تقدير فعالية إنزيم (Nitrate reductase)‎ باستخدام دقائق الفضة النانوية المخلقة حيويا من الفطرين (Pleurotus pulmonarius)‎ و (Pleurotus ostreatus var ostreatus)‎ و تأثيرها على الفطر (Pythium aphanidermatum)‎

Abstract EN

This study was conducted in the laboratories of the Plant Protection Department, College of Agriculture at Tikrit University during the season 2018/2019.

The study aimed at studying the effectiveness of nitrate reductase using four concentrations (0.5, 1.0, 1.5, and 2.0) mmol of biosynthetic silver nanoparticles created from the fungi Pleurotus pulmonarius and Pleurotus ostreatus var ostreatus.

each fungus has four parts, including the filtrate of the fungus, the biomass, the hot and cold aqueous extract of the biomass of the fungus and its effect on Pythium aphanidermatum.

All the concentrations and types of the prepared silver nanoparticles showed the highest efficacy of the nitrate reductase enzyme compared to the control.

The highest activity was obtained at the concentration of 1.5 mmol in fungi filtrates, it was 0.65 and 0.66 units/ml for fungi p.

pulmonarius and p.ostreatus var ostreatus, followed by the treatment consisting of cold aqueous extract of the same concentration which reached 0.55 and 0.56 units/ml, respectively with no significant differences between them.

As for the treatment consisting of the fungus filtrate, this showed a significant difference with the rest of the treatments: The highest enzymatic activity of the fungi reached 0.32 and 0.43 units/ml respectively, compared with the treatment of hot water extract, which showed the lowest enzymatic activity, reaching 0.11 and 0.24 units/ml.

The laboratory results did not show significant differences of silver nanoparticles in wheat seeds germination (Variety Sham6) for all concentrations and types of nanoparticles prepared.

Whereas the highest germination percentage (97.38%) was for Pythium aphanidermatum biomass while P.ostreatus var ostreatus had highest germination percentage for cold aqueous extract which reached 97.20%.