فریده بهبودی

To evaluate the effect of chitosan NPs on wheat under late season drought stress, a factorial experiment was performed based on a randomized complete block design in three replications in pot conditions at Tarbiat Modares University in 2015. The experimental factors included the NPs concentrations (0, 30, 60 and 90 mg.L-1), application methods (foliar and soil application) and irrigation regimes (normal irrigation and removal of irrigation 15 days after pollination). Experimental procedure includes planting seeds and then prepared chitosan NPs suspension added to them through soil and foliar application in three stages (tillering, stem elongation and heading). Results indicated that the drought stress significantly decreased amount of carotenoid, chlorophyll a, b, total, photosynthesis, stomatal conductance, transpiration, yield, 1000- grain weight as well as biomass and increased intercellular CO2 concentration (Ci). In most studied traits, no significant difference was observed between consumption methods of nanoparticles. In both irrigation regimes, applying NPs especially concentration of 60 and 90 mg.L-1 significantly improved the majority of studied traits. In general, application of chitosan NPs reduced negative effects of drought stress in wheat plants and improved growth.

Chitosan is a glucosamine polysaccharide deacetylated form of chitin species and could be used as biotic elicitor to improve secondary metabolites and as a fertilizer it controls the release of chemical compounds of toxins and stimulates germination and plant growth. Thus, to evaluate the effect of chitosan NPs on barley plants under late season drought stress, a factorial pot experiment was performed based on a randomized complete block design with three replications. The experimental factors were NPs concentrations at 4 levels (0, 30, 60 and 90 ppm), method of usage at 2 levels (foliar and soil application) and irrigation regimes at 2 levels (normal irrigation and with-holding irrigation 15 days after pollination). Experimental procedure consisted of planting seeds, preparing chitosan NPs solution, and using solutions through soil and foliar application at three plant growth stages (tillering, stem elongation and heading). Results indicated that drought stress significantly decreased contents of carotenoid, chlorophyll a, the chlorophyll b, the total chlorophyll, rate of photosynthesis, stomatal conductance, transpiration, grain yield, as well as, biomass. Results also showed that contents of soluble carbohydrate, glucose, sucrose, fructose, intercellular CO2 concentration (Ci) and photosynthetic water use efficiency (WUE) were increased. Also, under both irrigation regimes, application of chitosan NPs significantly increased the chlorophyll a, the chlorophyll b, the soluble chlorophyll and the glucose. Application of 60 and 90 ppm NPs significantly increased grain yield as compared to that of control. Signifficant diffrences for some traits under study between two usage methods of NPs were not observed. In general, application of chitosan NPs reduced negative effects of drought stress for barley plants and improved its growth and seed yield.

In order to study the effect of vermicompost produced from cow manure impregnated to copper oxide and zinc oxide nanoparticles on some properties of wax bean crop (Vigna unguiculata), an experiment factorial were done based on a randomized complete block design in three replications. The experiment factors were as follows: nanoparticles (0, 0.4, 0.8 and 1.2 g/kg weight of substrate), vermicompost (2.5, 5 and 7.5 g/kg weight of substrate) and kind of nanoparticles (copper oxide and zinc oxide). After preparation of substrates, to any one of them was added adult worm Eisenia fetida and after a week were added nanoparticles to substrate as a solution. After three months, vermicompost prepared according to the weight of cultivation substrate was cultivated with mix soil and grain of wax bean as a wet planting. Results showed with increasing in both nanoparticles decreased spad leaves chlorophyll, number grain in pod, number of pod in bush, weight of pod, pod length, weight of hundred grains, grain yield, biological yield, harvest index, stem length and grain protein and increased concentration copper and zinc in grain. In similar level nanoparticles (except first level), spad leaves chlorophyll, number of pods, weight of hundred grains, grain yield, stem length and pod length in zinc oxide nanoparticles were more than copperoxide nanoparticles. In similar level nanoparticles and vermicompost accumulation of zinc in grain was more than copper. With comsumption of copper oxide nanoparticles, grain yield decreased 66 percent and With comsumption of zinc oxide nanoparticles, grain yield decreased 35 percent.

In order to study the effect of vermicompost containing copper oxide and zinc oxide nanoparticles on was beans, in an experiment factorial were done based on a randomized complete block design in three replications. The experiment treatment were as follows: nanoparticles in 4 levels (0, 0.4, 0.8 and 1.2 g/kg weight of substrate), vermicompost in 3 levels (2.5, 5 and 7.5 g/kg-1 weight of substrate) and kind of nanoparticles in 2 levels (copper oxide and zinc oxide). After preparation of substrates, to any one of them was added adult worm Eisenia fetida and after a week were added nanoparticles to substrate as a solution. After three months, vermicompost prepared according to the weight of cultivation substrate was cultivated with mix soil and wax bean as a wet planting. Results showed, with increasing copper oxide and zinc oxide nanoparticles decreased pod length, number of pod in bush, biological yield, grain yield, harvest index and grain protein and increased concentration copper and zinc in grain. In similar level nanoparticles (except first level), pod length, number of pod in bush, grain yield, weight of hundred grains, stem length and harvest index in zinc oxide nanoparticles were more than copper oxide nanoparticles.The least pod length, number of pod in bush, weight of pod, grain yield and harvest index obtained in forth level copper oxide nanoparticles. Also absorbtion and accumulation of zinc oxide nanoparticles in grain was more than copper oxide nanoparticles.