Diversity in genetic structure and chemotype composition of <Emphasis Type="Italic">Fusarium graminearum</Emphasis> sensu stricto populations causing wheat head blight in individual fields in Germany

Fusarium head blight (FHB) is one of the most destructive diseases of wheat. Twelve small commercial wheat fields (size 1–3 hectares) were sampled in Germany for Fusarium populations at three spots per field with 10 heads each. PCR assays using generic primers confirmed 338 isolates as F.graminearum sensu stricto (s.s.) (64.9%) out of 521 Fusarium spp. that were further analyzed. Populations of F. graminearum s.s. in Germany contain three types of trichothecenes with a dominancy of 15-acetyldeoxynivalenol chemotype (92%) followed by 3-acetyldeoxynivalenol chemotype (6.8%) and a few isolates of nivalenol chemotype (1.2%). All these isolates were genotyped using 19 microsatellite loci. The 12 populations showed a high genetic diversity within the small scale sampling areas resulting in 300 different haplotypes. Genetic diversity within populations (71.2%) was considerably higher than among populations (28.8%) as shown by analysis of molecular variance. Gene flow (Nm) between populations ranged from 0.76–3.16. Composition of haplotypes of one population followed over 2 years changed considerably. No correlation between genetic and geographical distance was found. In conclusion, populations of F. graminearum s.s. in Germany display a tremendous genetic variation on a local scale with a restricted diversity among populations.     

Biochemical changes and sensory assessment on tissues of carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis>, Linnaeus 1758) during sale conditions

In this study, some biochemical changes of carp (Cyprinus carpio, Linnaeus 1758) tissues were investigated. Studies have been carried out on carp which have regional economical importance. Storage temperature and time are the most important factors that affect the quality of fish during sales. It was observed that the temperature varied between 9 and 12°C in sale conditions. In addition, we assumed the arrival time of the fish at the fish market to be 0 (zero) h. Biochemical analyses [malondialdehyde (MDA) levels and catalase activity] of carp tissues (muscle, liver, heart, spleen, brain) were carried out on fish which were held for 24 and 48 h, as well as on fresh fish (0 h). In addition, sensory analysis was conducted by a panel consisting of experienced judges of sensory evaluation. Statistically significant (P < 0.05) increases in MDA levels were found in liver, muscle, brain and spleen tissues when comparing the 0- and 24-h groups. But there was no statistically significant (P > 0.05) increase in MDA level in heart tissue of carp after 24 h. There was a statistically significant (P < 0.05) increase in MDA levels in muscle, spleen and heart tissues when comparing the 24- and 48-h groups. In the group examined at 24 h, it was observed that there were statistically significant differences from the 0 h group values (P < 0.05) for catalase (CAT) activity in muscle, brain, spleen and heart tissues. The decreases in CAT activity in liver and spleen tissues were found to be statistically significant (P < 0.05) between the group examined at 24 h compared with the group examined at 48 h. Carp maintained good quality during the selling conditions up to 24 h. This experiment deals with the effects of post-slaughter time and storage temperature on carp tissues. It is concluded that by considering the storage temperature (9–12°C) and storage time (post-slaughter) the product maintained acceptable quality up to 24 h. There was significant deterioration of sensory quality, as a result of changes in chemical constituents.     

Breed differences in the pharmacokinetics of ivermectin administered subcutaneously to Holstein and Belgian Blue calves

Belgian Blue (BB) cattle are very sensitive to mange caused by Psoroptes ovis and, in contrast to the case in Holstein cattle, single treatments with ivermectin do not result in complete elimination of the parasite. The objective of the present study was to determine the concentration of ivermectin in plasma, skin and hair following subcutaneous administration to Holstein and BB calves and to assess the influence of breed on drug pharmacokinetics and availability. Two groups of six healthy female Holstein and BB calves were treated with ivermectin (SC formulation) at a dose of 0.2 mg/kg. Blood, skin and hair were collected before treatment and up to 21 days after treatment. Ivermectin was analyzed in plasma and tissue by high-performance liquid chromatography (HPLC). The peak concentrations (Cmax), time-peak concentrations (Tmax), the area under the plasma concentration-time curves (AUC) and the mean residence time (MRT) were determined. The patterns of plasma and tissue ivermectin concentrations were similar in the two breeds of animals, however, the AUC and Cmax levels for plasma and skin were significantly higher in the BB calves. In hair, ivermectin was detected later than in plasma and skin, with the Tmax ranging between 4 days (Holstein group) and 6 days (BB group). The possible reasons for the significantly higher levels in plasma and skin in BB calves compared to Holstein calves are discussed.     

Effects of sodium selenite on some biochemical and hematological parameters of rainbow trout (Oncorhynchus mykiss Walbaum, 1792) exposed to Pb2+ and Cu2+

This study was carried out to understand the preventive effect of selenium (Se⁴⁺) on heavy metal stress induced by lead and copper in rainbow trout (Oncorhynchus mykiss). Variation in glutathione peroxidase (Se-GSH-Px) and superoxide dismutase (SOD) activity, and in malondialdehyde (MDA) levels in liver, spleen, heart, and brain tissues of rainbow trout after 72 h of exposure to Pb²⁺ and Cu²⁺ were investigated in the presence and absence of Se⁴⁺. In the presence of Se⁴⁺, Se-GSH-Px activity and SOD activity were found to be higher and MDA levels were lower compared with in its absence. Hematological parameters were also determined and it has been observed that total leukocyte count (WBC), mean cell volume (MCV), and mean cell hemoglobin (MCH) were increased and erythrocyte number (RBC), hemoglobin (Hb), and hematocrit value (Hct; P < 0.05) were decreased in fish exposed to heavy metals in the absence of selenium. Selenium presence recovered hematological parameters to normal levels. In the light of our findings, it could be stated that Pb²⁺ and Cu²⁺ lead to dramatic changes in biochemical and hematological parameters and selenium caused these parameters to converge to control levels when it was administered concurrently with these heavy metals.     

