Browse

You are looking at 81 - 90 of 5,595 items for :

  • Biology and Life Sciences x
Clear All

Cochliobolus sativus, the causal agent of common root rot (CRR), is a devastating fungal pathogen of barley that can cause significant yield losses worldwide. The development of resistant cultivars has proven difficult, therefore, in this work, CRR-resistant barley germplasm was developed by crossing three resistant-by-susceptible cultivars currently used in Europe and West Asia. Following greenhouse evaluations of 150 doubled haploid lines derived from these crosses, 40 lines were evaluated under artificial infection conditions using incidence and severity parameters during two consecutive seasons. Data showed significant differences among barley lines with a continuum of resistance levels ranging from highly susceptible to resistant which were consistent in both seasons. However, five promising lines had slightly lower CRR disease than the others. Additionally, significant differences (P <0.05) in mean incidence and severity values were found among lines, with values being consistently higher in the susceptible ones. However, CRR severity increased linearly as incidence increased in both seasons. All together, the present study suggests that, the newly identified resistance lines can serve as potential donors for ongoing CRR resistance breeding program to generate high-yielding commercial barley cultivars, and that the positive correlation between CRR parameters I and S may be beneficial for many types of studies on this disease.

Restricted access
Authors: Gaigai Du, Liyuan Wang, Huawei Li, Peng Sun, Jianmin Fu, Yujing Suo, Weijuan Han, Songfeng Diao, Yini Mai and Fangdong Li

Background and aims

Persimmon (Diospyros kaki) is an economically important fruit tree species with complex flowering characteristics. To obtain accurate expression pattern analysis results, it is vital to select a reliable gene for the normalization of real-time quantitative polymerase chain reaction data. The aim of this study was to identify the optimal internal control gene among six candidate genes for gene expression analysis in different persimmon organs and developmental stages.

Materials and methods

This analysis was conducted using geNorm and NormFinder software to show differences in the stability of the six reference genes among tissues and floral developmental stages of the same plant.

Results

Although genes that exhibited moderate expression in NormFinder revealed slightly different expression stabilities than those obtained by geNorm, both sets of results showed that GAPDH was the best reference gene in different organs and floral buds at different developmental stages, whereas 18SrRNA was the least stable gene.

Conclusions

Based on the overall ranking, GAPDH is the most suitable reference gene and is highly recommended for gene expression studies in different organs and different developmental stages of persimmon. This study provides useful reference data for future gene expression studies and will contribute to improving the accuracy of gene expression results in persimmon.

Restricted access

Introduction

Hepatocellular carcinoma (HCC) is found within the first five most common tumors worldwide. Sorafenib is an approved agent in HCC treatment. Sertraline is a selective serotonin reuptake inhibitor. The aim of the study is to investigate the combination of sertraline and sorafenib at hepatocellular cancer cell proliferation and death.

Methods

HepG2 cells were treated with drugs and viability test XTT was performed. Cells were stained with hematoxylin and eosin for histological examination or with anti-Bcl-2 antibody and Hoechst 33258 for immunofluorescence.

Results

Viability results supported dose-dependent antiproliferative effect for both sertraline and sorafenib. Microscopic evaluation of stained cells exerts morphological changes.

Discussion

This is the first study to show that sorafenib and sertraline have synergistic effect in hepatocellular cancer.

Restricted access

Introduction: The study was performed to estimate the prevalence and determinants of occurrence of sexually transmitted infections (STIs) in paratroopers and navy soldiers by anonymously analyzing medical records from the medical departments of two large German barracks in order to assess the need for medical STI prevention.

Methods: Medical records from 80 paratroopers and 80 navy soldiers were screened for records of STI. Results were anonymously collected next to information on risk factors, as well as diagnostic and therapeutic management, and comparatively assessed.

Results: Proportions of suspected STIs were 17.5% and 20%, and proportions of diagnosed STIs were 13.9% and 11.3% for paratroopers and navy soldiers, respectively. Chlamydia trachomatis, human papillomavirus, and genital scabies were observed in paratroopers and navy soldiers, while Gardnerella vaginalis, herpes simplex virus, Molluscum contagiosum virus, Neisseria gonorrhoeae, and Trichomonas vaginalis were additionally identified in navy soldiers.

Conclusions: Although clinical hints for STIs were frequently observed, clinical management was usually restricted to syndrome-based antibiotic treatment without detailed diagnostic workup, leaving room for procedural improvement. Ongoing need for medical STI prevention in the military could be confirmed.

Open access

Bacillus thuringiensis (B.t) is well known for its biocontrol potential against a variety of insects. Nematicidal potential of ten B.t isolates was tested against root-knot nematodes (Meloidogyne javanica (Treub) Chitwood) in vitro, under greenhouse as well as in field conditions. Eggs and second stage juveniles (J2) were exposed to 5 and 25% concentrations of bacterial cell-free aqueous extracts up to 96 h. B.t isolates showed lesser degrees of nematicidal activity at 5% concentration. However, some B.t isolates (B.t-14, B.t-16 and B.t-64) greatly reduced egg hatching and increased J2. All B.t isolates revealed suppressed egg hatching and increased mortality of J2 at 25% concentration. Soil applications with most of the B.t isolates under greenhouse and field conditions significantly improved height and fresh weights of root-knot nematode parasitized okra (Abelmoschus esculentus (L.) Moench). Some isolates, including B.t-64 reduced the number of galls and egg masses. B.t-64 reduced gall formation up to 70% under greenhouse conditions. However, 29% of decrease was observed in field conditions. Similarly, B.t-64 treated plants showed a 56% decreased in eggs/egg mass in a field experiment. Population of root-knot nematodes in the rhizosphere was decreased up to 61% in the field experiment as compared to control.

