Research Article

Table of Contents | Genet. Mol. Res. 2017 (3)

Displaying 1 - 15 of 115
Research Article

Breeding programs currently use statistical analysis to assist in the identification of superior genotypes at various stages of a cultivar's development. Differently from these analyses, the computational intelligence approach has been little explored in genetic improvement of cotton. Thus, this study was carried out with the objective of presenting the use of artificial neural networks as auxiliary tools in the improvement of the cotton to improve fiber quality. To demonstrate the applicability of this approach, this research was carried out using the evaluation data of 40 genotypes. In order to classify the genotypes for fiber quality, the artificial neural networks were trained with replicate data of 20 genotypes of cotton evaluated in the harvests of 2013/14 and 2014/15, regarding fiber length, uniformity of length, fiber strength, micronaire index, elongation, short fiber index, maturity index, reflectance degree, and fiber quality index. This quality index was estimated by means of a weighted average on the determined score (1 to 5) of each characteristic of the HVI evaluated, according to its industry standards. The artificial neural networks presented a high capacity of correct classification of the 20 selected genotypes based on the fiber quality index, so that when using fiber length associated with the short fiber index, fiber maturation, and micronaire index, the artificial neural networks presented better results than using only fiber length and previous associations. It was also observed that to submit data of means of new genotypes to the neural networks trained with data of repetition, provides better results of classification of the genotypes. When observing the results obtained in the present study, it was verified that the artificial neural networks present great potential to be used in the different stages of a genetic improvement program of the cotton, aiming at the improvement of the fiber quality of the future cultivars.

Genet. Mol. Res. 16(3): gmr16039798
DOI: 10.4238/gmr16039798
Research Article

Geraniol is an acyclic monoterpene alcohol present in the essential oil of many aromatic plants and is one of the most frequently used molecules by the flavor and fragrance industries. The literature also reports its therapeutic potential, highlighting itself especially as a likely molecule for the development of drugs against cancer. In view of these considerations, this study was designed to evaluate the cytotoxic and genotoxic potential of geraniol, in an in vitro protocol, using two types of human cells: one without the ability to metabolize (peripheral blood mononuclear cells - PBMC), and the other with this capability (human hepatoma cell line - HepG2) through the comet assay and the micronucleus test. Four concentrations (10, 25, 50, and 100 µg/mL) were selected for the genotoxic assessment for PBMC and three (1.25, 2.5, and 5 µg/mL) for HepG2 cells based on cytotoxicity tests (MTT assay). Results showed that geraniol did not present genotoxic or clastogenic/aneugenic effects on both cell types under the conditions studied. However, caution is advised in the use of this substance by humans, since a significant reduction in viability of HepG2 and a marked decrease in cell viability on normal PBMC were verified.

Genet. Mol. Res. 16(3): gmr16039777
DOI: 10.4238/gmr16039777
Research Article

Resveratrol is an antioxidant that is a promising antitumoral, cardioprotective and neuroprotective agent. It has been found in a restricted number of plants including peanut (Arachis hypogaea L.) and its wild relatives. The objective of this study was to understand the relationship between resveratrol content and the expression of putative resveratrol synthase genes in four Arachis genotypes. Two diploids and two tetraploid were analyzed. Contents of resveratrol on non- and UV-treated leaves were estimated using HPLC. Resveratrol synthase (RS) was analyzed using RT-qPCR with primers developed in this study. Sequences of six Arachis species were amplified using two degenerated primer pairs that were designed based on Arachis and general RS available at GenBank. Those sequences were used to qPCR primers design. Test and control leaves were collected from plants cultivated in greenhouse and three biological replicates were evaluated for each genotype. The synthesis of resveratrol in leaves was induced by treatment with UV for 2.5 h. All genotypes studied synthesized resveratrol. Concentrations ranged from 193.66 µg/g in synthetic allotetraploid to 371.97 µg/g in A. duranensis. Natural and induced allotetraoploids showed lower levels of resveratrol than their diploid parents. Untreated samples did not produce significant amounts of resveratrol. The analysis of resveratrol content and levels of RS mRNA allowed the identification of one gene induced by the UV treatment. The data showed different amounts of RS in the different genotypes suggesting early and late response to the UV induction in the different species. The understanding of the variation found among species will help to identify species that have high resveratrol content and their ideal pos-induction times. This also will allow analysis of other tissues where high levels resveratrol would be very important, such as in seeds.

