American Genotype Research Articles

The Role of Melatonin in Improving The Vegetative Growth Characteristics of Four Genotypes of Faba Bean (Vicia faba L.)

A field study was conducted at a research station in Al-Hamidiyah, which is affiliated to the College of Agriculture - University of Anbar, during winter 2020-2021. It aims to study the effect of four concentrations of the growth regulator melatonin on the vegetative growth traits of four genotypes of faba bean. A split –plot arrangement in randomaized complete block design RCBD, in three replications, was used. The concentrations of the growth regulator occupied the main plots (0, 5, 10 and 15) mg.l-1. While the American (Sakis), Dutch (Aquadulce), Italian (Ackerbhone) and Turkish (Aquadlge) genotypes occupied the sub plots. The most important results were the following: The American genotype superiority in most growth traits gave the height of plant is 96.94 cm, branches number in plant is 10.08, leaf area is 4770 cm2. plant-1, dry weight of plant is 184.71 g, chlorophyll content in the leaves is 48.21 spad, and the length of the pod is 19.63 cm. As for the Italian variety, it gave the lowest period from planting to the beginning of flowering, which was 59.42 day. As for the Turkish genotype record, the longest period from planting to beginning of flowering 64.57day. Spraying with the growth regulator melatonin led to the emergence of significant differences between all the traits. The concentration 15 mg.l-1 of melatonin gave a highest mean for each: plant height is 78.23 cm, branches number is 8.50, leaf area is 3840 cm2. Plant-1, dry weight is 177.63 g, chlorophyll content in the leaves is 44.02 spad, and the length of the pod is 18.15 cm. There was a significant overlap between American genotype with concentration 15 mg.l-1 in each of the leaf area, dry weight of the plant, and chlorophyll content of leaves. The overlap was significant between American genotype with concentration 10 mg. l-1 in plant height.

Characterization of bitter compounds in native and hybrid American hazelnuts

The main objective of this study was to identify compounds that contribute to the bitter taste attributes of American hazelnuts (C. americana) and derived hybrids. Sensory-guided Prep-LC fractionation analysis selected four compounds as bitter that were further identified by MS and NMR as carpinontriol B, 2-(3-hydroxy-2-oxoindolin-3-yl)acetic acid 3-O-6′-galactopyranosyl-2″-(2″oxoindolin-3″yl) acetate, giffonin-2-O-[(α-d-glucopyranosyl)-6′-O-(3-hydroxy-3-methylglutaric acid) and Afzelin, termed compounds 1–4, respectively. The concentrations of compounds 1, 2, 3, and 4 were determined across 88 American hybrid hazelnut genotypes and reported to be present at levels above their bitter threshold values in 94, 75, 25, and 0% of the samples, respectively. Moreover, the concentrations of compounds 1 and 3 were significantly higher for nuts dehusked prior to drying during post-harvest handling, which is expected to result in a higher perceived bitter intensity.

Phylogenetic and evolutionary analysis of dengue virus serotypes circulating at the Colombian-Venezuelan border during 2015-2016 and 2018-2019.

Dengue is an endemic disease in Colombia. Norte de Santander is a region on the border of Colombia and Venezuela and has reported the co-circulation and simultaneous co-infection of different serotypes of the dengue virus (DENV). This study aimed to conduct a phylogenetic analysis on the origin and genetic diversity of DENV strains circulating in this bordering region. Serum samples were collected from patients who were clinically diagnosed with febrile syndrome associated with dengue during two periods. These samples were tested for DENV and serotyping was performed using reverse transcriptase-polymerase chain reaction. Subsequently, positive samples were amplified and the envelope protein gene of DENV was sequenced. Phylogenetic and phylogeographic analyses were performed using the sequences obtained. Basic local alignment search tool analysis confirmed that six and eight sequences belonged to DENV-1 and DENV-2, respectively. The phylogenetic analysis of DENV-1 showed that the sequences belonged to genotype V and clade I; they formed two groups: in the first group, two sequences showed a close phylogenetic relationship with strains from Ecuador and Panama, whereas the other four sequences were grouped with strains from Venezuela and Colombia. In the case of DENV-2, the analysis revealed that the sequences belonged to the Asian-American genotype and clade III. Furthermore, they formed two groups; in the first group, three sequences were grouped with strains from Colombia and Venezuela, whereas the other five were grouped with strains from Venezuela, Colombia and Honduras. This phylogenetic analysis suggests that the geographical proximity between Colombia and Venezuela is favourable for the export and import of different strains among serotypes or clades of the same DENV serotype, which could favour the spread of new outbreaks caused by new strains or genetic variants of this arbovirus. Therefore, this information highlights the importance of monitoring the transmission of DENV at border regions.

