bean (common bean) with black seed coat that are resistant to fusarium wilt and have high yield and high seed weight. Eight common bean cultivars and elite lines with some level of resistance to fusarium wilt based on previous evaluations, were used to make crosses in a complete diallel scheme. The 28 populations obtained were evaluated with two controls in trials in the F3 (winter/2012), F4 (winter/2013), and F5 (winter/2014) generations in randomized blocks, with three replications, in plots of two 4-meter rows. The trials were conducted in Santo Antônio de Goiás, GO, Brazil, in a field infested by Fusarium oxysporum f. sp. phaseoli in the winter growing season. Data were obtained on reaction to fusarium wilt, yield, and 100 seed weight. Individual and joint analyses of variance and diallel analysis were conducted on these data regarding reaction to fusarium wilt. Mean values were clustered using the Scott-Knott test. Genetic variability was detected for the three traits. There were significant differences among the general combining abilities of the parents and specific combining abilities of the populations for reaction to fusarium wilt, and the additive and non-additive effects were significant. The CNFP 15867 line is recommended for performing new crosses, because it exhibited a positive estimate of general combining ability (0.39), which indicates that it contributes to obtaining more resistant populations. The populations BRS Esplendor x BRS Expedito and BRS Expedito x CNFP 15867 were the most promising for extraction of lines, because they present high resistance to fusarium wilt (-2.6 and -2.8) and high grain yield (2212 and 2270 kg.ha-1), and acceptable seed weight (21.1 and 20.5 g/100grains).

Genet. Mol. Res. 18(3): GMR18276
DOI: 10.4238/gmr18276
Research Article

Deterioration and loss of seed germination in the germplasm are related to the aging that occurs during the conservation process. The mechanisms related to the aging and death of seeds are not yet fully understood, but it is known that longevity can be affected by moisture content and temperature. We examined the effects of accelerated aging (A.A.) on the DNA of seeds of three different cultivars of cowpea (Vigna unguiculata) and compared the data to data from vigor and germination tests. The DNA of A.A.-seeds of BR 17 Gurgueia, BRS-Marataoã and BRS-Guariba cowpea cultivars were extracted and subjected to agarose gel electrophoresis. The increase in temperature, relative humidity and time used in A.A. culminated in a progressive and increasing degradation of seed DNA, which was expressed by continuous bands of DNA molecules with different lengths in the electrophoresis gel under all but the most extreme conditions (combinations 45°C/72 h and 45°C/96 h at 100% relative humidity) under which total disintegration of the  DNA band was observed. This, in turn, was reflected in a progressive decrease in seed vigor. The combination of 35ºC/48 h was the most efficient for evaluating vigor in cowpea. The BR 17 Gurgueia and BRS-Guariba cultivars showed the highest values of vigor. A lack of DNA degradation in the laddering pattern on an electrophoresis gel is an indicator that DNA degradation and cell death in cowpea seeds did not occur by apoptosis but by non-programmed processes, such as Maillard reactions, lipid peroxidation and hydrolysis of sugars.

Genet. Mol. Res. 18(3): GMR18304
DOI: 10.4238/gmr18304
Research Article

Efficient analysis of datasets from multi-environment trials (MET) is of paramount importance in plant breeding programs. Several methods have been proposed for this purpose, each of them having advantages and disadvantages, depending on the objectives of the study. We examined the robustness in the predictive power of models that have been widely used in the study of genotype-by-environment interaction such as AMMI (additive main-effects and multiplicative interaction) models via EM algorithm, Bayesian AMMI models with homogeneity (BAMMI), heterogeneity of variances (BAMMI-H) and the Analytical Factorial model (FA). To check the efficiency of these methods, genotype and genotype- by- environment interaction effects were simulated and further unbalances were included at levels of 10, 33 and 50% loss of genotypes in the environments. To evaluate the predictive power of the proposed models, the PRESS (prediction error sum square) statistics and the Cor (correlation between predicted and observed value) were used. The genotype-environment interaction models had low sensitivity to missing data since all models showed correlations above 0.5 in all scenarios - even with high unbalance levels (50%). In general, there were differences in predictive accuracy among the models in different scenarios, with a slight advantage for the Bayesian models in the correlation among observed and predicted data ranging from 0.79 to 0.855 compared to 0.591 to 0.853 obtained from the competing models. Similar results were observed for the PRESS (4.988 to 8.027) in Bayesian models compared to competing models (5.411 to 23,361). Overall, there was slight advantage of the Bayesian models in unbalanced scenarios.


