Genetic divergence among Psidium accessions based on single nucleotide polymorphisms developed for Eucalyptus.

The goal of this study was to analyze the genetic divergence among Psidium species accessions based on SNPs developed for Eucalyptus. Fifty-three Psidium accessions, including 47 P. guajava, were genotyped with EUCHIP60K. The dendrogram similarity ranged from 0.58 to 1.00, with a cophenetic value of 0.97. Five groups were identified at dendrogram cut point of 0.7: the first with 44 guava accessions, the second with 1 guava accession, the third with 3 P. guineense accessions, the forth with 2 guava accessions, and the fifth with 3 P. cattleianum accessions. The Bayesian analyses suggested seven subpopulations, with formation of two additional groups with guava accessions. Primers designed with Eucalyptus SNP sequences resulted in reliable Psidium amplicons on 6% polyacrylamide gels. In general, the SNP dendrogram agreed with biological genus structure, since different species were not grouped, indicating that transferability among Myrtaceae genus was possible and reliable.

Fertility restoration locus and cytoplasm types in onion.

The objective of this study was the identification of the cytoplasmic types and the genotyping for the fertility restoration nuclear locus (Ms) in 59 onion accessions, aiming at the selection of 'A' and 'B' lines essential for the obtainment of hybrids. Three markers were used to identify the cytoplasm 5' cob, orfA501, and orf725, and two were used for the Ms locus (AcSKP1 and AcPMS1). The two types of male-sterile cytoplasm ('S' and 'T'), as well as fertile cytoplasm ('N'), and the Ms and ms alleles in both homozygosity and heterozygosity were detected in the 59 genotypes evaluated in the experiment. The frequencies of the 5' cob/orfA501 and orf725 markers, as well as of the markers AcSKP1 and AcPMS1, were close in the onion accessions evaluated in this study. In the Brazilian germplasm, the frequencies of the 'N', 'S', and 'T' cytoplasm were approximately 0.47, 0.28, and 0.25, respectively, whereas the allele frequencies of Ms and ms were 0.52 and 0.48, respectively. The accessions Régia, EHCEB 20146, EHCEB 201427, Alvorada, Serrana, Crioula Mercosul, EHCEB 20142, BRS 367, Rainha, Juporanga, and Alfa SF C-XI have potential for the identification of 'A' and 'B' lines, since they presented mixtures of cytoplasm and different allele frequencies for Ms. All the plants of the accessions EHCEB 20142040/EHCEB 20141040, EHCEB 20142028/EHCEB 20141028, and EHCEB 20112006/EHCEB 20111006 were in the Nmsms and Smsms conditions, and have the potential for 'B' and 'A' lines, respectively, for the CMS-S system. All the plants of the accessions EHCEB 20142027/EHCEB 20141027, EHCEB 20102019/EHCEB 20101019, and Alfa SF 'B'/Alfa SF 'A' were in Nmsms and Tmsms conditions, and have the potential for 'B' and 'A' lines, respectively, for the CMS-T system.

Genetic control and transgressive segregation of zinc, iron, potassium, phosphorus, calcium, and sodium accumulation in cowpea (Vigna unguiculata) seeds.

Cowpea crop, through combining a range of essential minerals with high quality proteins, plays an important role in providing nutritional security to human population living in semi-arid regions. Studies on genetics of biofortification with essential minerals are still quite scarce, and the major objective of the present study was to provide genetic information on development of cowpea cultivars with high seed mineral contents. Genetic parameters heritability and minimum number of genes were estimated for seed accumulation of zinc (Zn), iron (Fe), calcium (Ca), phosphorus (P), potassium (K), and sodium (Na). Generation mean and variance analyses were conducted using contrasting parental lines, F1, F2, and backcross populations derived from IT97K-1042-3 x BRS Tapaihum and IT97K-1042-3 x Canapu crosses. High narrow-sense heritability (h²) values were found for accumulation of Fe (65-86%), P (74-77%), and K (77-88%), whereas moderate h(2) values were observed for accumulation of Ca (41-56%), Zn (51-83%), and Na (50-55%) in seeds. Significant additive genetic effects as well as parental mean effects were detected in both crosses for all minerals, whereas epistasis was important genetic component in Zn content. The minimum number of genes controlling the accumulation of minerals ranged from two (K) to 11 (P). Transgressive segregation was observed in F2 populations of both crosses for all minerals analyzed. The results suggest that, although under either oligogenic or polygenic control, the seed content of these six minerals in cowpea can be improved via standard breeding methods largely used for self-pollinated crops.

