Titanium (Ti) is a very interesting chemical element, especially physiologically. Although Ti is not toxic for animals and humans, its effects on plants show remarkable concentration dependence. Whereas for plants, it shows beneficial effects on various physiological parameters at low doses. This study was conducted to evaluate the effect of bulk and nanoparticles titanium foliar application on some agronomic traits, seed gluten and starch contents of wheat under water deficit stress conditions during 2010-2011 growing seasons. The experimental design was randomized in complete blocks arranged in split-split plots with four replications. The factors included normal irrigation, water deficit stress (irrigation withholding at two growing stages of stem elongation and flowering), two growing stages for water deficit stress induction and titanium applications, five titanium concentrations, sources including control of titanium oxide (bulk), and three concentrations of 0.01%, 0.02%, and 0.03% of titanium dioxide nanoparticles. Plant height, ear weight, ear number, seed number, 1000-seed weight, final yield, biomass, harvest index, gluten, and starch contents were assayed. The results showed that water deficit stress caused significant decrease in plant growth, yield and yield components. In addition, among the different titanium treatments, titanium dioxide nanoparticles at 0.02% increased almost all agronomic traits including gluten and starch content. Thus, the application of titanium dioxide nanoparticles under conditions of water deficit stress is recommended.

Tests were done on the effects of treatments of titanium dioxide spray on corn (Zea mays L.). The study was conducted as a factorial experiment in a randomized complete block design with four replications. Treatments consisted of two factors; the first factor was stage of plant growth that spraying was applied (vegetative stage, appearance of male flowers and female flowers); and the second factor was that of different concentrations of titanium dioxide nanoparticles (Tio2) that consisted of spray with water (control), titanium dioxide or bulk, nano titanium dioxide at concentrations of 0.01% and 0.03%. Results showed that effect of nano Tio2 was significant on chlorophyll content (a and b), total chlorophyll (a + b), chlorophyll a/b, carotenoids and anthocyanins. The maximum amount of pigment was recorded from the treatment of nano Tio2 spray at the reproductive stage (appearance of male and female flowers) in comparison with control. Thus, an application of nanoparticles (nanao Tio2) can facilitate an increase in crop yield, especially corn yield.

To assess the response of promising safflower genotypes to late-season drought stress in delayed planting conditions, an experiment was conducted in two years (2016–2017 and 2017–2018) in Iran. The irrigation regime was specified in two levels, including normal irrigation and irrigation cut off in the seed filling stage in main plots, and five safflower genotypes, including Soffe, Goldasht, Golmehr, Padideh, and Parnian were categorized in subplots. Applied drought stress significantly reduced the seed yield and yield components of all genotypes, which accompanied with a substantial decrease in oil content and oil yield of all genotypes. However, the highest seed and oil yield in drought stress conditions obtained in the Parnian genotype by value 2338 and 561 kg/ha, respectively. Moreover, a significant drought-induced increase in palmitic, stearic, and oleic acids, as well as a decrease in linoleic acid content, was observed in all genotypes. Parnian genotype with high unsaturated fatty acids content (90.9%) and the minimum amount of saturated fatty acids (8.7%) might be a promising genotype to starting a formal crop improvement program to achieve more drought-tolerant safflower genotype.

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In order to investigate the composition of borage (Borago officinalis L.) seed oil, this research was performed under the field conditions at Shahriyar and Garmsar zones, Iran during the 2012 planting year. The oil yield of borage was 31.46% and 33.7% at Shahriyar and Garmsar zone, respectively, and nine and eight fatty acids were identified in the seed oil of borage at Shahriyar and Garmsar, respectively - palmitic, linoleic, stearic and γ-linolenic acids were dominant in the seed oil of borage from both zones. Unsaturated fatty acid content was more than the saturated fatty acids in both zones. The ratio of linoleic acid and α-linolenic acid in the borage cultivated at Shahriyar and Garmsar zones was 2.13 and 2.29. The fatty acid profile of Garmsar borage, oleic and oleic/linoleic acid ratio, increased. Locations with different ecological conditions resulted in changes in both seed oil content and fatty acid profile of borage.