Genet. Mol. Res. 18(3): GMR18176
DOI: 10.4238/gmr18176
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 evaluated the agronomic performance of open pollinated genotypes, used by small scale family farmers, compared to commercial hybrid genotypes in various growing environments. The experimental design was a randomized block and the treatments were arranged in four replicates. Eight maize genotypes were used: three open-pollinated varieties and five simple hybrids. The following characters were measured plant height, ear insertion height, stem diameter, ear length, number of seed rows of the ear, number of seeds per row of ear, thousand seed weight and seed yield. The best yields of seeds were obtained in Entre-Ijuís, RS. Seed yield varied according to the genotype and growing environment; in Pelotas, RS the highest yields were obtained with the HC2 and HC1 genotypes (9090 and 9002 kg.ha-1, respectively). Genotypes with a narrow genetic base express less variation in their responses to the environments, in contrasting environments. Under limiting conditions the open pollinated varieties responded favorably. The use of biometric approaches allows us to reveal patterns in the grouping of genotypes.

Genet. Mol. Res. 18(3): GMR18180
DOI: 10.4238/gmr18180
Research Article

Anacardium occidentale (cashew) is a tropical tree species that occurs mainly in northeastern Brazil. The species has great socioeconomic importance for rural populations. We investigated the genetic diversity of a natural cashew population in a rural area of ​​Floriano, State of Piauí, Brazil. We quantitatively evaluated 12 natural variables related to the inflorescence, the cashew nut (fruit), and the peduncle (pseudofruit) in 35 trees (numbered sequentially G1-35). The characteristics of the peduncle (pseudofruit) appeared as the variables that most contributed to genetic divergence, while characteristics related to the inflorescence contributed less to the morphological differentiation. Multivariate statistics, employing principal component analysis evidenced that the first three principal components explained 81.72% of the total variance. Cashews G-3 and G-8 were identified as the most divergent, with G-3 demonstrating the greatest peduncle lengths and weights.


Genet. Mol. Res. 18(3): GMR18348
DOI: 10.4238/gmr18348
Research Article

Cassava (Manihot esculenta) is a traditional crop in tropical and subtropical regions that is used for human consumption and in animal feed. This studied cassava landraces cultivated in northern Mato Grosso State, Brazil, to detect the variability in family farms, aiming at the preservation and use potential of these genetic resources. A total of 120 M. esculenta individuals were evaluated at the rate of 40 per location (population), where each landrace was represented by 10 plants. The 14 microsatellite markers examined showed genetic diversity. The average polymorphic information content (PIC) was 0.621 and the average number of alleles per locus was seven. Genetic diversity parameters indicated that Ho was higher than He for the three populations, showing negative fixation indices and a lack of inbreeding. AMOVA revealed greater molecular variation within the populations (92%). Bayesian analysis and the UPGMA clustering method resulted in two main groups formed with the individuals distributed randomly; i.e., regardless of collection site (location). The gene flow found in this study is a consequence of the introduction and exchange of genetic material (landraces) performed by the farmers, who act on their farms as maintainers of local diversity. Manihot esculenta cultivation in northern Mato Grosso State ensure the on-farm conservation of genetic variability of the species and constitutes a source of genetic resources such as genes of resistance and adaptation, which can be exploited and utilized in breeding programs.


Genet. Mol. Res. 18(3): GMR18315
DOI: 10.4238/gmr18315