Genet. Mol. Res. 16(3): gmr16039802
DOI: 10.4238/gmr16039802
Research Article

Diarrhea is considered the second most common cause of infant mortality worldwide. The disease can be caused by many different pathogens, including diarrheagenic Escherichia coli (DEC), which includes the pathotypes enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), Shiga toxin-producing E. coli (STEC), and enteropathogenic E. coli (EPEC). To develop a multiplex PCR system for the safe and accurate identification of the five main pathotypes of DEC, seven pairs of primers were determined for the following genes: aaiC, escV, bfpA, ipaH, elt, stx1, and stx2. To validate the system, 413 isolates from different sources (water and both animal and human stool) were analyzed that had been characterized previously. The sensitivity data were grouped by pathotype, in which 92.7% of the atypical EPEC were correlated, as were 92.8% of the STEC, 91.35% of the EAEC, and 100% of the typical EPEC, ETEC, and EIEC. These findings indicate that it is possible to detect the major five pathotypes of DEC from different sources, which can aid in determining the epidemiology of diarrhea with a low cost, high sensitivity and specificity, and the easy and safe viewing of the resulting PCR products.

Genet. Mol. Res. 16(3): gmr16039760
DOI: 10.4238/gmr16039760
Research Article

In this study, the temperature and pressure of supercritical CO extraction were evaluated to obtain oleoresin of Brunfelsia uniflora leaves and flowers. The oleoresin compounds were identified by gas chromatography-mass spectrometry. The antioxidant activity was evaluated by three different methods. The highest oleoresin yields were 3.32% at 40°C and 200 bar for the leaves, and 1.03% at 60°C and 200 bar for the flowers. The main extracted compounds from leaves were phytol varying from 11.95 to 36.42% and α-tocopherol from 15.53 to 43.10%, and from flowers were geranyl linalool from 11.05 to 21.42% and α-amyrin from 9.66 to 22.12%. Oleoresin obtained at 60°C and 150 bar from leaves presented high antioxidant activity by DPPH (IC 1.90 mg/mL) and by FRAP (1.8 µmol Fe/mg). β-carotene/linoleic acid co-oxidation oleoresin from leaves at 0.25 mg/mL presented higher antioxidant activity than Trolox. The total phenolic content of the oleoresin from leaves ranged from 66.20 to 83.33 µg/mg and from flowers it was just up to 12.46 µg/mg. The extraction conditions affected yield, chemical composition, and antioxidant activity of oleoresin from leaves and flowers. This is the first report on the antioxidant activity of B. uniflora oleoresin from leaves and flowers and provides subsidies for potential applications in chemical, pharmaceutical, and food industries.

Genet. Mol. Res. 16(3): gmr16039714
DOI: 10.4238/gmr16039714
Research Article

Goats are the Pakistan's fastest growing ruminants, and Pakistan is the third largest goat producer in the world after India and China. Goat meat preference is the main reason for its increased demand. In the country, there are 25 goat breeds and two wild relatives such as Mark and Goats. At present, Pakistan has 53.8 million goats, according to the 2006 GOP report, and their population growth rate was more than 3% per year (37, 23, 22, and 18% of the goat population in Punjab, Sindh, Balochistan, and NWFP, respectively). Peste des petits ruminants virus (PPRV) belongs to the family Paramyxoviridae and is considered to be one of the major constraints on increasing the productivity of goats and sheep in the areas where they exist and become local. It is closely related to cattle and buffalo rinderpest virus, dogs and other wild predator distemper virus, human measles virus, and marine mammalian measles virus. The present study aimed to determine the screening of the PPRV, Capra Hircus Lin. population, in the Khairpur Mirs District, Sindh, Pakistan. We selected 290 goats for serum sample collection and analysis using competitive ELISA kits according to the manufacturer's instructions. Our results showed that 59 (64%) of the 92 clinical cases were positive and 33 (36%) were seronegative. The study concluded that PPR might be more prevalent in the Khairpur District. Furthermore, it is highly recommended to use homologous PPR-attenuated vaccines to prevent lethal virus attacks that control PPR in the country.

