Background: Hemp (Cannabis sativa) is a crop with a wide range of uses, from the production of fiber and seeds to the secondary metabolites for medicinal purposes. In addition, it is characterized by high biomass yield and the ability to accumulate heavy metals, which makes this plant convenient for phytoremediation purposes. In this study, the effect of applying exogenous biodegradable chelating agents, citric acid (CA) and nitrilotriacetic acid (NTA), to zinc-contaminated soil on zinc (Zn) uptake by two industrial hemp varieties ‘Felina 32’ and ‘Monoica’ was studied. The effect of CA and NTA on available Zn in soils was investigated using an ‘in pot’ experiment under controlled conditions. The effect of both tested compounds on soil microbial activity was simultaneously evaluated. Results: After the application of NTA at a concentration of 5 mmol L−1, a > threefold increased accumulation of Zn in the above-ground parts was recorded in the ‘Felina 32’ variety. In the ‘Monoica’ variety, the levels of Zn in the above-ground parts were increased > twofold. NTA affected the soil microbiome negatively, causing decreased enzyme activity (in ‘Monoica’ planted soil) and induced respiration (in ‘Monoica’ and especially in ‘Felina 32’ planted soil). On the other hand, CA application did not lead to significantly increased Zn levels in any of the studied hemp varieties. Together with CA’s negative effects on some soil enzymes, CA enhanced urease activity, dehydrogenase and several respiration types for the ‘Felina 32’ variety and exerted less detrimental effect on the soil microbiome. No toxic effects from increased Zn uptake and accumulation in experimental plants were detected, accounting for the unchanged physiological stress markers (levels of photosynthetic pigments and proline in leaves, chlorophyll fluorescence parameters) and selected growth traits of the above-ground organs and root system. Conclusions: From the studied varieties, ‘Felina 32’ seems to be more suitable for Zn-phytoextraction because of its higher tolerance to increased Zn levels, higher biomass production and Zn accumulation capacity. Our results indicate the potential of using the ‘Felina 32’ variety in NTA-assisted Zn phytoextraction from contaminated soils. Graphical
10 March 2020 in International Journal of Environmental Research
Rice (Oryza sativa L.) is productively affected by different environmental factors, including biotic and abiotic stress. The objectives of this research were to evaluate the genetic distinction among Kurdish rice genotypes using the simple sequence repeats (SSRs) molecular markers and to perform in vitro tests to characterize the drought tolerance of six local rice genotypes. The polymorphic information content (PIC) varied from 0.38 to 0.84 with an average of 0.56. The genetic distance ranged from 0.33 to 0.88. Drought stress had a significant impact (p ≤ 0.05) on callus growth parameters. Enzymatic antioxidant systems were predicted and exhibited a significant variation. The findings revealed that proline levels increase in proportion to polyethylene glycol (PEG) concentrations. Kalar and Gwll Swr genotypes showed the worst performances in phenotypic and biochemical traits, while Choman and Shawre exhibited the best phenotypic and biochemical performances. A positive and substantial relationship between callus fresh weight (CFW) and callus dry weight (CDW) was found under stressful and optimized conditions. Callus induction (CI) was positively and significantly associated with the catalase activity (CAT) in all stressed treatments. Based on the results for callus growth and the biochemical parameters under stress conditions, a remarkable genotype distinction, based on the tolerance reaction, was noted as follows: PEG resistant > susceptible, Choman > Shawre > White Bazyan > Red Bazyan > Gwll Swr > Kalar. The CI and CAT characteristics were considered as reliable predictors of drought tolerance in rice genotypes.
Despite current efforts to minimize the impact of industry on ecosystems, the environment is polluted by a range of foreign substances, that can have a negative impact on the living organisms. Examples of widely studied substances are polycyclic aromatic hydrocarbons (PAHs) and recently,...
Cold atmospheric plasma (CAP) is an emerging, chemical-free technology with significant potential to enhance crop performance. This study investigates the impact of direct plasma treatment on barley (Hordeum vulgare) seeds...