Despite the toxicity of microplastics (MPs) in freshwater fish has been demonstrated in previous studies, their effects when mixed with other pollutants (organic and inorganic) are poorly understood. Thus, we aimed to test the hypothesis that the association of polyethylene MPs (PE-MPs) to a mix of emerging pollutants induces more adverse genotoxic, mutagenic, and redox unbalance effects in adult zebrafish (Danio rerio), after 15 days of exposure. Although the accumulation of MPs in animals was greater in animals exposed to PE-MPs alone, erythrocyte DNA damage (comet assay) and the frequency of erythrocytic nuclear abnormalities (ENAs) evidenced in zebrafish exposed to PE-MPs alone were as pronounced as those observed in animals exposed to the mix of pollutant (alone or in combination with MPs), which constitutes the big picture of the current study. Moreover, we noticed that such effects were associated with an imbalance between pro-and antioxidant metabolism in animals, whose activity of superoxide dismutase (SOD) and catalase (CAT) was assessed in different organs which were not sufficient to counterbalance the production of reactive oxygen species [hydrogen peroxide (H₂O₂)] and nitrogen [nitric oxide (NO)] evaluated. The principal component analysis (PCA) also revealed that while the antioxidant activity was more pronounced in the brain and liver of animals, the highest production of H₂O₂ was perceived in the gills and muscles, suggesting that the biochemical response of the animals was organ-dependent. Thus, the present study did not demonstrate antagonistic, synergistic, or additive effects on animals exposed to the combination between PE-MPs and a mix of pollutants in the zebrafish, which reinforces the theory that interactions between pollutants in aquatic ecosystems may be as complex as their effects on freshwater ichthyofauna.

There have been significant impacts of the current COVID-19 pandemic on society including high health and economic costs. However, little is known about the potential ecological risks of this virus despite its presence in freshwater systems. In this study, we aimed to evaluate the exposure of Poecilia reticulata juveniles to two peptides derived from Spike protein of SARS-CoV-2, which was synthesized in the laboratory (named PSPD-2002 and PSPD-2003). For this, the animals were exposed for 35 days to the peptides at a concentration of 40 µg/L and different toxicity biomarkers were assessed. Our data indicated that the peptides were able to induce anxiety-like behavior in the open field test and increased acetylcholinesterase (AChE) activity. The biometric evaluation also revealed that the animals exposed to the peptides displayed alterations in the pattern of growth/development. Furthermore, the increased activity of superoxide dismutase (SOD) and catalase (CAT) enzymes were accompanied by increased levels of malondialdehyde (MDA), reactive oxygen species (ROS) and hydrogen peroxide (H₂O₂), which suggests a redox imbalance induced by SARS-CoV-2 spike protein peptides. Moreover, molecular docking analysis suggested a strong interaction of the peptides with the enzymes AChE, SOD and CAT, allowing us to infer that the observed effects are related to the direct action of the peptides on the functionality of these enzymes. Consequently, our study provided evidence that the presence of SARS-CoV-2 viral particles in the freshwater ecosystems offer a health risk to fish and other aquatic organisms.

Intercropping system has been reported to enhance quality and yield obtained per unit area.Therefore,the current study was carried out to assess the impact of intercropping of Zucchini or broad beans with strawberry and also, intercropping (IC) Zucchini with broad beans on growth, quality, yield and the economic viability of the studied crops in the mixed IC, compared to the mono-cropping of these crops. A field experiment was carried out during 2017- 2018 and 2018-2019 . According to results of this study, intercropping of strawberry with broad beans achieved significantly the highest levels of anthocyanin content in strawberry fruits compared to the other treatments in both seasons. Maximum yield of strawberry crop was obtained from sole cropping as well as that obtained from strawberry-broad beans intercropping. Intercropping of Zucchini with broad beans resulted in significantly higher yields of both crops as compared with their sole cropping. Yield of broad bean and Zucchini increased by 18.1% and 26.9 % respectively as compared with their sole cropping which indicate yielding efficiency enhancement as a result of intercropping. Land equivalent ratio (LER) of strawberry- Zucchini intercropping was, on average1.2 for both years. Whereas, with regard to strawberry-broad beans intercropping was, on average for1.3 for both years, while it was 2.45 when Intercropping Zucchini with broad bean. Intercropping Zucchini with broad bean gave the highest relative yield for both of them compared with the other treatments and also, the highest monetary advantage index (MAI)

In the present investigation, effect of calcium chloride (CaCl2) used as foliar application (0, 10, 20 mM) was studied on morphological, yield, and quality of lettuce (Romaine and Green Waves cultivars) during 2017/2018 and 2018/2019 seasons. Our results indicated that, foliar spray of calcium chloride either at 10 or 20 mM significantly increased vegetative growth and yield parameters i.e., leaf number per plant, fresh and dry leaf weight compared to control treatment. Also, foliar spray of calcium chloride resulted in a significant increase in yield and quality parameters i.e., TSS, chlorophyll content and Vitamin C. ‘Romaine’ cultivar was significantly superior to ‘Green Waves’ cvs in plant height, fresh and dry weight of the leaves, TSS and chlorophyll content. However, there was no significant difference in vitamin C content between the two tested cultivars. ‘Green waves’ cv. sprayed with 20 mM CaCl2 gave the highest significant leaf number per plant. Fresh and dry leaf weight of ‘Romaine’cv recorded the highest values when the plants were sprayed with 20 mM CaCl2 in both seasons., In the first season, ‘Romaine’cv sprayed with 20 mM of CaCl2 produced the highest total yield, while the highest total yield in the second season was obtained from plants of both tested cvs sprayed with 20 mM CaCl2. ‘Romaine’ cultivar treated with 20 mM of calcium chloride as foliar application had the highest TSS and chlorophyll content. Fascinatingly, high association existed between total yield and all studied traits, except leaf number per plant. Overall results suggest applying calcium chloride as foliar application at 20 mM for improving yield quantity and quality in both ‘Romaine’ and ‘Green Waves’ cultivars.