Genet. Mol. Res. 16(3): gmr16039679
DOI: 10.4238/gmr16039679
Research Article

Iron (Fe) is an essential microelement for all living organisms playing important roles in several metabolic reactions. Rice (Oryza sativa L.) is commonly cultivated in paddy fields, where Fe goes through a reduction reaction from Fe3+ to Fe2+. Since Fe2+ is more soluble, it can reach toxic levels inside plant cells, constituting an important target for studies. Here we aimed to verify morphological changes of different rice genotypes focusing on deciphering the underlying molecular network induced upon Fe excess treatments with special emphasis on the role of four WRKY transcription factors. The transcriptional response peak of these WRKY transcription factors in rice seedlings occurs at 4 days of exposition to iron excess. OsWRKY55- like, OsWRKY46, OsWRKY64, and OsWRKY113 are up-regulated in BR IRGA 409, an iron-sensitive genotype, while in cultivars Nipponbare (moderately resistant) and EPAGRI 108 (resistant) the expression profiles of these transcription factors show similar behaviors. Here is also shown that some cis-regulatory elements known to be involved in other different stress responses can be linked to conditions of iron excess. Overall, here we support the role of WRKY transcription factors in iron stress tolerance with other important steps toward finding why some rice genotypes are more tolerant than others.

Genet. Mol. Res. 16(3): gmr16039694
DOI: 10.4238/gmr16039694
Research Article

This study aimed at identifying and selecting through partial diallel analysis, segregating populations of cowpea resistant to Macrophomina phaseolina and Thanatephorus cucumeris, based on the evaluation of general (GCA) and specific combining ability (SCA), involved in the genetic control of resistance. For this reason, 19 grouped cowpea genotypes, considering the resistance to these pathogens, were crossed in partial diallel scheme 14 x 5, during 2013 and 2014. The 70 F populations and the 19 parents were evaluated in a greenhouse as the reaction to pathogens, separately. The diallel analysis was performed according to the model of partial diallel proposed by Geraldi and Miranda Filho (1988). The additive effects predominated in the genetic control of the traits severity of charcoal rot (SEV) and area under the disease progress curve (AUDPC) to web blight, enabling the achievement of genetic gain with selection of resistant strains. Analyzing the effects of GCA, the parents BR 14-Mulato, BRS Tumucumaque and BRS Guariba, have a higher concentration of favorable alleles, highlighting, according to the values of SCA, the combinations BR 14-Mulato x MNC02-675F-4-10, BRS Tumucumaque x IT98K-1092-1, BRS Tumucumaque x MNC02-675F-4-10, BRS Tumucumaque x MNC02-675F-9-2, BRS Guariba x IT98K-1092-1, BRS Guariba x MNC02-675F-4-9, and BRS Guariba x MNC02-675F-4-10, as the most promising and indicated to obtain lines resistant to M. phaseolina and T. cucumeris in cowpea, simultaneously.

Genet. Mol. Res. 16(3): gmr16039804
DOI: 10.4238/gmr16039804
Research Article

Elephant grass is a perennial tropical grass with great potential for energy generation from biomass. The objective of this study was to estimate the genetic diversity among elephant grass accessions based on morpho-agronomic and biomass quality traits and to identify promising genotypes for obtaining hybrids with high energetic biomass production capacity. The experiment was installed at experimental area of the State Agricultural College Antônio Sarlo, in Campos dos Goytacazes. Fifty-two elephant grass genotypes were evaluated in a randomized block design with two replicates. Components of variance and the genotypic means were obtained using a Bayesian multi-trait model. We considered 350,000 iterations in the Gibbs sampler algorithm for each parameter adopted, with a warm-up period (burn-in) of 50,000 Iterations. For obtaining an uncorrelated sample, we considered five iterations (thinning) as a spacing between sampled points, which resulted in a final sample size 60,000. Subsequently, the Mahalanobis distance between each pair of genotypes was estimated. Estimates of genotypic variance indicated a favorable condition for gains in all traits. Elephant grass accessions presented greater variability for biomass quality traits, for which three groups were formed, while for the agronomic traits, two groups were formed. Crosses between Mercker Pinda México x Mercker 86-México, Mercker Pinda México x Turrialba, and Mercker 86-México x Taiwan A-25 can be carried out for obtaining elephant grass hybrids for energy purposes.

