Since the introduction of West Nile virus (WNV) to North America in 1999, WNV is estimated to have contributed to population-level declines in numerous avian species. However, the potential impacts ...of this virus on many free-ranging upland game bird species, including the wild turkey (Meleagris gallopavo), which is undergoing regional population declines, remain unknown. Herein, two age groups (∼5 to 6 weeks and ∼15 to 16 weeks post-hatch) of juvenile wild turkeys were subcutaneously inoculated with WNV, sampled daily from 1 to 7 days post-inoculation (dpi), and euthanized on 14 dpi. No clinical signs and minimal gross lesions were attributable to WNV infection. Peak viraemia titres were similar between age groups (<10
1.7
to 10
4.6
plaque-forming units PFU/ml), but the duration of viraemia was longer in the old group (3-4 days) than in the young group (0-3 days). Intermittent oral and/or cloacal viral shedding from 2 to 7 dpi was detected in both age groups. No infectious virus was detected in the heart, brain, kidney, skeletal muscle, spleen, and feathers from WNV-inoculated turkeys euthanized on 14 dpi. All WNV-inoculated birds seroconverted by 14 dpi, as well as two co-housed sham-inoculated birds. The most consistent microscopic lesions among all WNV-inoculated birds were mild lymphoplasmacytic myocarditis and encephalitis. Minimal immunohistochemical labelling was detected in tissues in addition to scant macrophages within the blood, spleen, and bone marrow. These data suggest WNV is unlikely to pose a significant risk to wild turkey populations, although the possibility remains that WNV may indirectly decrease fitness or predispose wild turkeys to other health stressors.
RESEARCH HIGHLIGHTS
Clinical disease was not observed in wild turkeys experimentally infected with WNV.
Pathology attributed to WNV was mild and included brain and heart inflammation.
Viraemias suggest WNV-infected wild turkeys do not play a role in WNV transmission.
No age-associated differences in WNV clinical disease or pathology were observed.
The study aim was to determine the best inoculation route for virulotyping Enterococcus cecorum in a chicken embryo lethality assay (ELA). Twenty-eight genetically different strains were used. ...Fourteen strains were isolated from cloaca swabs of broiler reproduction chickens (cloaca strains) and 14 strains from broilers with E. cecorum lesions (lesion strains). In all ELAs, 12-day incubated embryonated broiler eggs were inoculated with approximately 100 colony-forming units of E. cecorum/egg. Twenty embryos per inoculation route and strain were used in each of three experiments. In Experiment 1, four cloaca and four lesion strains were inoculated via various routes, i.e. albumen, amniotic cavity, allantoic cavity, chorioallantoic membrane, intravenous or air chamber. The albumen inoculation route showed low mortality with cloaca strains, high mortality with lesion strains and the largest difference in mortality between these groups of strains (≥60%). This route was therefore used in subsequent experiments. In Experiment 2, the same strains were used to test reproducibility, which proved to be generally good. All 28 strains were thereafter used in Experiment 3. In the three experiments, mortality caused by cloaca and lesion strains ranged from 0-25% and from 15-100%, respectively. Recovery rates, assessed in all experiments after albumen inoculation, were significantly lower from eggs inoculated with cloaca strains, compared to lesion strain-inoculated eggs (P < 0.05). However, the bacterial load of eggs with positive recovery was similar in both groups. In conclusion, the albumen inoculation route appeared to be the best to virulotype E. cecorum strains.
RESEARCH HIGHLIGHTS
The albumen route is the best to differentiate between E. cecorum strains.
Egg albumen likely affects cloaca E. cecorum strains more than lesion strains.
Based on SNPs, E. cecorum cloaca strains are clustered as well as lesions strains.
•Fermentation through single inoculation and co-inoculation of lactic acid bacteria.•Fermentation decreases volatile compounds (VOCs) with undesirable flavors.•Fermentation increases VOCs with ...excellent flavors.•Fermentation produces new VOCs with characteristic flavors.•Transformations mainly involved oxidation, reduction, hydrolysis, and isomerization.