Diversity and origins of Butomus umbellatus (flowering rush) invasion in North America

Flowering rush (Butomus umbellatus) is an invasive aquatic plant in northern USA and southern Canada. To better understand the pattern of invasion in North America and implications for management, we investigated genetic diversity and population structure of the more recent western North American invasion and compared it to the earlier eastern North America invasion using 80 variable AFLP loci. We found six invasive genotypes, indicating multiple founding events, with primarily monotypic populations indicating clonal reproduction. The genetic makeup and ploidy of the western North America populations is distinct from the earlier eastern North American invasion, with different genotypes and ploidy levels dominating different regions. Flowering rush is under consideration for classical biological control, and initial studies show that some genotypes are resistant or tolerant to a proposed plant pathogen. To inform biological control development and direct foreign exploration, we compared genetic data with Eurasian native samples and found an exact genetic match for the common western North American genotype in the Netherlands, and propose best estimates of origins for the other invasive genotypes. The different genetic makeup of the invasion at regional scales, and their differing phenotypes in terms of reproductive mode and susceptibility to highly host-specific biological control supports the investigation of specialized management programs for different portions of the North American invasion.

Response Growth and Yield Traits of Faba Bean Genotype to Foliar Feeding with Triplex Amino Biostimulator

A field experiment was carried out in the winter season 2019-2020, in the Nuaimiya region of Fallujah city – Al -Anbar Governorate. The aim of the experiment was to study the response of growth and yield traits of faba bean to foliar feeding with Triplex amino biostimulator. The experiment was applied by using a randomized complete block design (RCBD) according to the arrangement of the split-plot with three replicates. The main plots included three genotypes from the remnants (American, Dutch and Italian), While the sub plots included four concentrations of Triplex amino biostimulator (0, 2.5, 5 and 7.5) g L−1. The Dutch genotype recorded the highest average for each of the number of branches in the plant (8. 84branch.plant−1), leaf area (3289.2 cm2). Plant−1, number of pods per plant (19.25 pods. Plant−1), number of seeds per pod (4.56 seed.pod−1) and seed yield (4.263t.h−1), While the American genotype gave the highest average for plant height (106.70 cm) and 100 seed weight (114.5 g.) The biostimulant significantly effect on all growth and yield traits, the concentration 7.5 g. L−1 gave the highest average for each of Plant height (113.29 cm), number of branches per plant (9.88 branch. plant−1 ), leaf area(3637.9 cm2). Plant−1, number of pods per plant (22.06) pods, number of seeds per pod (4.48 seed.pod−1, weight of 100 seeds (125.2g) and seed yield (4,342 t.h−1). The interaction between the Dutch genotype and concentration 7.5 g. L−1 of the bio stimulant was given the highest average for the number of branches per plant, leaf area, number of pods per plant, and number of seeds per pod.

Detection of DENV-2 and Insect-Specific Flaviviruses in Mosquitoes Collected From Jeddah, Saudi Arabia.