Genet. Mol. Res. 16(3): gmr16039803
DOI: 10.4238/gmr16039803
Research Article

Estimating genotype x environment (GxE) parameters for quality and yield in soybean seed grown in different environments in Minas Gerais State was the goal of this study, as well as to evaluate interaction effects of GxE for soybean seeds yield and quality. Seeds were produced in three locations in Minas Gerais State (Lavras, Inconfidentes, and Patos de Minas) in 2013/14 and 2014/15 seasons. Field experiments were conducted in randomized blocks in a factorial 17 x 6 (GxE), and three replications. Seed yield and quality were evaluated for germination in substrates paper and sand, seedling emergence, speed emergency index, mechanical damage by sodium hypochlorite, electrical conductivity, speed aging, vigor and viability of seeds by tetrazolium test in laboratory using completely randomized design. Quadratic component genotypic, GXE variance component, genotype determination coefficient, genetic variation coefficient and environmental variation coefficient were estimated using the Genes software. Percentage analysis of genotypes contribution, environments and genotype x environment interaction were conducted by sites combination two by two and three sites combination, using the R software. Considering genotypes selection of broad adaptation, TMG 1179 RR, CD 2737 RR, and CD 237 RR associated better yield performance at high physical and physiological potential of seed. Environmental effect was more expressive for most of the characters related to soybean seed quality. GxE interaction effects were expressive though genotypes did not present coincidental behavior in different environments.

Genet. Mol. Res. 16(3): gmr16039801
DOI: 10.4238/gmr16039801
Research Article

Molecular identification of hybrid purity is difficult in regional trials of cotton varieties and hybrid trials. In particular, the molecular detection of hybrid purity has not yet been reported in the case of unknown parentage. In this study, we screened 5000 pairs of primers and chose 17 pairs of core simple sequence repeat (SSR) primers to determine the F1 purity of Han6402. The results showed that the purity based on SSR markers reached 100%. Twelve of the 17 pairs of primers exhibited co-dominant banding patterns, and 5 showed non-co-dominant banding patterns. Moreover, we constructed an F1 SSR fingerprinting profile that enabled the identification of the authenticity of Han 6402. Using these primers, we subsequently detected 44 individual F2 seedlings, and the results exhibited different extents of separation, in which the majority of genotypes were heterozygous with co-dominance at most of the loci that differed from each other. The results validated the underlying heterozygous status of the F2 population at the molecular level. Therefore, we conclude that the set of core SSR primers can be used for the laboratory identification of the authenticity and purity of cotton hybrids, not only for distinguishing Fl hybrids or segregating F2 populations, but also for detecting volunteer seeds as fake F1 hybrids in the cotton hybrid industry, based on the hybrid fingerprinting.

Genet. Mol. Res. 16(3): gmr16039799
DOI: 10.4238/gmr16039799
Research Article

One hundred and eighty-two samples of unrelated people who requested the paternity test at the Molecular Biology and Genetics Laboratory of the Catholic University of Cuenca-Ecuador in the province of Azuay were studied, except for the D1S1656 (180 samples) and SE33 (89 samples) markers. The STRs D22S1045, D3S1358, VWA, D16S539, D2S1338, D8S1179, D21S11, D18S51, D19S433, TH01, FGA, D1S1656, D12S391, D10S1248, D2S441, and SE33 were typed from blood samples, amplifying the DNA by polymerase chain reactions and electrophoresis. The allele frequencies were estimated by simple counting and the impartial heterozygosity was also calculated. The Hardy-Weinberg equilibrium theory was studied. In the results obtained with the analyzed markers, the largest number of alleles can be observed in the markers with the highest polymorphic information content (PIC): D21S11, D16S539, D2S1338, D19S433, D18S51, FGA, D1S1656, and D12S391. In addition, SE33 was analyzed in certain samples, showing as result a high PIC, in fact, the highest one because of its great polymorphisc characteristic. Likewise, these markers are the ones providing the highest probability of discrimination and the lowest probability of coincidence.

