Authors:H. Mahmoudi, M. Salari, M. Ghayeb Zamharir and M. Ghorbani
A safflower disease was observed in the fields of South Khorasan (Iran) in 2017–2018. Affected plants had extensive fasciation, bushy growth, small leaves, phyllody and shortened internodes. Polymerase chain reaction (PCR) assays were performed using universal phytoplasma primers pairs P1/P7, R16mF1/mR1 and M1/M2 to detect putative phytoplasma (s). Nested PCR analyses showed that all symptomatic plants were positive for phytoplasma infection, while asymptomatic plants were negative. Nucleotide sequence analysis and RFLP analyses of PCR-amplified 16S rDNA sequences indicated that safflower fasciation in Iran was associated with a phytoplasma that belonged to the peanut witches' broom group (16SrII). Phylogenetic analysis confirmed that safflowers fasciation phytoplasma (SaP) must be classified in ‘Candidatus phytoplasma aurantifolia’ (16SrII) taxonomic group. To our knowledge, this is the first documentation of a phytoplasma associated with safflower fasciation in Iran and the world.
Authors:A. Bachir, I. Selmi, A. Lehad, M. Louanchi and N. Mahfoudhi
Rugose wood disease constitutes one of the major grapevine disease complexes causing significant economic damage worldwide. It is widely distributed in all grapevine growing areas of the world and comprised of four individual syndromes, which may be caused by different viruses. These syndromes are Corky bark, LN 33 stem grooving, Kober stem grooving and Rupestris stem pitting (RSP). The present study focuses on the prevalence of three viruses associated with rugose wood complex (RWC) in Algeria.
Field inspections and collection of symptomatic samples were conducted on autumn 2012 in the table wine and autochthone accession in the western and central regions of Algeria. A total of 202 samples were tested by RT-PCR using specific primers for Grapevine virus A (GVA), Grapevine virus D (GVD) and Grapevine rupestris stem pitting associated virus (GRSPaV).
The results of RT-PCR indicated the presence of the viruses GVA, GVD and GRSPaV with 68,81% (139 out of 202 infected samples) total average infection rate. The results also indicated the predominance of GRSPaV compared to the prevalence of GVA and GVD with an infection rate of 57,92% vs. 36,63% (74 out of 202) and 2,97% (6 out of 202), respectively. Mixed infections of these three viruses were not observed in any of the samples analysed, however the mixed infection of GVA and GRSPaV was noted with a high rate of 26.73%. The grapevine cultivars; Kings Rubi, Carignan and Mersguerra were the most infected, while the Alicante Bouschet cultivar presented the lowest infection rate. To the best of our knowledge, the present study reports for the first time on the presence of GVD in Algeria.
Authors:Hagen Frickmann, Andreas Hahn, Stefan Berlec, Johannes Ulrich, Moritz Jansson, Norbert Georg Schwarz, Philipp Warnke and Andreas Podbielski
Introduction: Escherichia coli and Staphylococcus aureus are important causes of severe diseases like blood stream infections. This study comparatively assessed potential differences in their impact on disease severity in local and systemic infections.
Methods: Over a 5-year interval, patients in whom either E. coli or S. aureus was detected in superficial or primary sterile compartments were assessed for the primary endpoint death during hospital stay and the secondary endpoints duration of hospital stay and infectious disease as the main diagnosis.
Results: Significance was achieved for the impacts as follows: Superficial infection with S. aureus was associated with an odds ratio of 0.27 regarding the risk of death and of 1.42 regarding infectious disease as main diagnosis. Superficial infection with E. coli was associated with a reduced duration of hospital stay by −2.46 days and a reduced odds ratio of infectious diseases as main diagnosis of 0.04. The hospital stay of patients with E. coli was increased due to third-generation cephalosporin and ciprofloxacin resistance, and in the case of patients with S. aureus due to tetracycline and fusidic acid resistance.
Conclusions: Reduced disease severity of superficial infections due to both E. coli and S. aureus and resistance-driven prolonged stays in hospital were confirmed, while other outcome parameters were comparable.
