Table of Contents | Genet. Mol. Res. 2019 (1)
Gamma radiation is commonly used to disinfect agricultural products to increase shelf-life. However, this may exert adverse effects on plant growth, development, fertility, and crop production due to oxidative stress and cellular damage. Post irradiation protection using nanoparticles could reduce or reverse deleterious effects after exposure to ionizing radiation. We monitored the effect of zinc oxide nanoparticles (ZnO NPs at 500, 2000, 4000 mg/L) on Vicia faba grown from seeds treated with gamma rays (20, 50, 100 Gy). Phenotypic (seed germination, percentage of inhibition, seedling growth) and cytogenetic markers (chromosomal behavior in mitosis, meiosis and pollen grains) along with ultrastructural changes in the chloroplasts and nuclei (transmission electron microscopy) were assessed. At 20 Gy radiations, ZnO NPs had no effect on the final germination percent; however, at 100 Gy and post-treatment with 4000 mg/L of ZnO NPs, a substantial reduction occurred. While vegetative growth and fruit production increased with 500 and 2000 mg/L ZnO NPs, all three doses of gamma rays induced reduction. ZnO NPs provoked a significant increase in the mitotic index of root meristems compared with the control and gamma radiation. A radioprotective effect of ZnO NPs in the mitotic-meristematic root tips of V. faba was observed. The degree of mutagenic efficiency and pollen grain sterility was dose-dependent. Chloroplasts and nuclei treated with higher concentrations of ZnO NPs (4000 mg/L) and the three doses of gamma rays showed adverse ultrastructural changes. An amelioration or modulation of these changes was observed post irradiation with 500 and 2000 mg/L ZnO NPs. ZnO NPs at 500 and 2000 mg/L concentrations had protective effects through the reduction of adverse effects of all doses of gamma rays at the phenotypic, cytogenetic, and cellular ultrastructure levels. Additional studies are warranted to explore ZnO NPs as potential nano-irradiation protective agents.
Heterozygosis for the hemoglobin S allele is a relatively common condition that is clinically benign and rarely presents clinical or hematological manifestations. Although rare, symptoms have been reported in these patients. We examined clinical manifestations and laboratory findings in HbAS individuals that could be related to the βS haplotypes: in 31 heterozygotes, with a predominance of females and young adults, and 43 AA homozygotes considered as a control group from samples previously stored in our laboratory. We performed clinical, biochemical and hematological tests, as well as genotyping by PCR-RFLP for the identification of βS haplotypes. Bantu and Benin haplotypes were equally frequent (n= 7, each) and 17 individuals had shown atypical haplotypes. We observed hematological alterations (e.g. mean corpuscular volume levels) that suggest microcytic and hypochromic anemia; however, we did not find iron deficiency anemia or thalassemia. In the clinical examination, the heterozygote individuals reported pain, especially in the upper and lower limbs and joints, as the most frequent complaint. HbS heterozygotes, different from literature reports, had a significantly greater frequency of anemia-related parameters when compared to normal homozygotes.
Plant tolerance to abiotic stresses, such as water deficit, is triggered by complex multicomponent signaling pathways. One of the plant responses to stress conditions is expression of a large number of genes whose products are involved in various adaptive functions. Transcription factors (TFs) are important regulators of gene expression, modulating the transcription initiation rate of target genes; they are critical components in signal transduction in response to abiotic stress. Our hypothesis is that genotypes with contrasting tolerance signal water deficit through TFs (10 genes of the DREB family and bZIP) with differing degrees of expression. We believe that these genes will have greater expression in the flooded genotype because drought is an atypical condition in these plants. We tested two rice (Oryza sativa) genotypes: BRS Querência (flooded) and AN Cambará (dryland). When they reached stage V5, the plants were submitted to water deficit, at different levels of soil moisture, 20%, 10% and recovery. In general, we observed that expression varies according to the soil moisture and the genotype. In addition, the coexpression analysis generated seven cluster interactions with several genes. Our hypothesis was confirmed in part; the contrasting genotypes gave different degrees of expression; however, we ca not affirm that the flooded genotype has more significant responses in dry soil because there were variations in expression demonstrating oscillation in metabolism, and the data do not allow us to associate expression with greater drought tolerance.
This is the first scientific record of Melanagromyza sojae in Bolivia, confirmed through molecular characterization of the mtDNA COI gene. Commonly known as the soybean stem fly, M. sojae belongs to the family Agromyzidae and is a highly polyphagous pest, attacking several plant species of the Fabaceae family, such as soybeans and other beans. Previously reported in Brazil and Paraguay, the soybean stem fly presence was confirmed in soybean fields of the municipalities of Fernández Alonso, Cuatro Cañadas, Santa Cruz de la Sierra, Yapacani and Santa Rosa del Sara, which are located in Santa Cruz Department, Bolivia. This soybean stem fly detection in Bolivia will affect soybean crop practices in South America.