Microsatellite markers linked to the locus of the watermelon fruit stripe pattern.

Agronomic performance and external and internal appearance of watermelon (Citrullus lanatus) fruit are important traits that should be taken into consideration during the development of a new cultivar, as well as being the principal identification elements used by the consumer, which are based on the external appearance and quality of the fruit. Externally, the fruit can be characterized in terms of the shape, the color of the lower rind, and the presence of grooves and stripes, the stripes can be classified as clearly defined or diffuse. The objective of this study was to identify microsatellite markers linked to the stripe pattern of watermelon fruit to support watermelon improvement programs, with the selection of this characteristic in the plantlet stage. F1 and F2 populations, result of a cross between the cultivars BRS Opara (clearly defined stripes) and Pérola (diffuse stripes), were phenotyped for their fruit stripe pattern. The CTAB 2X protocol was used for DNA extraction and 116 microsatellite markers were examined in a group of F2 plants that had fruit with well-defined stripes and fruit with diffuse stripes. The microsatellite loci MCPI_05 and MCPI_16 exhibited a linkage to the stripe pattern at a distance of 1.5 and 1.8 cM, respectively, with LOD scores of 39.28 and 38.11, respectively, which were located on chromosome six of the watermelon genome. These markers can be used in marker-assisted selection in watermelon improvement programs, by various research institutions.

Small-angle X-ray scattering and in silico modeling approaches for the accurate functional annotation of an LysR-type transcriptional regulator.

Xylella fastidiosa is a xylem-limited, Gram-negative phytopathogen responsible for economically relevant crop diseases. Its genome was thus sequenced in an effort to characterize and understand its metabolism and pathogenic mechanisms. However, the assignment of the proper functions to the identified open reading frames (ORFs) of this pathogen was impaired due to a lack of sequence similarity in the databases. In the present work, we used small-angle X-ray scattering and in silico modeling approaches to characterize and assign a function to a predicted LysR-type transcriptional regulator in the X. fastidiosa (XfLysRL) genome. XfLysRL was predicted to be a homologue of BenM, which is a transcriptional regulator involved in the degradation pathway of aromatic compounds. Further functional assays confirmed the structural prediction because we observed that XfLysRL interacts with benzoate and cis,cis-muconic acid (also known as 2E,4E-hexa-2,4-dienedioic acid; hereafter named muconate), both of which are co-factors of BenM. In addition, we showed that the XfLysRL protein is differentially expressed during the different stages of X. fastidiosa biofilm formation and planktonic cell growth, which indicates that its expression responds to a cellular signal that is likely related to the aromatic compound degradation pathway. The assignment of the proper function to a protein is a key step toward understanding the cellular metabolic pathways and pathogenic mechanisms. In the context of X. fastidiosa, the characterization of the predicted ORFs may lead to a better understanding of the cellular pathways that are linked to its bacterial pathogenicity.

Extreme thermopower anisotropy and interchain transport in the quasi-one-dimensional metal Li0.9Mo6O17.

Thermopower and electrical resistivity measurements transverse to the conducting chains of the quasi-one-dimensional metal Li0.9Mo6O17 are reported in the temperature range 5≤T≤500 K. For T≥400 K the interchain transport is determined by thermal excitation of charge carriers from a valence band ∼0.14 eV below the Fermi level, giving rise to a large, p-type thermopower that coincides with a small, n-type thermopower along the chains. This dichotomy-semiconductorlike in one direction and metallic in a mutually perpendicular direction-gives rise to substantial transverse thermoelectric effects and a transverse thermoelectric figure of merit among the largest known for a single compound.

Education and severe maternal outcomes in developing countries: a multicountry cross-sectional survey.