BackgroundMosquito-borne diseases are rapidly spreading due to increasing international travel and trade. Routine mosquito surveillance and screening for mosquito-borne pathogens can be early indicators for local disease transmission and outbreaks. However, arbovirus detection in mosquito vectors has rarely been reported in Saudi Arabia.MethodsA total of 769,541 Aedes and Culex mosquitoes were collected by Black Hole traps during routine mosquito surveillance in the first half of 2016. Culex. quinquefasciatus and Ae. aegypti were the most prevalent species observed. Twenty-five and 24 randomly selected pools of Ae. aegypti and Cx. quinquefasciatus, respectively, were screened for arboviruses by RT-PCR.ResultsDengue 2 (DENV-2) and four strains of insect-specific flaviviruses, including one of cell-fusing agent virus (CFAV) and three of Phlebotomus-associated flavivirus (PAFV) were detected in pools of Ae. aegypti. We also detected 10 strains of Culex flavivirus (CxFV) in pools of Cx. quinquefasciatus. Phylogenetic analysis using whole genome sequences placed the DENV strain into the cosmopolitan 1 sub-DENV-2 genotype, and the CxFVs into the African/Caribbean/Latin American genotype. These analyses also showed that the DENV-2 strain detected in the present study was closely related to strains detected in China in 2014 and in Japan in 2018, which suggests frequent movement of DENV-2 strains among these countries. Furthermore, the phylogenetic analysis suggested at least five introductions of DENV-2 into Saudi Arabia from 2014 through 2018, most probably from India.ConclusionsTo our knowledge, this study reports the first detection of four arboviruses DENV, CFAV, PAFV, and CxFV in mosquitoes in Saudi Arabia, which shows that they are co-circulating in Jeddah. Our findings show a need for widespread mosquito-based arbovirus surveillance programs in Saudi Arabia, which will improve our understanding of the transmission dynamics of the mosquito-borne arboviruses within the country and help early predict and mitigate the risk of human infections and outbreaks.

Commercial PRRS Modified-Live Virus Vaccines.

Porcine reproductive and respiratory syndrome (PRRS) virus (PRRSV) presents one of the challenging viral pathogens in the global pork industry. PRRS is characterized by two distinct clinical presentations; reproductive failure in breeding animals (gilts, sows, and boars), and respiratory disease in growing pigs. PRRSV is further divided into two species: PRRSV-1 (formerly known as the European genotype 1) and PRRSV-2 (formerly known as the North American genotype 2). A PRRSV-2 modified-live virus (MLV) vaccine was first introduced in North America in 1994, and, six years later, a PRRSV-1 MLV vaccine was also introduced in Europe. Since then, MLV vaccination is the principal strategy used to control PRRSV infection. Despite the fact that MLV vaccines have shown some efficacy, they were problematic as the efficacy of vaccine was often unpredictable and depended highly on the field virus. This paper focused on the efficacy of commercially available MLV vaccines at a global level based on respiratory disease in growing pigs, and maternal and paternal reproductive failure in breeding animals.

Wild relatives and interspecific hybrids of potato as source materials in breeding for resistance to golden nematode

Background. Predominant use of the H1 and Gro1-4 genes of resistance to golden nematode (PGN) in potato breeding requires widening the gene pool of resistance to this pathogen.Materials and methods. Thirty-four genotypes of wild potatoes from North and South Americas, 14 interspecific hybrids, and 10 Russian potato cultivars were studied for PGN resistance. Screening for resistance to PGN pathotype Ro1 and molecular screening for the presence of H1 and Gro1-4 gene markers were performed. Amplification products of the Gro1-4 gene marker were sequenced.Results. Only seven among the studied 34 potato genotypes (two of S. brachystotrichum (Bitt.) Rydb., four of S. lesteri Hawkes et Hjerting, and one of S. kurtzianum Bitt. et Wittm.) were susceptible to PGN, while the rest demonstrated high or medium resistance. Molecular screening for the presence of H1 and Gro1-4 gene markers allowed us to identify Gro1-4 in 13 South American genotypes of S. alandiae Cárd., S. × doddsii Corr., S. kurtzianum, S. leptophyes Bitt., and S. yungasense Hawkes. The remaining 14 genotypes may supposedly contain resistance genes non-identical to H1 or Gro1-4. Hybrids of S. tuberosum L. with medium-resistant wild accessions of S. kurtzianum, S. leptophyes, S. sparsipilum (Bitt.) Juz. et Buk., S. alandiae, and S. × doddsii inherited PGN resistance determined either by the Gro1-4 gene or genes non-identical to H1 or Gro1-4. Sequencing a fragment of the Gro1-4 gene showed that changes in the structure of this fragment in orthologous genes did not affect the feature of resistance to PGN pathotype Ro1.Conclusion. For the first time, sources of resistance to PGN were found among the North American species S. brachystotrichum (k-23201) and S. lesteri (k-24475). Among the wild South American Solanum spp., sources of resistance determined by genes different from H1 or Gro1-4 were identified. Resistant interspecific hybrids can serve as donors of the Gro1-4 resistance gene or new resistance genes.