Many of the plants that grow in arid and semi-arid regions under harsh conditions (drought, salinity and misuse) are of medical importance. Desert plants also provide other benefits; so conservation efforts should be strengthened in these areas. In this study, three DNA barcodes – chloroplast maturase-K (matK), ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcL) and secondary internal transcribed spacer (ITS2) – were tested in order to determine the ability of these markers to distinguish between various species. A total of 93 fresh and dry samples belonging to 30 plant families were examined. These are native to the arid lands around Makkah in the Kingdom of Saudi Arabia. Various tools and tests were used to evaluate the efficiency of the barcode markers; these included the basic local alignment search tool (BLAST), as well as the use of inter- and intraspecific distances, barcode gap, prediction of the secondary structure of the ITS2 and phylogenetic methods. The results confirmed the efficiency and superiority of the ITS2 loci over two chloroplast genes: matK and rbcL. ITS2 had a 97% success rate with amplification and a 95% success rate with sequencing, showing 100% identification at the family level, 77% identification at the genus level and 70% species resolution. A clear barcode gap was observed between inter- and intraspecific distances. Identification was achieved even in cases of degraded samples or old herbarium specimens. This study contributes to DNA barcode data by adding 224 DNA sequences of desert plants to the National Center for Biotechnology Information NCBI database. The results of this study are important and useful for application in each of the following fields: validation of medicinal plant identity, conservation, and taxonomic and evolutionary studies.
The objectives of this study were to select promising common bean populations for high iron and zinc contents (FeC and ZnC), seed yield and 100-seed weight, to study the genetic control of these traits and to select parents for high FeC and ZnC based on a diallele analysis. Fifteen populations were obtained from crosses among six parents selected for high FeC and ZnC using a complete diallel scheme. The 15 populations were evaluated together with two control cultivars/lines (Pérola and Piratã 1). The following traits were evaluated: FeC and ZnC in four environments/generations and seed yield and 100-seed weight, in three environments/generations. Individual and joint analyzes of variance were performed for the four traits and individual and joint diallel analyzes for FeC and ZnC. Significant differences were found among populations for all traits, which demonstrates genetic variability that can be exploited. For FeC, the additive effects were more important and the white seeded line G 2358 stood out for high general combining ability (5.63), being for this reason indicated as a parent. For ZnC, both additive and non-additive effects were important. The populations selected as simultaneously superior for the four traits were Porto Real x G 2358 and BRSMG Majestoso x G 2358, with at least one parent with carioca seeds; and BRS Requinte x BRSMG Majestoso, Porto Real x BRS Requinte and Porto Real x BRSMG Majestoso, with carioca seeds. The BRS Requinte x G 2358 population is recommended to obtain lines with high FeC and ZnC.
The cowpea, Vigna unguiculata (Fabeaceae) is widely cultivated in semi-arid regions, such as northeast Brazil. Due to the low crop yields in this region, it would be useful to develop cultivars adapted to these climate conditions. Landraces are seen as an important source of germplasm to be used in breeding programs of this species due to their good adaptation to the environment, but for this strategy to be viable, their genetic variability must be studied. To this end, we evaluated the genetic diversity, using ISSR molecular markers, of 52 samples of cowpea landraces collected mostly from small producers from all over the state of Ceará, Brazil. The DNA of the genotypes was extracted and analyzed using 25 primers. Based on the electrophoresis profiles of the bands, a genetic dissimilarity matrix was prepared, and a cluster analysis made using the UPGMA and modified Tocher methods. Fourteen primers amplified 80 bands, of which 61 were polymorphic, generating a polymorphism rate of 76%. The selected markers were efficient in identifying genetic variability among the varieties under evaluation, providing a large amount of information. The polymorphic information content varied from 0.13 to 0.66 and the band frequency ranged from 0.01 to 1.00. The two clustering methods agreed in the number of groups formed (n = 6), with the genetic distances ranging from 0.05 to 0.31, values considered low, suggesting a narrow genetic base for the landraces of this species in Ceará state.
Worldwide, several women become victims of rape every day. Many of those women are also murdered, with their bodies sometimes being found in an advanced state of decomposition, resulting in loss of evidence important to criminal investigations. Diptera is one of the main orders associated with human body decomposition. Fly species that belong to the family Calliphoridae are usually scavengers and are frequently found on decomposing bodies, thereby playing an important role in forensic entomology. The recovery and genotyping of human Y-STR DNA from the gastrointestinal contents of the calliphorid Chrysomya albiceps larvae has promising applications in the investigation of sexual crimes, such as rape, and in cases of murder and abandonment of the victim’s body, which may be found in a state of decomposition. We studied this species of fly with the aim of supporting such investigations. After establishment of a colony, larvae were fed with decomposing human semen mixed in ground bovine meat (1 mL per 200 g beef). Larvae (10–15) were collected every 24 h and kept in 70% ethanol, to give a total of 96 larvae obtained after eight days of decomposition. The digestive system of each larva was resected. Molecular typing was conducted, which comprised sample extraction, quantification, amplification, and capillary electrophoresis with 16 STR loci from the Y chromosome. We succeeded in establishing a Y-STR DNA profile, with amplification of up to 11 loci, from individual samples, or up to 15 loci, when a combination of samples corresponding to the time-points 48, 72, 120, 144, and 192 h was used.