OBJECTIVE: To assess the relationship between education and severe maternal outcomes among women delivering in healthcare facilities. DESIGN: Cross-sectional study. SETTING: Twenty-nine countries in Africa, Asia, Latin America, and the Middle East. POPULATION: Pregnant women admitted to 359 facilities during a period of 2-4 months of data collection between 2010 and 2011. METHODS: Data were obtained from hospital records. Stratification was based on the Human Development Index (HDI) values of the participating countries. Multivariable logistic regression analyses were conducted to assess the association between maternal morbidity and education, categorised in quartiles based on the years of formal education by country. Coverage of key interventions was assessed. MAIN OUTCOME MEASURES: Severe maternal outcomes (near misses and death). RESULTS: A significant association between low education and severe maternal outcomes (adjusted odds ratio, aOR, 2.07; 95% confidence interval, 95% CI, 1.46-2.95), maternal near miss (aOR 1.80; 95% CI 1.25-2.57), and maternal death (aOR 5.62; 95% CI 3.45-9.16) was observed. This relationship persisted in countries with medium HDIs (aOR 2.36; 95% CI 1.33-4.17) and low HDIs (aOR 2.65; 95% CI 1.54-2.57). Less educated women also had increased odds of presenting to the hospital in a severe condition (i.e. with organ dysfunction on arrival or within 24 hours: aOR 2.06; 95% CI 1.36-3.10). The probability that a woman received magnesium sulphate for eclampsia or had a caesarean section significantly increased as education level increased (P < 0.05). CONCLUSIONS: Women with lower levels of education are at greater risk for severe maternal outcomes, even after adjustment for key confounding factors. This is particularly true for women in countries that have poorer markers of social and economic development.

Characterization of the human dynein light chain Rp3 and its use as a non-viral gene delivery vector.

Dynein light chains mediate the interaction between the cargo and the dynein motor complex during retrograde microtubule-mediated transport in eukaryotic cells. In this study, we expressed and characterized the recombinant human dynein light chain Rp3 and developed a modified variant harboring an N-terminal DNA-binding domain (Rp3-Db). Our approach aimed to explore the retrograde cell machinery based on dynein to enhance plasmid DNA (pDNA) traffic along the cytosol toward the nucleus. In the context of non-viral gene delivery, Rp3-Db is expected to simultaneously interact with DNA and dynein, thereby enabling a more rapid and efficient transport of the genetic material across the cytoplasm. We successfully purified recombinant Rp3 and obtained a low-resolution structural model using small-angle X-ray scattering. Additionally, we observed that Rp3 is a homodimer under reducing conditions and remains stable over a broad pH range. The ability of Rp3 to interact with the dynein intermediate chain in vitro was also observed, indicating that the recombinant Rp3 is correctly folded and functional. Finally, Rp3-Db was successfully expressed and purified and exhibited the ability to interact with pDNA and mediate the transfection of cultured HeLa cells. Rp3-Db was also capable of interacting in vitro with dynein intermediate chains, indicating that the addition of the N-terminal DNA-binding domain does not compromise its function. The transfection level observed for Rp3-Db is far superior than that reported for protamine and is comparable to that of the cationic lipid Lipofectamine™. This report presents an initial characterization of a non-viral delivery vector based on the dynein light chain Rp3 and demonstrates the potential use of modified human light chains as gene delivery vectors.

Chromatography of Solanum habrochaites extracts with the first record of the docosanoate, hexadecanoate and octadecanoate ethyls in this plant and in Solanaceae.

The increasing need for sustainable alternatives to synthetic insecticides has driven the analysis of extracts from Solanum habrochaites, a wild tomato, through fractionated column chromatography. Potential bioactive compounds for pest management, a clean and promising biotechnological solution, have been reported from this plant. The objective is to provide detailed gas chromatography data, including peaks, structural formulas, and retention indices for the extracts of S. habrochaites aerial parts. Column chromatographic analysis was conducted with five fractions (F1, F2, F5, F3, and F4) of S. habrochaites extracts. Long-chain hydrocarbons such as hexadecanoic acid and docosano were identified in the F1 fraction; fatty acid esters, including hexadecanoate and octadecenoate ethyls in the F2 and methyl ketones, with tridecan-2-one as the major component in the F5, while no identifiable compounds were disclosed in the F3 and F4 fractions. The column chromatography provided valuable insights into compounds in the F1, F2, and F5 fractions of S. habrochaites extracts, highlighting fatty acid esters, long-chain hydrocarbons, and methyl ketones. The bioactive compounds, from extracts of this plant, including the first record of the docosanoate, hexadecanoate and octadecanoate ethyls in S. habrochaites and Solanaceae, reinforces their promising biological application in different areas of science.