Tests were done on the effects of titanium dioxide spray on Pinto bean (Phaseolus vulgaris L. c.v 'c.o.s.16'). The study was conducted as a factorial experiment in a randomized complete block design with four replications for two years (2014 -2015). Treatments consisted of two factors; the first factor was stage of plant growth that spraying was applied (rapid vegetative growth, flowering and pod filling); and the second factor was that of different concentrations of titanium dioxide nanoparticles (TiO 2 ) that consisted of spray with water (control), nano titanium dioxide at concentrations of 0.01%, 0.02%, 0.03% and 0.05%. Activity of guaiacol peroxidase (GPX), activity of superoxide dismutase (SOD), activity of catalase (CAT), activity of peroxidase (POD), malonyldialdehyde (MDA) Content and 8-deoxy-2-hydroxyguanosine (8-OHDG) content were assayed. Results showed that effect of nano TiO 2 was significant on activity of superoxide dismutase (SOD), activity of catalase (CAT), activity of peroxidase (POD), malonyldialdehyde (MDA) Content and 8-deoxy-2-hydroxyguanosine (8-OHDG) content. Results of combined analysis of variance showed that the effect year significantly affected on SOD and 8-OH-2-DG (P ≤ 0.05). The effect of different amounts of titanium dioxide nanoparticles (TiO 2 ) significantly affected (P ≤ 0.05) on MDA and 8-OH-2-DG. The effects of different amounts of titanium dioxide nanoparticles and year were significant on SOD, POD, MDA and the amount of 8-deoxy-2-hydroxyguanosine in P ≤ 0.05. None of the physiological traits were affected by spraying of nano titanium dioxide. The effects of TiO 2 nanoparticles times of spraying and year were significant on SOD, CAT and 8-deoxy-2-hydroxyguanosine (P ≤ 0.05). Interaction effects of nano TiO 2 concentrations × nano TiO 2 spraying times did not have a significant impact on SOD, CAT, POD, GPX, MDA and 8-OH-2-DG. Although, all trait were affected by interaction effects of year × nano TiO 2 concentrations × nano TiO 2 spraying times with the exception of GPX (P ≤ 0.05).

ABSTRACT. In order to investigate the effect of exogenous application of nanoTiO 2 on annual medic, a field study was conducted in a factorial design based on randomized complete blocks with four replications. The experimental treatments included six concentrations of nano-TiO 2 (Control, 0.01%, 0.02%, 0.03%, 0.04%, 0.06% g/l) and spraying at two growing stages (pod stage and 10% flowering stage). Results showed that the effects of nanoTiO 2 and spraying times on dry forage yield were significant (p<0.01). Nano-TiO 2 spray appear to influence the malone dialdehyde (MDA) content (p<0.01). With increasing concentrations of nano-TiO 2 the values of aforementioned measured variable significantly decreased. The activities of antioxidant enzymes, including catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) were affected by nanoparticle (p<0.01) and spraying times (p<0.01), as well as their interactive effect of two mentioned factors were significant in terms of guaiacol peroxidase (GPX) (p<0.01) activity and dry forage yield. Among different concentrations of nanoTiO 2 , 0.04% and 0.06% have the best effect on all traits. Totally, treatment with nanoTiO 2 were more effective in the pod stage, compared to 10% flowering stage.

This study was done to evaluate the effect of methanol and nano TiO2 foliar application on photosynthetic apparatus, anthocyanin and changes of nitrate reductase in borage (Borago officinalis L.) under deficit irrigation. Tests were done as a split factorial experiment set up as a completely randomized block design with four replications, in the year 2012, at Shahriyar City, Iran. Irrigation conditions were the factors tested in the main plots: deficit irrigation condition (irrigation every 7 days) and irrigation every 14 days. Methanol solutions 0 (control or sprayed with water), 15%, 35% and 45% (v/v) and, nanoTiO2 treatment (0 or control and nano TiO2 at concentrations of 0.01%, 0.03% and 0.05%) were tested in the sub plots. Plant characteristics under evaluation were those of; chlorophyll (Chl) a,b and total chlorophyll, Spad value, net photosynthetic rate, rubisco carboxylase activity, anthocyanin and nitrate reductase enzyme (NR). Also evaluated were the effects of interaction of deficit irrigation and methanol on all measured traits, and results determined the effect as significant with the exception of NR and interactions of deficit irrigation and nano TiO2 on all measured traits. Test results showed that maximum amount of traits at deficit irrigation was achieved by spraying with 45% v/v oncentration of methanol and nano Tio2 at the concentration of 0.05%. But the best treatments under normal irrigation were 15% v/v of methanol and 0.03% of nano Tio2. but at the methanol concentration of 45% and non-application of nano Tio2 under normal irrigation had the least effect. In summary, results of these tests determined that application of methanol and nano Tio2, can promote plant resistance to drought stress (particularly borage plants).