Passiflora cristalina, Passiflora miniata and Passiflora coccinea are wild species with similar floral characteristics, especially color and floral structure, as well as the color of their fruits. Due to their similarities, mainly the floral characteristics, these species are often confused in the field. Given that hybridization is commonplace between Passiflora species in the same region, hybrids could result from crosses involving mainly P. coccinea. We examined genetic distance and possible hybrid nature across P. cristalina, P. miniata, and P. coccinea, via ISSR and SSR markers. Genomic DNA was extracted from leaf samples of five Passiflora species (P. cristalina, P. coccinea, P. miniata, P. setacea, and P. edulis), the latter two being used as witness species. Following quantification, the amplification conditions were tested and optimized. Eighteen ISSR primers presented satisfactory amplification products, with 81 bands being amplified and 99% polymorphism. Through genetic distance and cluster analysis, P. cristalina and P. coccinea were found to be genetically close, while P. miniata remained in an isolated cluster, nevertheless with low dissimilarity with P. cristalina. Twenty-three SSR primers were tested, of which 18 were polymorphic. There was a high transferability rate, 95.65%, demonstrating that genetic proximity between tax is directly related to successful transferability. The main coordinates, genetic distance and cluster analyses showed a clear separation of species presenting similar floral characteristics (P. cristalina, P. coccinea, and P. miniata) from the remaining ones used as controls (P. edulis and P. setacea). SSR markers identified P. cristalina as a possible natural hybrid between P. miniata and P. coccinea.
The soybean crop is undoubtedly important to not only Brazil but also for most parts of the globe, as economic and social dependency upon this crop becomes evident. However, the scenario of the soybean crop production has faced challenges with environmental changes, which have escalated the incidence of pests. Due to the abundance of stink bugs, especially Euschistus heros in tropical regions, they can considerably impact the productivity of the crop compromising total grain yield and seed quality. Therefore, this research was aimed to evaluate soybean lines with desirable agronomic traits under high natural infestation of Euschistus heros and to access the genotypic and phenotypic correlations between important agronomic traits for soybean breeding. Twenty-three soybean F8 lines developed by the Soybean Breeding Program of Federal University of Uberlândia and four cultivars (Msoy 8527, UFUS Xavante, Msoy 8787, and UFUS Milionária) were evaluated under randomized complete block design with three repetitions during the growing season of 2015/2016 and 16 agronomic traits were accessed. There was genetic variability for all traits but Asian soybean rust severity at 1% probability level through F test. For all traits in the study but the total number of pods and Asian soybean rust severity, the coefficient of genotypic determination was superior to 70%, indicating that the most part of phenotypic variability was due to genetic differences among the genotypes in study. Grain yield was demonstrated to be a useful trait for indirect selection of soybean genotypes with resistance to brown stink bugs. Also, early cycle genotypes, heavy seeds and a higher number of pods revealed a positive correlation with grain yield over the same conditions. The lines G1, G2, and G24 are very promising genotypes as they have shown valuable agronomic traits for stink bug resistance.
Genipap (Genipa americana - Rubiaceae) is native to tropical America, occurring in Brazil in practically all biomes, except in the Pampas. It has socioeconomic importance, mainly due to the use of fruits in the manufacture of sweets and juices besides the medicinal properties of its leaves. We evaluated the genetic diversity of 73 individuals from 15 natural populations in the state of Sergipe using ISSR markers. The choice of areas was made randomly and genetic material was extracted from young leaves. PCR analysis using nine markers generated 113 fragments, which were used to estimate genetic diversity. The Shannon index was 0.36 and the similarity of individuals varied between 0.11 and 0.81. The individuals Salgado 3 (SAL3) and Salgado 4 (SAL4) were the most similar (0.81) and seven pairs had low similarity (0.11). The genetic distance the UPGMA analysis, which divided individuals into two distinct groups. The level of genetic variability found allows differentiation between genotypes that can be used to enrich the Genipap Active GermPlasm Bank in Sergipe, and the information generated will be useful for the conservation of these genetic resources and in future breeding programs for this species.