Genetic variation for tolerance to the downy mildew pathogen Peronospora variabilis in genetic resources of quinoa (Chenopodium quinoa)

BackgroundQuinoa (Chenopodium quinoa Willd.) is an ancient grain crop that is tolerant to abiotic stress and has favorable nutritional properties. Downy mildew is the main disease of quinoa and is caused by infections of the biotrophic oomycete Peronospora variabilis Gaüm. Since the disease causes major yield losses, identifying sources of downy mildew tolerance in genetic resources and understanding its genetic basis are important goals in quinoa breeding.ResultsWe infected 132 South American genotypes, three Danish cultivars and the weedy relative C. album with a single isolate of P. variabilis under greenhouse conditions and observed a large variation in disease traits like severity of infection, which ranged from 5 to 83%. Linear mixed models revealed a significant effect of genotypes on disease traits with high heritabilities (0.72 to 0.81). Factors like altitude at site of origin or seed saponin content did not correlate with mildew tolerance, but stomatal width was weakly correlated with severity of infection. Despite the strong genotypic effects on mildew tolerance, genome-wide association mapping with 88 genotypes failed to identify significant marker-trait associations indicating a polygenic architecture of mildew tolerance.ConclusionsThe strong genetic effects on mildew tolerance allow to identify genetic resources, which are valuable sources of resistance in future quinoa breeding.

The complete chloroplast genome sequence of American elm (Ulmus americana) and comparative genomics of related species

American elm, Ulmus americana L., was widely cultivated in the USA and Canada as a landscape tree. Despite its importance in landscaping and horticulture, its genome is poorly characterized. We assembled the chloroplast genomes of two American elm genotypes (RV16 and Am. 57845); to our knowledge, this is the first description of sequencing and assembly of this species. The complete chloroplast genome of U. americana ranged from 158,935 to 158,993 bp and it contains 127 genes, namely 85 protein-coding genes, 34 tRNA genes, and 8 rRNA genes. Between the two American elm chloroplasts we sequenced, we identified 240 high-quality sequence variants (SNPs and indels). To evaluate the phylogeny of American elm, we compared the chloroplast genomes of the two American elms with seven Asian elm species and twelve other chloroplast genomes available through the NCBI database. As expected, Ulmus was closely related to Morus and Cannabis, as all three genera are assigned to the Urticales. We clarified the timing of the divergence of American elm from the available Asian elms, the divergence within these Asian elms, and all the species’ relative ages. Comparison of the chloroplasts of American elm with the available Asian elms revealed that trnH was absent from American elm but not most Asian elms; conversely, petB, petD, psbL, trnK, and rps16 are present in the American elm but absent from all Asian elms analyzed. ycf15 was present in both American and Asian elms but absent from members of closely related genera. The complete chloroplast genome of U. americana will provide useful genetic resources for characterizing the genetic diversity of U. americana and potentially help to conserve natural populations of American elm.