Authors:E. Feoli, P. Ganis, J. J. Ibáñez and R. Pérez-Gómez
In this paper, we want to support the idea of using a family of indices of similarity, that we call the Simpson's family indices or nestedness-based similarity functions (NBSF) for comparing operational geographic units (OGUs) (phytosociological relevés, animal traps, watersheds, administrative units, industrial areas, islands etc.). In these cases, similarity-dissimilarity depends, in addition to factors that induce replacement, also on factors that produce reduction or increment in the number of features within the same typology of OGUs (e.g., extent, reduction of fertility, anthropogenic pressure etc.). To keep into consideration this aspect, the indices are defined to be equal to 1 when the OGUs are completely nested. The results of the application to four simulated data sets prove that, when the data set does not show clear nested pattern, the use of NBSF produces results similar to the nestedness-free similarity functions, however since NBSF clearly detect nested situations, we should prefer their use in the circumstances where we think important to put in evidence nestedness. In conclusion, we support the idea of using both types of indices in order to improve the knowledge about the structure of any data set.
Authors:S.B. Lade, N. Nicholson-Sabaté and V. Medina
The effect of Azospirillum brasilense Sp7 (Sp7) on maize (Zea mays, Mill cv. B73) seedlings was compared when using two common carriers to deliver Sp7 to the seed: phosphate buffered saline (PBS) and magnesium sulfate (MgSO4). Seedling height, leaf chlorophyll levels, and root growth parameters were analyzed with WinRHIZO® at an early vegetative stage of plant development. Scanning and transmission electron microscope (SEM & TEM) analysis showed that carrier components do not effect bacterial binding to plant roots. MgSO4 + Sp7 caused a significant increase in the abundance of thick lateral roots, but stunted plant height, compared to other treatment groups, while relative chlorophyll contents (SPAD) significantly increased in seedlings inoculated with PBS + Sp7, revealing that the two inoculation carriers differentially affect the Sp7-associated plants.
Authors:Muhammad Saad, Helen Mary, Umar Amjid, Ghulam Shabir, Kashif Aslam, Shahid Masood Shah and Abdul Rehman Khan
Tartary buckwheat, known for its rich source of health beneficial secondary metabolites, is cultivated in many areas of the world. Among different environmental factors, photoperiod strongly influence its growth, flowering time, and ultimately the yield. In this context, epigenetics could contribute significantly in the regulation of plant response against changing environment. Therefore, with the aim to study the involvement of DNA methylation in photoperiod mediated plant response, genome-wide DNA methylation analysis was performed in two accessions (A1 and A2) of Tartary buckwheat using three photoperiodic treatments, i.e., 10-hr light/day (T1), 12-hr light/day (T2), and 14-hr light/day (T3). Flowering time and plant fresh weight data revealed that accessions A1 and A2 prefer T1 and T2 treatments, respectively. Total DNA methylation ratio increased with the increase in photoperiod in accession A1 but decreased under same conditions in accession A2. Full methylation increased significantly while intensive decrease in hemimethylation was noted from T2 to T3 in A1, whereas full methylation strongly increased and hemimethylation strongly decreased from T1 to T2 in A2. Overall, the DNA methylation events appeared more frequently than demethylation events. This study reports for the first time an accession-/genotype specific pattern of shift in the DNA methylation under different photoperiodic treatments that will pave the way toward identification of specific genes involved in the regulation of plant response against photoperiodic stress.
Treatment of barley grain with gibberellic acid (GA3) during malting promotes abnormal proteolysis and rapid rootlets growth affecting malt quality. This study investigated the potential of ethylene treatment as an alternative by comparing the amylase activity, total starch and total reducing sugars of germinating ‘Puma’ barley seeds treated with ethylene, 1-methylcyclopropane (1-MCP), GA3, daminozide (B-nine), GA3 + 1-MCP, ethylene + B-nine and the control after 24, 48 and 72 h from soaking. Ethylene had no effect on amylase activity. B-nine reduced amylase activity by 16 and 9.6% compared to the control after 48 and 72 h, respectively. The amylase activity of ethylene + B-nine treated seeds was higher (13.3 and 4%) than B-nine treated seeds after 48 and 72 h. This suggest that endogenous GA is important for normal amylase activity and, ethylene stimulates amylase activity where GA synthesis is inhibited. Ethylene and GA3 treatments reduced starch (83.3 mg g−1 and 76.7 mg g−1, respectively) and increased reducing sugars (16.0 and 17.1 µg ml−1, respectively) compared to the control (115.3 mg g−1 starch and 12.1 µg ml−1 reducing sugars) after 72 h. It was concluded that, ethylene may replace GA3 treatment without interfering with starch changing processes during barley malting.