Restricted access
Authors: A. Bellatreche, S.R. Mnasri, M. Ben Naceur and S.S.B. Gaouar

Climate change has significantly affected wheat yield. Many studies have suggested that rising temperatures could be harmful to cereals around the world. Thus, the valorization of the desert wheat resources is essential to improve the resistance of this species to climate change. In this context, twenty-eight different local Saharan bread wheat (Triticumaestivum L.) genotypes were described using ten preselected SSR markers. The tested SSRs produced a total number of 20 alleles with an allelic size ranged from 100 pb (WMC261) to 400 pb (WMC257). The allele frequency varied from 0.1 for the allele 230 pb (WMC156) to 1 for the alleles 187 pb, 310 pb (WMC97, WMC168). Likewise, the PIC values ranged from 0 (WMC97, WMC168) to 0.5 (WMC327, WMC233), with an average of 0.34 and the observed heterozygosity (Ho) from 0 to 0.88, with an average of 0.55. The molecular variance (AMOVA) revealed the highest level of intra-population differentiation of local Saharan bread wheat (97%) and the statistical geometric distributions based on PCoA, NJ method and structure analysis confirmed the existence of four major classes of bread wheat. These results substantiate the previous researches based on the morphological markers and contribute for the first time in Algeria to create the genetic fingerprint of the Saharan bread wheat resources and to valorize their drought resistance potential through breeding programs.

Restricted access
Authors: C. Calderón del Cid, R. S. Rezende, A. R. Calor, J. S. Dahora, L. N. de Aragão, M. L. Guedes, A. N. Caiafa and A. O. Medeiros

Abstract

Leaf litter breakdown is an important process in riparian ecosystems, regulated by the concomitant fluctuations of allochthonous organic matter input (quality and quantity), the environmental conditions, and the decomposer community. Our objective was to assess the effects of temporal variability of litter quantity and quality over the stream's decomposer community. We hypothesized that the litter effects over the decomposer community would be overruled by Cerrado's harsh environmental conditions. Precipitation fluctuations, especially during dry and rain seasons, did modify the litterfall periodicity, but not the average organic matter entering the system or the litterfall triggers. Fifteen riparian species were identified contributing with organic matter into the stream, however, Richeria grandis contributed with 48% of litter biomass, helping explain the nutritional intra-annual balance given by the litter chemistry, that would be determinant for ecosystem stability. Higher aquatic hyphomycetes sporulation rates and invertebrate density during the dry season suggest that the decomposer community required a more stable environment (consistent low current) in order to colonize and exploit leaf litter. Our results point out that physical fragmentation was the predominant driver of litter breakdown for our system, due to high decomposition rates, litter remaining mass correlated negatively with precipitation, and low decomposer abundance and activity. Invertebrate collectors' abundance was negatively correlated with litter remaining mass and showed no temporal variation, suggesting that this functional group may have benefited from the particulate organic matter produced by physical fragmentation. Therefore, annual temporal variations on Brazilian savanna stream systems may drive the functioning of the ecosystem.

Restricted access
Authors: S. Feranchuk, N. Belkova, U. Potapova, I. Ochirov, D. Kuzmin and S. Belikov

Abstract

The methods for data presentation are important in bioinformatics as data processing algorithms. The article describes the software package for the extensive analysis of tables with estimates of bacterial abundance levels in environmental samples. The package was designed to be executed in a distributed hardware environment, with powerful packages in Python in the backend and interactive front-end forms. Most of microbial ecology-specific functionality is implemented by the scikit-bio Python package, together with the other Python packages intended for big data analysis. Interactive visualisation tools are implemented by the D3.js software library, therefore, the software project is named D3b. The package is a suite of tools for the analysis of microbial ecology data implemented as a web-service and as a desktop application. It supports a substantial part of the graphical and analytical descriptions of microbial communities used in scientific publications. Source codes are available at github (sferanchuk/d3b_charts) and the on-line version of the system is accessible at d3b-charts.bri-shur.com.

Restricted access

Avena spp. were artificially inoculated with Fusarium culmorum Sacc. (FC) and F. graminearum Schwabe (FG) causing Fusarium head blight (FHB). This disease is often accompanied by the accumulation of Fusarium mycotoxins mainly deoxynivalenol (DON) in grains. The contaminated grains with this mycotoxin are toxic to their consumers. Genotypes Avena spp. with low DON accumulation in grains can be used as genetic resources suitable for the formation of new resistant varieties of oats against FHB caused by fungi FC and FG. The aim was to find out and to compare the potential for mycotoxin accumulation in grains between genotypes of Avena spp. after artificial inoculation panicles by FC and FG using three spray methods and identify genotypes of Avena (A. abyssinica, A. byzantina, A. canariensis, A. fatua, A. ludoviciana, A. nuda, A. sativa, A. sterilis, A. strigosa) with low toxin accumulation in whole grain. The average accumulations of DON in the grains of Avena spp. gradually increased from the spray inoculation (0.68 mg · kg−1), spray + polyethylene (PE) bag cover 24 hrs (2.75 mg · kg−1) and spray + PE bag/48 hrs. (9.46 mg · kg−1) methods. We found out that after application of each used method, the high DON accumulation in grains was found in A. canariensis, and low DON levels were found in A. byzantine and A. sterilis.

Restricted access

Abstract

We briefly complement Endrédi et al. (2019) forum paper from terrestrial animal ecological points of view. We discuss the origins of trait-based approach, challenges of trait classifications, and we provide an example of a commonly used trait, body size.

Open access