Phenotypic and molecular diversity of wheat species (Triticum spp.) in relation to plant height and heading time

Plant height and heading time are important agronomic traits that significantly contribute to the improvement of wheat adaptability and yield. The aim of this study was to evaluate the level of phenotypic variability of these two traits in a collection of wheat species originating from 20 countries, to analyse its molecular diversity based on the microsatellite loci associated with the previously mapped quantitative trait loci, and to estimate potential of microsatellites to detect polymorphism in different wheat species and reveal allelic patterns in relation to the geographical origin. The significant differences in plant height and heading time among different wheat groups were observed, while the differences in means among three different growing seasons were significant only for heading time. The principal coordinate analysis distinguished wheat genotypes by their origin and ploidy level. Wheat varieties from America, South and Southeast Europe, and West and Central Europe had the highest molecular diversity, as was evidenced by the higher number of alleles, number of group-specific alleles, Shannon's information index and gene diversity. The Nei?s genetic identity indicated genetic similarity of geographically distinct groups, such as South and Southeast Europe and Russian (0.901) and South and Southeast Europe and American genotypes (0.638). The studied collection with high observed level of both phenotypic and molecular diversity for plant height and heading time may be a valuable source of variation for wheat breeders to fine adjust these traits to achieve better agronomic performance in certain local environments.

Molecular characterisation of porcine reproductive and respiratory syndrome virus from pigs in Kerala.

Porcine reproductive and respiratory syndrome (PRRS) caused by an arterivirus is characterised by reproductive disorders in sows, and post-weaning pneumonia and growth reduction in piglets. Though the virus has been detected in Kerala, no systematic study has been carried out to ascertain its genotype and molecular epidemiology. In the present study, 7 PRRS virus (PRRSV) positive samples collected from incidences of PRRS in Kerala during 2017-2019 were subjected to ORF5, ORF7 and Nsp2 gene based reverse transcription polymerase chain reaction and the specific amplicons generated were sequenced. On BLAST analysis it was revealed that all the sequences were of genotype 2 (North American genotype). Phylogenetic analysis of ORF5 sequences, grouped them under subgenotype 4 with close clustering with other isolates from Kerala, Mizoram and Assam. Nsp2 gene sequence based phylogenetic analysis grouped the isolates under subgenotype 3 with similarities to isolates from Mizoram. Phylogenetic analysis based on ORF7, clustered the isolates under study with PRRSV isolates from Mizoram and Meghalaya. In Nsp2 sequences, a 30 amino acid discontinuous deletion was observed. On analysis of amino acid sequences of ORF5 of Kerala isolates and those from India, it was seen that the Kerala isolates showed closer similarity to PRRSV isolates from Assam than to the other Indian isolates. The study reveals that PRRSV strains prevalent in Kerala share close relationship with other PRRSV isolates in India. This may be due to spread of the virus from these regions to Kerala due to animal movement. Concerted efforts should be undertaken to check unauthorized animal movement to control spread of this economically important disease.

Geographic Distribution of Ehrlichia canis TRP Genotypes in Brazil

Tandem repeat proteins (TRPs) are major immunoreactive proteins of Ehrlichia canis, which have been used in the serological diagnosis of different genotypes of the microorganism. TRP19 is preserved among different E. canis isolates expressed on both reticulate and dense-core cells and observed in the extracellular matrix or associated with the morula membrane. TRP36 is differentially expressed only on the surface of the dense-core form of the bacterium and exhibits more divergence among isolates. The aim of this study was to evaluate the distribution of the American (USTRP36), Brazilian (BrTRP36) and Costa Rican (CRTRP36) genotypes of E. canis in Brazil, using ELISA assays. Serum samples of 814 dogs from 49 municipalities from all over Brazil were analyzed. Our results showed that 34% of the samples were reactive to the USTRP36 genotype and 32.6% to the BrTRP36 genotype. The two genotypes appeared to occur equally throughout Brazil, although the frequency of seropositivity was lower in the south than in the country’s other regions. Dogs that reacted to at least one of the synthetic peptides (TRP19 and TRP36) were 456 (56%). A few dogs (n = 5; 0.61%) reactive to the E. canis TRP36 genotype (CRTRP36) were also detected in the northeast and southern regions. We concluded that the American and Brazilian genotypes of E. canis are distributed evenly in Brazil, especially in the tropical region, while the temperate region in the south presented the lowest prevalence rates. This study offers the first report of dogs seropositive for the Costa Rican genotype in Brazil.