The influence on and biotransformation of volatile compounds (VOCs) during fermentation of Elaeagnus moorcroftii Wall.ex Schlecht. juice (EWSJ) through single inoculation and co-inoculation of Bifidobacterium animalis subsp. lactis HN-3 (B.an3) and Lacticaseibacillus paracasei YL-29 (L.cp29) were analyzed through headspace-solid phase microextraction-gas chromatography-mass spectrometry. Compared with the B.an3- and L.cp29-fermented EWSJ, the B.an3 + L.cp29-fermented EWSJ had more increased 9 desirable flavor compositions and less decreased in or even elimination of 12 undesirable flavor compositions, and 3 new characteristic VOCs, formed through the interaction between B.an3 and L.cp29 were detected. In addition, biotransformations that led to an increase and a decrease in VOCs mainly involved 3 oxidation, 3 reduction, 1 hydrolysis, and 1 isomerization reactions. This study offers a theoretical basis for investigating the interaction effect of Lactobacillus and Bifidobacterium species on VOCs and developing lactic acid bacteria-fermented plant-based juices with lower sugar content and better flavor.
Coconut is a crop of economic importance, and protocols for the propagation
in vitro
of coconut are already in use. However, during acclimatization, some micropropagated plants or plantlets do not ...survive. There are reports that show that the application of arbuscular mycorrhizal fungi (AMF) improves the development of plants. So far, there are no reports of acclimatization of coconut plantlets with or without AMF. Therefore, this study reports the evaluation of survival and growth during acclimatization of coconut plantlets (obtained by somatic embryogenesis) testing inoculation with native or commercial AMF. Survival increased from 1.19 to 1.24-fold with native AMF, but no increase occurred with commercial AMF. Growth and photosynthetic parameters were evaluated, and there were no significant changes among treatments at 180 d. However, 6 mo later, there was a significant increase in height, leaf area, and stem diameter in plantlets inoculated with commercial AMF. There were differences in the development of secondary roots when plantlets were treated with commercial AMF. The colonization with native AMF showed a greater proportion of coils and hyphae, whereas, with commercial AMF, arbuscules and hyphae were more abundant. According to this study’s results, AMF inoculation can be recommended to improve the survival and growth of micropropagated coconut plantlets.
Fusarium graminearum Lofgren, Lotus A.; LeBlanc, Nicholas R.; Certano, Amanda K. ...
The New phytologist,
February 2018, Letnik:
217, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Mycotoxin-producing Fusarium graminearum and related species cause Fusarium head blight on cultivated grasses, such as wheat and barley. However, these Fusarium species may have had a longer ...evolutionary history with North American grasses than with cultivated crops and may interact with the ancestral hosts in ways which are biochemically distinct.
We assayed 25 species of asymptomatic native grasses for the presence of Fusarium species and confirmed infected grasses as hosts using re-inoculation tests. We examined seed from native grasses for the presence of mycotoxin-producing Fusarium species and evaluated the ability of these fungi to produce mycotoxins in both native grass and wheat hosts using biochemical analysis.
Mycotoxin-producing Fusarium species were shown to be prevalent in phylogenetically diverse native grasses, colonizing multiple tissue types, including seeds, leaves and inflorescence structures. Artificially inoculated grasses accumulated trichothecenes to a much lesser extent than wheat, and naturally infected grasses showed little to no accumulation.
Native North American grasses are commonly inhabited by Fusarium species, but appear to accommodate these toxigenic fungi differently from cultivated crops. This finding highlights how host identity and evolutionary history may influence the outcome of plant–fungal interactions and may inform future efforts in crop improvement.
Claviceps purpurea
causing ergot maintains to be a problem in commercial cytoplasmic male sterile (CMS)-based hybrid rye growing. The fungal spores compete with pollen during flowering and ergot ...incidence is reduced in highly pollen-shedding stands. This study was carried out to identify maternal differences in ergot infection in the absence of pollen. Ten male-sterile single crosses were tested by needle and spray inoculation and kept unfertilized in up to four field sites (Germany, Austria) and three greenhouse experiments, respectively, in two years. A medium to high correlation was observed between field (needle inoculation) and greenhouse (spray inoculation) experiments. The environments (=location × year combinations) differed in their ergot severity and ergot incidence. Significant (
P
≤ 0.05) genotypic and genotype × environment interaction variances were detected for the unfertilized male-sterile single crosses in both test systems for both traits. The single cross K_4 showed a significantly lower ergot severity averaged across all environments, thus being more resilient to ergot than the other genotypes. In conclusion, spray and needle inoculation are suitable for testing unfertilized male-sterile rye materials, testing across several environments (locations, years) is definitely necessary. Selection of specific females might give the potential for further reducing ergot contamination in hybrid rye in future. The frequency of such genotypes within larger breeding populations needs to be analyzed.
