Salinity substantially affects plant growth and crop productivity worldwide. Plants adopt several biochemical mechanisms including regulation of antioxidant biosynthesis to protect themselves against the toxic effects induced by the stress. One-year-old pistachio rootstock exhibiting different degrees of salinity tolerance were subjected to sodium chloride induced stress to identify genetic diversity among cultivated pistachio rootstock for their antioxidant responses, and to determine the correlation of these enzymes to salinity stress. Leaves and roots were harvested following NaCl-induced stress. The results showed that a higher concentration of NaCl treatment induced oxidative stress in the leaf tissue and to a lesser extent in the roots. Both tissues showed an increase in ascorbate peroxidase, superoxide dismutase, catalase, glutathione reductase, peroxidase, and malondialdehyde. Responses of antioxidant enzymes were cultivar dependent, as well as temporal and dependent on the salinity level. Linear and quadratic regression model analysis revealed significant correlation of enzyme activities to salinity treatment in both tissues. The variation in salinity tolerance reflected their capabilities in orchestrating antioxidant enzymes at the roots and harmonized across the cell membranes of the leaves. This study provides a better understanding of root and leaf coordination in regulating the antioxidant enzymes to NaCl induced oxidative stress.

The excess of the chemical fertilizers not only causes the environmental pollution but also has many deteriorating effects including global warming and alteration of soil microbial diversity. In conventional researches, chemical fertilizers and their concentrations are selected based on the knowledge of experts involved in the projects, which this kind of models are usually subjective. Therefore, the present study aimed to introduce the optimal concentrations of three macro elements including nitrogen (0, 100, and 200 g), potassium (0, 100, 200, and 300 g), and magnesium (0, 50, and 100 g) on fruit yield (FY), fruit length (FL), and number of rows per spike (NRPS) of greenhouse banana using analysis of variance (ANOVA) followed by post hoc LSD test and two well-known artificial neural networks (ANNs) including multilayer perceptron (MLP) and generalized regression neural network (GRNN). According to the results of ANOVA, the highest mean value of the FY was obtained with 200 g of N, 300 g of K, and 50 g of Mg. Based on the results of the present study, the both ANNs models had high predictive accuracy (R²= 0.66–0.99) in the both training and testing data for the FY, FL, and NRPS. However, the GRNN model had better performance than MLP model for modeling and predicting the three characters of greenhouse banana. Therefore, genetic algorithm (GA) was subjected to the GRNN model in order to find the optimal amounts of N, K, and Mg for achieving the high amounts of the FY, FL, and NRPS. The GRNN-GA hybrid model confirmed that high yield of the plant could be achieved by reducing chemical fertilizers including nitrogen, potassium, and magnesium by 65, 44, and 62%, respectively, in compared to traditional method.

In the present study, an eco-friendly process was made for the rapid synthesis of silver nanoparticles using aqueous leaf extract of Hibiscus sabdariffa. The process was characterized by Fourier Transform Infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible and X-ray diffraction (XRD). These green silver nanoparticles (NPs) were used for mitigating the adverse effects of salinity on seed germination and growth parameters in plants. Accordingly, two experiments were conducted. In the first experiment, seven concentrations of green silver NPs and nine levels of NaCl:CaCl were apptoed on seeds for germination, and their effects were evaluated. In the second experiment, three concentrations of green silver NPs and NaCl were hypothesized to affect plant growth parameters. Seed germination, plant height, leaf, and root fresh and dry weights, as well as relative water content (RWC), decreased significantly under salt stress. However, green silver NPs intervened by alleviating the adverse effects of stress. Accordingly, green silver NPs were beneficial due to (1) activation of the antioxidant system by enhancing antioxidant enzymes such as catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD), and superoxide dismutase (SOD); (2) increase in the amounts of proline, soluble sugars and carbohydrates for osmoprotection; (3) improvements in flavonoid and anthocyanin contents. Real-time PCR showed that flavonoid and anthocyanin contents increased because of higher expressions in chalcone synthase (CHS), flavanone 3‐hydroxylase (F3H), and anthocyanidin synthase (ANS) genes. In conclusion, green silver NPs offered an eco-friendly application for further research on agricultural development.