Yellow fever transmission in non-human primates, Bahia, Northeastern Brazil.

Yellow fever virus (YFV) causes a clinical syndrome of acute hemorrhagic hepatitis. YFV transmission involves non-human primates (NHP), mosquitoes and humans. By late 2016, Brazil experienced the largest YFV outbreak of the last 100 years, with 2050 human confirmed cases, with 681 cases ending in death and 764 confirmed epizootic cases in NHP. Among affected areas, Bahia state in Northeastern was the only region with no autochthonous human cases. By using next generation sequence approach, we investigated the molecular epidemiology of YFV in NHP in Bahia and discuss what factors might have prevented human cases. We investigated 47 YFV positive tissue samples from NHP cases to generate 8 novel YFV genomes. ML phylogenetic tree reconstructions and automated subtyping tools placed the newly generated genomes within the South American genotype I (SA I). Our analysis revealed that the YFV genomes from Bahia formed two distinct well-supported phylogenetic clusters that emerged most likely of an introduction from Minas Gerais and Espírito Santo states. Vegetation coverage analysis performed shows predominantly low to medium vegetation coverage in Bahia state. Together, our findings support the hypothesis of two independent YFV SA-I introductions. We also highlighted the effectiveness of the actions taken by epidemiological surveillance team of the state to prevented human cases.

Abstract B073: Estimating genetic ancestry of commonly used cancer cell lines

Abstract Given the scarcity of human cell lines from under-represented populations available for study, it is crucial that these cell lines be accurately characterized regarding their genetic ancestry so findings can be properly contextualized. Mischaracterization of a cell line's race/ethnicity can lead to wasted time and resources and potentially publication retractions. Here we calculated genetic ancestry proportions for 22 commercially available cell lines to test the accuracy of the “race/ethnicity” categorization assigned to these cells and to provide previously unknown genetic ancestry estimates to the scientific community. To determine cellular genetic ancestry proportions, DNA was extracted from the cell lines and genotyped for ancestry informative markers using the Agena MassARRAY platform with iPLEX chemistry. Genotypes for each cell line were analyzed with STRUCTURE software using settings of 30,000 for burn-in length, 70,000 replications, and K = 3 ancestral populations, representing West African (WA), Native American (NA), and European (EA) input genotype data. Commercially available cell lines designated as “Caucasian” in ethnicity were accurately described with mean European ancestry proportions of 97% (range 92-99%). Recently, using a much smaller panel of markers, the 22Rv1 cell line was found to have 41% WA ancestry. Our genetic ancestry analysis found the 22Rv1 cell line to have mostly EA ancestry, 91% EA, while also containing a non-negligible proportion of WA ancestry (8%). Three of the commercially available cell lines ascribed “Black” race appear to be accurate (HeLa, MDA-MB-PCa2, MDA-MB-468), although two of the three, HeLa and MDA-MBPCa2, fall far below the mean of ~80% WA ancestry for US-born African Americans with 60% and 66% WA ancestry, respectively. Interestingly, the MDA-MB-468 “Black” cell line had an appreciable amount of NA ancestry, 23% NA and 77% WA ancestry, which could suggest possible Afro-Caribbean ethnicity. Most notably, the E006 cell line, designated as “Black,” is as European as the previously mentioned cell lines ascribed Caucasian ethnicity with > 92% EA genetic ancestry. Cell lines with unassigned ethnicity varied widely in genetic ancestry with ranges of WA, NA, and EA ancestry proportions of 1%-92%, 0%-30%, and 2%-96%, respectively. Our results suggest predominantly European ancestry for the Caucasian-designated cell lines and high variance in genetic ancestry proportions for the Black-designated cell lines. However, the E006 cell line is an example of extreme misclassification, which has led to erroneous findings in the disparities literature and leave open the possibility of mischaracterization of other unanalyzed cell lines. Genetic ancestry estimates add more advanced and detailed ancestral characterization to these cell lines and allow for better contextualization of comparisons, applicability, and significant findings. We suggest robust genetic ancestry estimates as a requirement for all current and novel cell lines used in research. Citation Format: Stanley E. Hooker Jr., Madhavi Bathina, Stacy Lloyd, Priyatham Gorjala, Ranjana Mitra, Kevin S. Kimbro, Rick A. Kittles. Estimating genetic ancestry of commonly used cancer cell lines [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr B073.

