No abstract

No abstract

Introduction. Zinc is one of the essential micronutrients for living organisms; so, the right performance of several enzymes depends on this element. This micronutrient is a regulator of phytohormones and chlorophyll synthesis, and also, it is an essential element for the carbohydrates’ metabolisms in plants. Considering the relatively high solubility of ZnO-NPs and also the ability of plants to uptake and accumulate these nanoparticles in their biomass, ZnO-NPs can be used as an effective nanofertilizer for plants’ growth. Methods. In the present study, zinc oxide nanoparticles synthesized using chemical method and the effect of ZnO-NPs (as a nanofertilizer) on seeds’ germination, seedlings’ rootlet, seedlings’ plumule, and seedling’s vigour index in two oilseed crops from the Brassicaceae family, including Brassica napus L. and Camelina sativa, were investigated. After treating the seeds with different concentrations of ZnO-NPs (from 0.1 to 1000 ppm) for 6 days, the germination percentage (GP) of each treatment was measured. Results. The results indicated an increase in GP for both plants treated with 10 ppm ZnO-NPs. For B. napus, the maximum GP occurred in treated seeds with 5 ppm ZnO-NPs which showed a 30% increase of GP compared with the control condition. For Camelina, this maximum GP was observed in 0.1 ppm concentration of ZnO-NPs which showed a 15% increase compared with the control condition. After the germination test, germinated seedlings were planted in Hoagland hydroponic solution and treated with ZnO-NPs again for a week. For both species, treatment with ZnO-NPs showed a great effect on rootlet growth, while the effects of these treatments on plumule were negligible. The maximum rootlet length was observed in treated B. napus seedlings with 5 ppm ZnO-NPs which showed a 32% increase in this parameter compared with the control condition. In contrast, the high concentrations of ZnO-NPs showed toxic effects on B. napus seedlings’ rootlets. Results showed a 41% decrease in B. napus seedlings treated with 50 ppm ZnO-NPs compared with control seedlings. Similar results were observed in the treated seedlings of Camelina. For Camelina seedlings treated with 1 ppm ZnO-NPs, 15% increase in rootlets’ length was observed, while treated Camelina seedlings with 50 ppm ZnO-NPs showed a 68% decrease in rootlet length compared with the control condition. The results of this study indicated the potential of using ZnO-NPs as nanofertilizer for B. napus and Camelina in low concentrations (lower than 10 ppm). In addition, these results suggest the toxicity effects of these nanoparticles on both species in concentrations higher than 50 ppm.

In order to determine the best hormone treatment for nonembryogenic and embryogenic calli induction, apical meristem of young corms derived from saffron (Crocus sativus L.) were cultured in solid LS medium supplemented with different concentration of two auxin (NAA and 2,4-D) and three cytokinin (BAP, Kin and 2ip) at 22°C in darkness. Statistical analysis using Kruskal-Wallis Test showed that treatment containing 2 mg/L NAA and BAP with highest Mean Rank had the beat effect on induction of nonembryogenic callus and treatment containing 1 mg/L 2, 4-D and BAP had the best effect on induction of embryogenic callus. The results obtained from counting number and viability of protoplasts isolated from embryogenic calli with homeocytometer and Trypan Blue under the enzyme solution consisting of MS medium with 0.1 % (w/v) Pectolyase Y-23, 1 % Cellulose R-10, 1% Deriselase, 0.1 % MES (2-Nmorpholino ethane sulfonic acid), and 0.3 M mannitol at pH 5.7 on a rotary shaker (200 rpm) at 25 °C in darkness for 4 time-term treatment (1.5, 3, 4 & 5 hour) indicated that after 3 h enzyme treatment, 40×10 5 protoplasts per 1 mL of suspension with 98 % viability obtained that were the best time-term treatment. Finally, in order to protect and maintain the viability of fragile protoplasts, Calsium-alginats beads were used for their immobilization.

No abstract