RESUMEN
Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a destructive disease that causes significant yield losses in wheat production worldwide, including in Egypt. The use of biocontrol agents is among the best eco-friendly management strategies to control this disease, as they are more sustainable and environmentally friendly than traditional chemical control methods. In a comparative analysis, antioxidant enzyme activity and various management approaches were compared with two bacterial biocontrol agents, Bacillus subtilis and Pseudomonas putida. This study showed the remarkable efficacy of endophytic bacteria, B. subtilis and P. putida, in mitigating wheat stripe rust infection across three wheat varieties, namely Misr1, Gimmeiza11, and Sids12. B. subtilis exhibited superior performance compared to P. putida, resulting in infection types of 1 and 2.66, respectively, following inoculation. The highest reduction rate was observed with Tilit fungicide (500 ppm), followed by B. subtilis and Salicylic acid (1000 ppm), respectively. Variations in wheat varieties' response to Pst infection were observed, with Misr1 exhibiting the lowest infection and Sids12 showing high susceptibility. Among the tested inducers, Salicylic acid demonstrated the greatest reduction in disease infection, followed by Indole acetic acid, while Oxalic acid exhibited the lowest decrease. Additionally, the study evaluated the activities of five antioxidant enzymes, including Catalase, Ascorbate peroxidase (APX), glutathione reductase (GR), Superoxide dismutase (SOD), and peroxidase (POX), in the wheat-stripe rust interaction under different integrated management approaches. The wheat variety Misr1 treated with Tilit (500 ppm), B. subtilis, Salicylic acid, Montoro (500 ppm), and P. putida exhibited the highest increase in all enzymatic activities. These findings provide valuable insights into the effectiveness of B. subtilis and P. putida as biocontrol agents for wheat stripe rust control in Egypt, emphasizing their potential role in sustainable, integrated, and environmentally friendly management practices.
RESUMEN
Onion (Allium cepa L.) which is belonging to the family Liliaceae, is one of the greatest vital crops field worldwide. In this current work, Stored, high throughput and green synthesized silver nanoparticles; AgNPs (2000 ppm) were used as an eco-friendly nano fertilizer for onion in field conditions. All state of art analysis (Uv-vis, TEM, SEM, particle size analyzer and zeta potential) were used to characterize the formed AgNPs. Twelve concentrations (from 5 to 100 ppm) of AgNPs, were applied to onion, in addition to, two commercial nano products as control; iron nanoparticles (FeNPs) and zinc nanoparticles (ZnNPs) (2000 and 2500 ppm, as recommended by the markets). All concentrations were prepared under optical conditions and were applied three times in open field in a randomized complete block design (RCBD) during both seasons 2017/2018 and 2018/2019 as foliar application for onion plants after 25, 40 and 55 days, directly after the first irrigation of the plant. To this end, the physio-biochemical parameters such as CO2 concentration, stomatal conductance and internal CO2 were calculated via steady-state porometer 11 (LICOR, LI-1600, Lincoln, NE, USA). After 120 days of growth sowing (DAS), yield components and quality were evaluated. Just after harvesting, onion was subjected to extraction using dichloromethane for further analysis. All extracts were analyzed using GC-MS under the optimum operational condition to calculate the different constituents. The obtained results designated that, foliar application using 20 ppm of AgNPs displayed the highest mean values of all morphological, yield, yield components and quality characters compared with other concentrations and also to the commercial products, that used very high doses ranged from 2000 to 2500 ppm that can lead to genotoxicity in term of mutations in future, for human health. In conclusion, AgNPs can be used as an eco-friendly nano fertilizer with a recommended dose of 20 ppm which is considered a safe dose to the environment and human health too, compared with the crazy doses of the available commercial products.