Response of some wheat genotypes to different salinity levels of Irrigated water

Salinity is one of the major constraints for crop production across the world. Saudi Arabia is dominated with desert environment with high salinity in the central region of the country. Therefore, salinity has a limiting factor for cereal crops in this region. The objective of this study was to assess the productivity and quality characters for some wheat (Triticum aestivum L) genotypes under different salinity levels of Irrigated water (control, 4000, 8000 ppm NaCl). The experiment was conducted during 2011 and 2012 seasons. The trial was conducted under greenhouse environmental condition at Qassim University Agricultural Research and Experimental Station during 2011 and 2012 seasons. Twenty wheat genotypes including: 5 genotypes from ICARDA, 7 genotypes from Pakistan, 5 Australian genotypes, one American genotype (Yocora Rojo), one Egyptian genotype (Sakha 93) and one local genotype (Sama) were used in this study. Results from wheat genotype trial showed a significant difference (p<0.05) for all traits due to increased salinity in irrigation water from 4000 to 8000 ppm. There was a significant difference between the varieties for plant height, 1000-kernel weight, number of kernels spike-1 and Na for grain and straw. The interaction effect was significant in number of spikes, 1000-kernel weight and Na for grain and hay and Na / K cereal. The results showed that Auqab 2000, Bhan 2000 and Shaka 93 have the highest yield at high level of salt and Sis 13, P2 and Local were the least in yield. Moreover, the results of principle component analysis (PCA) indicated that the superior wheat genotypes for grain yield under salt stress in the two seasons (Auqab 2000, Bhan 2000, Yocara Rojo and Sakha 93) are clustered in group D. These genotypes can be considered as salinity resistant varieties. The maximum reduction over control under salt stress was recorded in Australian genotypes (P6 and P9) and local genotype 'Sama'.

Molecular and evolutionary analysis of dengue virus serotype 2 isolates from Korean travelers in 2015

In Korea, dengue infection has been frequently reported in travelers to tropical and subtropical countries. Global warming increases the probability of autochthonous dengue outbreaks in Korea. In this report, the molecular and evolutionary properties of four dengue virus (DENV) type 2 isolates from Korean overseas travelers were examined. Three of these isolates were classified as Cosmopolitan genotypes and further divided into sublineages 1 (43,253, 43,254) and 2 (43,248), while the other isolate (KBPV-VR29) was related to American genotypes. The variable amino acid motifs related to virulence and replication were identified in the structural and non-structural proteins. A negative selection mechanism was clearly verified in all of the DENV proteins. Potential recombination events were identified in the NS5 protein of the XSBN10 strain. The substitution rate (5.32 × 10−4 substitutions per site) and the time of the most recent common ancestor (TMRCA) for each evolutionary group were determined by the Bayesian skyline coalescent method. This study shows that DENV type 2 strains with distinct phylogenetic, evolutionary, and virulence characteristics have been introduced into Korea by overseas travelers and have the potential to trigger autochthonous dengue outbreaks.