Les levures qui font partie des microorganismes, du compost utilisé dans la fertilisation du sol, ont attiré notre attention. Leur isolement, leur dénombrement et l'étude de leurs caractères ...culturaux et morphologiques ont révélé leur diversité et leur nombre élevé au niveau de ce produit. Les isolats sélectionnés CHI4, CPI3 et CEI2 ont montré une tolérance très importante aux trois types de stress étudiés en particulier la levure CEI2 qui résiste à un pH très acide (2,5), à une température élevée (42 °C) et à une concentration en NaCl de 600 mM. Les cultures du haricot sur différents supports contenant ou non des levures issues de compost nous a permis de mettre en évidence leur effet positif sur le poids sec de la plante étudiée (Phaseolus vulgaris) par une augmentation de 700 %, 500 % et 400 %, par rapport au sol, avec CEI2, CPI3 et CHI4 respectivement. Cette augmentation dépasse de 1,5 fois le compost de l'été à partir duquel on a isolé la levure CEI2, de 1,4 fois le compost du printemps à partir duquel on a isolé la levure CPI3 et de 2,7 fois le compost de l'hiver à partir duquel on a isolé la levure CHI4. Ces trois levures et en particulier la CEI2 sont donc intéressantes pour une éventuelle utilisation dans la Biofertilisation des sols et l'augmentation du rendement de cette légumineuse. Mais si le sol est très acide avec une température très élevée dépassant les 40°C, la levure CEI2 sera une bonne candidate par rapport aux deux autres.
Les levures qui font partie des microorganismes, du compost utilisé dans la fertilisation du sol, ont attiré notre attention. Leur isolement, leur dénombrement et l'étude de leurs caractères ...culturaux et morphologiques ont révélé leur diversité et leur nombre élevé au niveau de ce produit. Les isolats sélectionnés CHI4, CPI3 et CEI2 ont montré une tolérance très importante aux trois types de stress étudiés en particulier la levure CEI2 qui résiste à un pH très acide (2,5), à une température élevée (42 °C) et à une concentration en NaCl de 600 mM. Les cultures du haricot sur différents supports contenant ou non des levures issues de compost nous a permis de mettre en évidence leur effet positif sur le poids sec de la plante étudiée (Phaseolus vulgaris) par une augmentation de 700 %, 500 % et 400 %, par rapport au sol, avec CEI2, CPI3 et CHI4 respectivement. Cette augmentation dépasse de 1,5 fois le compost de l'été à partir duquel on a isolé la levure CEI2, de 1,4 fois le compost du printemps à partir duquel on a isolé la levure CPI3 et de 2,7 fois le compost de l'hiver à partir duquel on a isolé la levure CHI4. Ces trois levures et en particulier la CEI2 sont donc intéressantes pour une éventuelle utilisation dans la Biofertilisation des sols et l'augmentation du rendement de cette légumineuse. Mais si le sol est très acide avec une température très élevée dépassant les 40°C, la levure CEI2 sera une bonne candidate par rapport aux deux autres.
Les levures qui font partie des microorganismes, du compost utilisé dans la fertilisation du sol, ont attiré notre attention. Leur isolement, leur dénombrement et l'étude de leurs caractères ...culturaux et morphologiques ont révélé leur diversité et leur nombre élevé au niveau de ce produit. Les isolats sélectionnés CHI4, CPI3 et CEI2 ont montré une tolérance très importante aux trois types de stress étudiés en particulier la levure CEI2 qui résiste à un pH très acide (2,5), à une température élevée (42 °C) et à une concentration en NaCl de 600 mM. Les cultures du haricot sur différents supports contenant ou non des levures issues de compost nous a permis de mettre en évidence leur effet positif sur le poids sec de la plante étudiée (Phaseolus vulgaris) par une augmentation de 700 %, 500 % et 400 %, par rapport au sol, avec CEI2, CPI3 et CHI4 respectivement. Cette augmentation dépasse de 1,5 fois le compost de l'été à partir duquel on a isolé la levure CEI2, de 1,4 fois le compost du printemps à partir duquel on a isolé la levure CPI3 et de 2,7 fois le compost de l'hiver à partir duquel on a isolé la levure CHI4. Ces trois levures et en particulier la CEI2 sont donc intéressantes pour une éventuelle utilisation dans la Biofertilisation des sols et l'augmentation du rendement de cette légumineuse. Mais si le sol est très acide avec une température très élevée dépassant les 40°C, la levure CEI2 sera une bonne candidate par rapport aux deux autres.
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