Authors:S. Kribel, S. Qostal, A. Ouazzani Touhami, K. Selmaoui, A. Mouria, R. Benkirane, El. H. Achbani and A. Douira
Thirty Trichoderma isolates isolated from compost, various crops and soil with roots of adjacent sites to the phosphate mines of Morocco, were tested in vitro for their potential to solubilize phosphorus from phosphate rock. The qualitative assessment of phosphate solubilization by Trichoderma isolates was performed on Modified Pikovskaya Agar (MPA) solid medium. The visual observation of the 3- and 6-day-old cultures did not show any clear zone around the colony. However, all the isolates were able to grow on the culture medium 3 days after incubation, the maximum recorded diameter was 58.6 mm for isolate TR-B 98 (3) and the minimum value was 34.8 mm for isolate TS-EM-98 (2). After 6 days, they showed good radial growth that exceeded 79.8 mm with variable appearance of the mycelial density such as the isolates TS-B 98, TS-EM-98 (1) and TR-CB 2000 (1) that presented, respectively, high, regular and low mycelial density. Also, the Trichoderma isolates produced variable number of conidia on MPA medium. Quantitative estimation on the Modified Pikovskaya Broth (MPB) liquid medium showed a variable potential of the Trichoderma isolates to solubilize phosphate when the amount of soluble phosphorus remained low in the liquid medium without the fungus (0.26 mgL−1). The maximum concentration of soluble phosphorus was 11.92 mgL−1 with percentage of soluble phosphorus equal to 95.39% recorded by the isolate TR-TB 2000 after 9 days of incubation, followed by the isolates TR-B 98 (3), TS-B 98 and TR-EM 2 respectively, 11.20, 10.47 and 9.61 mgL−1 and 89.6, 83.76 and 76.38%. In addition, treatments with Trichoderma isolates provided a lower final broth pH which varied between 6.81 for TOL isolate and 3.40 for TS-B-2000 (2) compared to initial pH (7.2). The isolates that proved potent for phosphate solubilization displayed the highest fresh and dry weights such as TR-TB 2000 (FW = 4.11 g and DW = 2.56 g), while the lowest fresh and dry weight were noted in the weakest isolates for phosphate solubilization such as T27 (FW = 1.025 g and DW = 0.58 g).
The high solubilization potential of Trichoderma isolates can be exploited for the solubilization of fixed phosphorus present in the soil, thus improving soil fertility and plant growth.
Authors:Esra Aciman Demirel, Mumin Alper Erdoğan, Bilge Piri Cinar and Oytun Erbas
Agomelatine is a potent MT1 and MT2 melatonin receptor agonist and a 5-HT2C serotonin receptor antagonist. The purpose of this study was to show the convulsion-reducing effect of agomelatine, in both clinical and electrophysiological terms, in a pentylenetetrazole (PTZ)-induced experimental epilepsy model in rats.
The anticonvulsant activity of agomelatine (25 and 50 mg/kg) was evaluated in rat models of PTZ (35 and 70 mg/kg) and compared with the control groups.
Agomelatine administration at doses of 25 and 50 mg/kg resulted in a statistically significant decrease in convulsion scores and time to onset of myoclonic jerks compared to the control groups. In addition, comparison of the two doses employed showed that high-dose agomelatine (50 mg/kg) was significantly more effective than the lower dose. In addition to previous studies, we investigated the anticonvulsant effect of agomelatine using electroencephalogram (EEG). Administration of agomelatine at doses of 25 and 50 mg/kg in PTZ-induced seizures caused a significant decrease in the percentage of peak at EEG.
Our results suggest that agomelatine has anticonvulsant activity shown in PTZ-induced seizure model. The results also give some evidences that agomelatine can use on epileptic seizures, but more studies are needed.
Authors:M. I. E. Arabi, E. Al-Shehadah and M. Jawhar
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.