Pesticide Residue Awareness among Students and Employees in the University of Jordan,Jordan

The objective of the current study was to examine the awareness of employees, students, and community at The University of Jordan about pesticides residue in food and whether they are interested to learn more about it. A questionnaire consisted of 28 questions in three sections was designed and included questions about the demographic characteristics and about the knowledge of the participants about pesticides and their residual limit. Results showed that young respondents with ages between 19–35 years old and with higher educational levels and scientific background were more knowledgeable in many aspects regarding pesticides and their residues, however, this study should be expanded to include higher numbers of respondents, from different universities in Jordan, and among different school backgrounds in order to be able to generalize the results.     

Head-blighting populations of Fusarium culmorum from Germany, Russia, and Syria analyzed by microsatellite markers show a recombining structure

Fusarium culmorum is a haploid, worldwide occurring phytopathogenic fungus causing seedling blight, foot rot, and head blight of cereals and producing the mycotoxins deoxynivalenol (DON) and nivalenol (NIV) associated with health hazards in human and animals. The fungus reproduces asexually by conidiospores, a teleomorph is not known. We analyzed for the first time naturally occurring F. culmorum populations collected randomly in the field from infected wheat heads. A total of 186 isolates, from three populations from Germany (GER), Russia (RUS), Syria (SYR), as well as an international collection (INT) for comparison, were genotyped by 10 microsatellite (SSR, single sequence repeat) markers. A high genetic diversity within the three natural populations and the INT population as well was detected. About 90 % of multi-locus haplotypes (MLH) were unique across populations. The largest part of variance (81 %) was found within populations. Accordingly, population subdivision was low, fixation indices were significant only in one out of six comparisons, while estimates of gene flow (N _m ) ranged from 0.8–4.8. Linkage equilibrium was revealed by the index of multi-locus association and the quotient of observed and expected variance when two linked markers were deleted. DON and NIV chemotypes grouped closely together in a principle coordinate analysis. SYR isolates were partly separated from GER and RUS populations. All population-genetic parameters were in a similar range compared to those for the sexually propagating species F. graminearum. In conclusion, results support the hypothesis of a recombining structure in F. culmorum as revealed by the high genetic variation within populations, a low fixation index and low gametic phase disequilibrium within populations.     

Antioxidative role of selenium against the toxic effect of heavy metals (Cd<Superscript>+2</Superscript>, Cr<Superscript>+3</Superscript>) on liver of rainbow trout (<Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis> Walbaum 1792)

The main purpose of this study is to discuss the effect of Cd⁺², Cr⁺³ and Se metals on biochemical parameters in liver tissue of Oncorhynchus mykiss. The rainbow trout were exposed to heavy metal stress (Cd⁺², Cr⁺³) at 2 ppm dosage. The present study was undertaken to determine the protective effect of selenium treatment at the same dosage (2 ppm) on some biochemical parameters. The activity of catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and the changes in levels of malondialdehyde (MDA) from biochemical parameters were determined in liver tissue of the fish groups exposed to heavy metals, especially for the selenium-applied groups. Results of this study showed that the activities of CAT, GSH-Px and SOD in the tissues of fish exposed to the stress of Cd⁺² and Cr⁺³ were significantly lower than the control groups (P < 0.05). Meanwhile, the closer values to the control groups were obtained in selenium-added groups (Cr⁺³ + Se⁺⁴, Cd⁺² + Se⁺⁴). For the level of MDA, the last production of lipid peroxidation showed increases (P < 0.05) in the groups exposed to the metal stress, whereas significant decreases were obtained in selenium-applied groups. The result of the statistical evaluation showed that the negative effects occurring in the biochemical parameters of the applied groups exposed to the toxicity of heavy metal were significantly eliminated (P < 0.05) as a result of selenium treatment.     

Within-field variation of Fusarium graminearum isolates for aggressiveness and deoxynivalenol production in wheat head blight

Fusarium head blight (FHB), caused by Fusarium graminearum sensu stricto (s.s.), causes tremendous annual yield losses in wheat worldwide. Variation of aggressiveness of isolates from individual field populations in terms of FHB infection and deoxynivalenol (DON) concentration in the host are important population parameters reflecting parasitic ability. Our main objective was to estimate the variation of both traits within three populations of F. graminearum s.s., each consisting of 30 single-spore isolates collected from small wheat fields in Germany, and to compare it with 11 isolates of a collection (F. graminearum collection) from four countries. The same isolates were characterized using 19 single-sequence repeat markers. All isolates were spray inoculated on a moderately resistant spring wheat cultivar at two field locations over 2 years (i.e., in four environments). The genotypic proportion of phenotypic variance (σ(2)(G)) within populations was significant (P < 0.01) for both traits, and the σ(2)(G) × environment interaction was even more important for mean FHB severity. Ranges in mean FHB severity and DON concentration in the host were only slightly smaller for the field populations than for the F. graminearum collection. Both traits were significantly (P < 0.05) correlated within and across populations. A further partitioning of σ(2)(G) revealed 72% of σ(2)(G) within and 28% of σ(2)(G) across populations for both traits. Molecular variance of the three populations was similarly distributed (73.6% within versus 26.4% between populations). In view of this high within-field variation for traits of parasitic ability and selection, neutral molecular markers, multiple resistance genes of different origin should be employed in wheat breeding programs to obtain a long-term stable FHB resistance.