Genet. Mol. Res. 16(3): gmr16039797
DOI: 10.4238/gmr16039797
Research Article

In order to obtain the certificate of cultivar protection, it is necessary to prove its distinctiveness, homogeneity, and stability. Currently, there are 37 descriptors for differentiating soybeans cultivars. However, they are still not enough and, as a result, it is necessary to create, identify, and evaluate new descriptors. This study was aimed at evaluating the genotypic and environment interaction (GxE) and determining the stability of eight soybean cultivars for five vegetative-stage descriptors. The research was done in a greenhouse of the Soybean Breeding and Genetic Studies Program of Universidade Federal de Uberlândia. The treatments were composed of eight soybean cultivars, sown in two different growing seasons (January 25, 2014 and November 27, 2014). The experiments were carried out in randomized complete blocks with three replications and each experimental plot consisted of one pot with four soybean plants. The characters evaluated were: length of hypocotyl (LH), length of epicotyl (LE), length of unifoliolate leaf petiole (LUP), length of first trifoliate leaf petiole (LTLP), and rachis length of terminal leaflet of the first trifoliate leaf (RL). The data achieved from the trials were undergone genetic-statistical analyses by the GENES software. For all analyzed characters, the existence of genetic variability was observed emphasizing the vegetative-stage descriptors' utility to differentiate soybean cultivars. The occurrence of GxE interaction was detected for all characters assessed, mainly of complex nature, except by RL, which was of simple nature. The most stable cultivars for the vegetative-stage descriptors analysed were UFUS 7415 and UFUS Impacta.

Genet. Mol. Res. 16(3): gmr16039795
DOI: 10.4238/gmr16039795
Research Article

This study aimed to identify Capsicum genotypes with resistance to bacterial spot (BS), anthracnose and Pepper yellow mosaic virus (PepYMV). Fifty-four genotypes of Capsicum spp were evaluated. Resistance reaction against BS was evaluated using three replicates, testing hypersensitivity and quantitative resistance in leaves. After evaluation, inoculated leaves were detached from the plants, being then cultivated until reproductive stage for evaluations anthracnose resistance in immature and mature fruit, totalizing 18 fruits per genotype. For PepYMV resistance was performed with five replications. Each genotype reaction was evaluated by a scoring scale, using the area under the disease progress curve for each pathosystem, and incubation period for the three systems. The latent period was evaluated only for the pathosystem Capsicum-Colletotrichum gloeosporioides. Means were grouped by the Scott-Knott test. Measures of dissimilarity matrix among the genotypes were obtained by Gower's algorithm and the grouping was obtained by the UPGMA clustering method. The accessions belonging to the Capsicum frutescens were the most susceptible to the three diseases. At least one genotype of Capsicum baccatum var. pendulum, Capsicum annuum, and Capsicum chinense showed resistance potential to BS and PepYMV, for use in breeding programs. The accession UENF 1381 (C. annuum) was resistant to the three pathogens.

Genet. Mol. Res. 16(3): gmr16039789
DOI: 10.4238/gmr16039789
Research Article

Biplot analysis has often been used to recommend genotypes from different crops in the presence of the genotype x environment interaction (GxE). The objective of this study was to verify the association between the AMMI and GGE biplot methods and to select soybean genotypes that simultaneously meet high grain yield and stability to the environments belonging to the Edaphoclimatic Region 402, from Soybean Cultivation Region 4 (Mid-West), which comprises the Center North and West of Mato Grosso, and the southern region of Rondônia. Grain yield of 12 soybean genotypes was evaluated in seven competition trials of soybean cultivars in the 2014/2015 harvest. Significant GxE interaction revealed the need to use methods for recommending genotypes with adaptability and yield stability. The methods were complementary regarding the recommendation of the best genotypes. The AMMI analysis recommended MG/BR46 (Conquista) (G10) widely for all environments evaluated, whereas the BRY23-55012 (G9) and BRAS11-0149 (G2) were the most indicated genotypes by the GGE biplot method. However, the methods were concordant as to Porto Velho (PV1) environment that contributed least to the GxE interaction.

Genet. Mol. Res. 16(3): gmr16039786
DOI: 10.4238/gmr16039786