The parasitic protozoan Perkinsus marinus (Perkinsidae) is known to infect marine bivalves; unfortunately, treatment options are quite limited. The parasite is associated with mass mortalities worldwide and it requires notification to the World Organization for Animal Health (OIE). In Brazil, since the first report of P. marinus infecting Crassosstrea rhizophorae in the state of Paraíba in 2013, populations of oysters have been subject to continuous surveillance programs by the Ministry of Agriculture, Livestock and Food Supply for OIE-listed pathogens. Here, we report the first official case of P. marinus detection in native Crassosstrea sp. and in Crassostrea gigas from southern Brazil by PCR followed by sequencing of amplified fragments of the rDNA ITS region. For a better understanding of the epidemiology of P. marinus, we studied the parasite’s phylogenetic intraspecific variability based on its rDNA NTS region by comparisons of our isolates with other isolates from two Mexican regions on the Pacific coast. All Brazilian isolates clustered together with the Mexican isolates. As expected, high similarities were seen between all Brazilian isolates. Additional studies on P. marinus genotyping using new genomic target tools should be conducted for a better understanding of this parasite’s epidemiology.
The objective of this study was to investigate, using path analysis, the genotypic correlations of primary and secondary production components as well as their decomposition into direct and indirect effects on the yield of coffee crops subjected to programed cycle pruning (PCP). Twenty-two Conilon coffe genotypes belonging to the breeding program developed by Incaper were subjected to PCP and 17 morpho-agronomic traits were measured in new branches. The traits plagiotropic branch length and number of plagiotropic leaves were discarded to eliminate collinearity problems. Path analysis was efficient in identifying the traits with greatest influence on yield. The most important traits linked to yield were number of orthotropic branches and orthotropic branch dry matter, while the secondary traits were orthotropic branch diameter, orthotropic internode length, and length of the plagiotropic branch internode. To increase coffee crop yield, producers should select genotypes that produce an intermediate number of orthotropic branches, which have a higher dry matter yield. Subsequently, they should select genotypes with larger orthotropic branch diameters, and among these, those which have shorter orthotropic and plagiotropic internode lengths.
Many studies have explored variability to select cattle with high genetic potential for economic interest traits. Genetic variability is a powerful tool to improve production indexes in cattle, as it also is associated with variations in meat and carcass quality traits. We made a Genome-Wide Association Study of beef cattle of Bos indicus origin, in particular Nelore animals, to identify regions and genes associated with carcass quality, by examining phenotypic and genotypic data from 909 animals. Several genes in associated regions were observed to have above 1% of the portion of explained genetic variance explained: for hot carcass weight, genes LRGUK, TRIM24, SVOPL, TEX37, CA10, OXSR1; for ribeye area, genes TWIST2, SFXN1, CMYA5, CPQ and MRS2; for backfat thickness, genes OR2S2, 5S_rRNA, LOC100299372, LOC523083, LOC532403, LOC613441, SNORA69 and ITGA9; and for marbling, genes EMCN, LNX1, EIF5, SNORA28 and DSC3. The various genomic regions associated with small effects show the complexity of these phenotypes and that they do not depend only on the effects of a few genes to determine their variations.
Pepper has considerable genetic diversity and versatility. Knowledge of the genetic control of traits in peppers is of great importance for breeding programs given the large variety of types, sizes, colors and flavors. To this end, we examined the inheritance of seedling and plant traits in ornamental pepper (Capsicum annuum). The experiment was conducted in a greenhouse in Areia, Paraíba, Brazil. Seven ornamental pepper accessions (C. annuum) belonging to the Federal University of Paraiba’s Germplasm Bank were investigated: UFPB001, UFPB004, UFPB77.3, UFPB099, UFPB134, UFPB137 and UFPB390. Morphoagronomic characterization was performed based on Capsicum descriptors, and 12 quantitative traits were evaluated in seedlings and plants. The data were subjected to variance analysis and subsequent diallel analysis performed according to Hayman's method. The t statistic was used to test the adequacy of the additive-dominance model. The traits seedling height, hypocotyl diameter, cotyledon leaf length, plant height, bifurcation height, leaf length and width and chlorophyll a and b are in agreement with the additive-dominant model. Correlations were positive and significant for seedling height (0.470) and hypocotyl diameter (0.885). Cotyledonary leaf length and width showed negative and significant values of -0.088 and -0.669, respectively. The correlations were positive for the following traits: plant height, stem diameter, first bifurcation height, canopy diameter, leaf length and chlorophyll b, with values ranging from 0.094 to 0.965. Leaf width and chlorophyll a exhibited negative r correlation values. In the genetic parameters estimate, the positive r correlation for most of the traits indicates that the recessive alleles were generally responsible for the increase in these traits. Genetic gains for plant traits in ornamental peppers are possible using breeding programs. The parents UFPB001 and UFPB134 exhibited the highest concentration of favorable alleles for size traits and are indicated for selection for continued improvement programs.