Carotenoid and lipid production by the autotrophic microalga Chlorella protothecoides under nutritional, salinity, and luminosity stress conditions.

Today microalgae represent a viable alternative source for high-value products. The specie Chlorella protothecoides (Cp), heterotrophically grown, has been widely studied and provides a high amount of lutein and fatty acids (FA) and has a good profile for biodiesel production. This work studies carotenoid and FA production by autotrophic grown Cp. Cp was grown until the medium's nitrogen was depleted, then diluted in NaCl solution, resulting in nutritional, luminosity, and salinity stresses. Different NaCl concentrations were tested (10, 20, 30 g/L) at two different dilutions. After dilution, a color shifting from green to orange-red was noticed, showing carotenoid production. The best production of both carotenoids and FA was attained with a 20 g/L NaCl solution. The total carotenoid content was 0.8 % w/w (canthaxanthin (23.3 %), echinenone (14.7 %), free astaxanthin (7.1 %), and lutein/zeaxanthin (4.1 %)). Furthermore, the total lipid content reached 43.4 % w/w, with a FA composition of C18:1 (33.64 %), C16:0 (23.30 %), C18:2 (11.53 %), and less than 12 % of C18:3, which is needed to fulfill the biodiesel quality specifications (EN 14214).

Land application of municipal landfill leachate: fate of ions and ammonia volatilization.

Landfill leachates are pollutants rich in ammoniacal N, Na, and K, but land application potentially offers an alternative for recycling these leachate nutrients. We applied landfill leachate corresponding to 0, 110, 220, 330, and 440 kg ha of total N, divided in three applications (July, August, and October 2008), onto the surface of an acidic (pH 5.5-6.0) clay (79% clay) Ultisol and monitored NH volatilization just after applications and microbiological (0-10 cm) and chemical attributes (0-60-cm soil depth) in August 2008, January 2009, and May 2009. Ammonium (up to 30 mg kg), NO (up to 160 mg kg), Na, K (up to 1.1 cmol kg each), and electrical conductivity (up to 1 dS m) increased transiently in soil following applications. Despite >90% of the total leachate N being ammoniacal, NO predominated in the first soil sampling, 14 d after the second application, suggesting fast nitrification, but it decreased in the soil profile thereafter. From 5 to 25% of the total applied N volatilized as NH, with maximum losses within the first 3 d. Applications inhibited (50%) the relative nitrification rate and increased (50%) hot-water-soluble carbohydrates in the soil at the highest rate. No effects were observed on soil microbial biomass C (114-205 mg kg) and activity (5-8 mg CO-C kg d) or on corn grain yields (6349-7233 kg ha). Controlled land application seems to be a viable alternative for landfill leachate management, but NO leaching, NH volatilization, and accumulation of salinizing ions must be monitored in the long term to prevent environmental degradation.

Breeding biofortified cowpea lines for semi-arid tropical areas by combining higher seed protein and mineral levels.

One strategy to mitigate human malnutrition in semi-arid areas is to increase the protein and mineral content of cowpea cultivars. Total seed protein, potassium, calcium, iron, zinc, and sodium contents were quantified in elite cowpea lines, with the aim to develop cultivars that had improved levels of these nutrients. Eighty-seven F6 lines derived from 6 crosses were evaluated under rain-fed conditions in Petrolina, Brazil. Seed protein and mineral content were quantified by the micro-Kjeldhal method and in an atomic absorption spectrophotometer, respectively. Statistical analyses were estimated for all traits, including grain yield. Significant differences were observed for all characteristics. Seed protein content ranged from 22.5 to 34.1%, potassium levels ranged from 20,200 to 27,000 ppm, and calcium levels ranged from 410 to 6260 ppm. Iron content ranged from 36.5 to 137 ppm, while zinc content ranged from 36 to 58 ppm and sodium content ranged from 29.2 to 88 ppm. Simple correlation coefficient values indicated that selection for high protein and mineral content does not affect grain yield. These results demonstrate that it is feasible to obtain new biofortified cowpea cultivars by combining higher levels of protein and essential minerals.