Genomic evidence of yellow fever virus in Aedes scapularis, southeastern Brazil, 2016

The southeastern region of Brazil has recently experienced the largest yellow fever disease outbreak in decades. Since July 2016 epizootic events were reported in São Paulo state's north region, where 787 Culicidae were captured as part of public health surveillance efforts and tested using real-time quantitative PCR. One Aedes scapularis pool collected in November 2016 in an agriculture area in Urupês city tested positive for YFV-RNA. Using a validated multiplex PCR approach we were able to recover a complete virus genome sequence from this pool. Phylogenetic analysis of the novel strain and publicly available data indicates that the belongs to the South American genotype 1 clade circulating in Sao Paulo state and is basal to the recent outbreak clade in southeast Brazil. Our findings highlight the need of additional studies, including vector competence studies, to disentangle the role of Aedes scapularis in yellow fever transmission in the Americas.

<p class="Body"><strong>Impact of leaflet trichomes on settlement and oviposition of <em>Tetranychus evansi </em>(Acari: Tetranychidae) in African and South American tomatoes</strong></p>

Red spider mite (Tetranychus evansi) is considered one of the main tomato pests in Africa. As an alternative to chemical control, the use of pest-resistant cultivars has been considered a desirable and environment-friendly choice. Therefore, our study aimed to evaluate the influence of trichomes on settlement and oviposition preferences of T. evansi in African tomato varieties, besides comparing them to South American wild tomato species. First, free- and no-choice laboratory tests were carried out to investigate settlement and oviposition preferences of females on leaflets of two South American wild tomato species (Solanum pennellii LA-716 and S. habrochaites var. hirsutum PI134417) and five African tomato varieties (S. lycopersicum cv. Kekefo, Akikon, TLCV15, Tounvi, and TOML4), the latter are widely grown in Benin. Thereafter, leaf trichome types were determined and densities were estimated and then correlated to numbers of settled females and laid eggs on leaflets of each assessed genotype. According to our findings, females strongly preferred to settle and oviposit on African varieties rather than on South American genotypes. Regarding trichome density, non-glandular type Va showed significant positive correlations with both studied parameters, with the highest amounts in African genotypes. Conversely, glandular trichome density (mainly types I, IV, and VI) presented significant negative correlations with preference indicators, with the largest densities in South American species. The high density of non-glandular trichomes on leaflets of the varieties Akikon, Tounvi, Kekefo, TOML4, and TLCV15 might have been one of the causes of preference of T. evansi females.

PSXI-6 Effects of different feeding strategies during gestation on the reproductive performance of crossbred Landrace-Yorkshire sows

Abstract This study was conducted to investigate the effects of different feeding strategies during gestation on the reproductive performance of sows. A total of 1121 American Landrace-Yorkshire (YL) crossbred sows and parity from 1 to 4 were assigned randomly to “North American System” feeding pattern or “Danish System” feeding pattern during gestation basing on the backfat thickness and body weight. Sows received the same diet and fed ad libitum during lactation. Results showed that over the entire gestation period, there was also no difference in average daily feed intake and total feed intake between two groups (P > 0.05). “Danish System” group has significantly improved the backfat thickness at gestation 30 d (P < 0.01). At 110 d of gestation, there was no difference of the backfat thickness between two groups (P > 0.05). “Danish System” group had significantly increased the total number of born (P = 0.02) and born alive (P = 0.04). The number of total born (P = 0.04), stillborn (P = 0.05) and mummies (P = 0.02), had significantly different in between parities of sows. Mummies had significantly interaction effect (P = 0.01). No different was observed for the number of weaned pigs, litter weight at weaning, piglet weight, and weaning to oestrus interval between two groups. However, a significant increase of litter weight at weaning, piglet weight, was associated with increased parity of sow (P < 0.01). The results of the present investigation showed that “Danish System” group could significantly increase the litter size and number born alive. Our findings point to the importance that the Danish system can be applied to North American genotypes.