Allelic database and divergence among Psidium accessions by using microsatellite markers.

This study aimed to investigate the genetic variability among guava accessions and wild Psidium species of the Embrapa Semiárido germplasm collection by using microsatellite loci to guide genetic resources and breeding programs, emphasizing crosses between guava and other Psidium species. DNA was extracted using the 2X CTAB method, and polymerase chain reaction products were analyzed on 6% denatured polyacrylamide gels stained with silver nitrate. The unweighted pair-group method using arithmetic average dendrogram generated from the distance matrix of the Jaccard coefficient for 183 alleles of 13 microsatellite loci was used for visualization of genetic similarity. The number of base pairs was estimated using inverse mobility method based on the regression of known-size products. Analysis of molecular variance was performed using total decomposition between and within guava accessions. The accessions showed similarity from 0.75 to 1.00, with the dendrogram presenting cophenetic value of 0.85. Five groups were observed: the first included guava accessions; the second, P. guineense accessions; the third, one accession of P. friedrichsthalianum; and the last 2 groups, P. cattleianum. The genetic similarity among P. guineense and some guava accessions were above 80%, suggesting greater possibility to obtain interspecies hybrids between these 2 species. The genetic variability between the accessions was considered to be high (ΦST = 0.238), indicating that guava genetic variability is not uniformly distributed among the 9 Brazilian states from where the accession were obtained. Obtaining a greater number of accessions by Brazilian states is recommended in order to have greater diversity among the species.

Genetic variability of watermelon accessions based on microsatellite markers.

We analyzed the genetic variability of 40 watermelon accessions collected from 8 regions of Northeastern Brazil using microsatellite markers, in order to suggest strategies of conservation and utilization of genetic variability in this species. These accessions are not commercial cultivars. They were sampled in areas of traditional farmers that usually keep their own seeds for future plantings year after year. An UPGMA dendrogram was generated from a distance matrix of the Jaccard coefficient, based on 41 alleles of 13 microsatellite loci. Analysis of molecular variance was made by partitioning between and within geographical regions. The similarity coefficient between accessions ranged from 37 to 96%; the dendrogram gave a co-phenetic value of 0.80. The among population genetic variability was high ( (^)ϕST = 0.319). Specific clusters of accessions sampled in 3 regions of Maranhão were observed while the other 5 regions did not presented specific clusters by regions. We conclude that watermelon genetic variability is not uniformly dispersed in the regions analyzed, indicating that geographical barriers or edaphoclimatic conditions have limited open mating. We suggest sampling a greater number of populations, so regional species diversity will be better represented and preserved in the germplasm bank.

Giant Nernst effect and bipolarity in the quasi-one-dimensional metal Li0.9Mo6O17.

The Nernst coefficient for the quasi-one-dimensional metal, Li{0.9}Mo{6}O{17}, is found to be among the largest known for metals (ν≃500 µV/KT at T∼20 K), and is enhanced in a broad range of temperature by orders of magnitude over the value expected from Boltzmann theory for carrier diffusion. A comparatively small Seebeck coefficient implies that Li{0.9}Mo{6}O{17} is bipolar with large, partial Seebeck coefficients of opposite sign. A very large thermomagnetic figure of merit, ZT∼0.5, is found at high field in the range T≈35-50 K.

Individual and contextual determinants of the duration of diarrhoeal episodes in preschool children: a longitudinal study in an urban setting.

This study investigated individual and contextual factors associated with the duration of diarrhoeal episodes in 693 young children living in a large Brazilian city who were followed-up for at least 3 months. The outcome is analysed as a continuous variable, by means of a hierarchical conceptual model organizing the factors in meaningful blocks. A total of 2397 episodes were recorded (median duration 2 days, interquartile range 1-3 days). Low percentage of households connected to the sewerage system in the neighbourhood, low family purchasing power, high agglomeration, mother aged <19 years, low zinc content in child's diet, and episode severity were significantly associated with longer duration (0·26-0·69 days more). Purchasing power effect was largely mediated by environmental conditions, characteristics of the child, and hygienic behaviour. Environmental conditions acted as a possible effect modifier, enhancing the effect on duration of diarrhoea of the child not having being vaccinated against measles or breastfed for >6 months.

Mapping of AFLP loci linked to tolerance to cowpea golden mosaic virus.

AFLP markers combined with the bulk segregant analysis methodology was used for the identification of molecular markers associated with the cowpea golden mosaic virus (CGMV) resistance gene in 286 F(2) cowpea plants derived from the cross IT97K-499-35 x Canapu T16. Segregation data in the F(2) population demonstrated that tolerance to CGMV is controlled by a single dominant gene. Among the 196 combinations of AFLP primers tested, which generated approximately 3800 amplicons, three markers linked to the CGMV resistance gene were identified: E.AAC/M.CCC(515) at 4.3 cM, E.AGG/M.CTT(280) at 14.2 cM and E.AAA/M.CAG(352) at 16.8 cM, with 50.4, 24.4, and 28.7 LOD scores, respectively; the former two markers flank the CGMV loci. These markers could be used for the development of 'sequence characterized amplified region' type markers or for greater saturation of this region, to increase the precision of assisted selection for the development of cowpea strains tolerant to CGMV.

Allelic database and accession divergence of a Brazilian mango collection based on microsatellite markers.

Allelic patterns and genetic distances were examined in a collection of 103 foreign and Brazilian mango (Mangifera indica) accessions in order to develop a reference database to support cultivar protection and breeding programs. An UPGMA dendrogram was generated using Jaccard's coefficients from a distance matrix based on 50 alleles of 12 microsatellite loci. The base pair number was estimated by the method of inverse mobility. The cophenetic correlation was 0.8. The accessions had a coefficient of similarity from 30 to 100%, which reflects high genetic variability. Three groups were observed in the UPGMA dendrogram; the first group was formed predominantly by foreign accessions, the second group was formed by Brazilian accessions, and the Dashehari accession was isolated from the others. The 50 microsatellite alleles did not separate all 103 accessions, indicating that there are duplicates in this mango collection. These 12 microsatellites need to be validated in order to establish a reliable set to identify mango cultivars.

Comparison of efficiency of distance measurement methodologies in mango (Mangifera indica) progenies based on physicochemical descriptors.

We investigated seven distance measures in a set of observations of physicochemical variables of mango (Mangifera indica) submitted to multivariate analyses (distance, projection and grouping). To estimate the distance measurements, five mango progeny (total of 25 genotypes) were analyzed, using six fruit physicochemical descriptors (fruit weight, equatorial diameter, longitudinal diameter, total soluble solids in °Brix, total titratable acidity, and pH). The distance measurements were compared by the Spearman correlation test, projection in two-dimensional space and grouping efficiency. The Spearman correlation coefficients between the seven distance measurements were, except for the Mahalanobis' generalized distance (0.41 ≤ rs ≤ 0.63), high and significant (rs ≥ 0.91; P < 0.001). Regardless of the origin of the distance matrix, the unweighted pair group method with arithmetic mean grouping method proved to be the most adequate. The various distance measurements and grouping methods gave different values for distortion (-116.5 ≤ D ≤ 74.5), cophenetic correlation (0.26 ≤ rc ≤ 0.76) and stress (-1.9 ≤ S ≤ 58.9). Choice of distance measurement and analysis methods influence the.

Application of a simulated annealing optimization to a physically based erosion model.

A major risk concerning the calibration of physically based erosion models has been partly attributable to the lack of robust optimization tools. This paper presents the essential concepts and application to optimize the erosion parameters of an erosion model using data collected in an experimental basin, with a global optimization method known as simulated annealing (SA) which is suitable for solving optimization problems of large scales. The physically based erosion model that was chosen to be optimized here is the Watershed Erosion Simulation Program (WESP), which was developed for small basins to generate the hydrograph and the respective sedigraph. The field data were collected in an experimental basin located in a semiarid region of Brazil. On the basis of these results, the following erosion parameters were optimized: the soil moisture-tension parameter (N(s)) that depends also on the initial moisture content, the channel erosion parameter (a), the soil detachability factor (K(R)), and the sediment entrainment parameter by rainfall impact (K(I)), whose values could serve as initial estimates for semiarid regions within northeastern Brazil.