Medicinal Plants
Tala Nikbin; Fatemeh Nejadhabibvash
Abstract
Purpose: Nowadays, heavy metal pollution of soils has become a serious environmental concern and a potential threat to human health. Peppermint (Mentha piperita L.) is a medicinal and aromatic plant belonging to Lamiaceae family that its essential oil is used in different pharmaceutical industries. This ...
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Purpose: Nowadays, heavy metal pollution of soils has become a serious environmental concern and a potential threat to human health. Peppermint (Mentha piperita L.) is a medicinal and aromatic plant belonging to Lamiaceae family that its essential oil is used in different pharmaceutical industries. This study focused on the effects of arbuscular mycorrhizal fungi (AMF) and different concentrations of titanium dioxide nanoparticles (TiO2 NPs) addition on the growth, absorption of macronutrients, migration and bioaccumulation of cadmium in soil- peppermint system. Research Method: A factorial experiment was conducted in a completely randomized design with three factors. The first factor was TiO2 NPs (0, 200, and 300 mg/kg), the second factor included Cd-spiked soil (0 and 50 mg/kg soil) and third Trichoderma harzianum. Findings: Our results showed cadmium caused negative effects on the growth of peppermint except for shoot and root length. The concentration of all the nutrients assessed (nitrogen and phosphorus) decreased in the presence of cadmium. Mycorrhization under cadmium stress conditions significantly increased nitrogen concentration in roots and shoots by 15% and 3%, respectively, respect to Cd treatment group. Following mycorrhizal inoculation under cadmium stress conditions, phosphorus concentration significantly increased in roots and shoots by 33% and 12%, respectively, respect to Cd treatment group. Similarly, application of TiO2 nanoparticles at 200 mg/Kg and 300 mg/Kg concentrations alone and in combination with mycorrhizal soil amendments in stress as well as non-stress conditions effectively enhanced nutrient acquisition. With the addition of TiO2 NPs and mycorrhiza to soil, the phytoavailability and uptake of Cd by peppermint roots increased. Research limitations: There was no limitation. Originality/Value: Our research demonstrates that applying AMF and TiO2 NPs could be a sustainable approach to enhancing growth parameters of peppermint plants under Cd stress by improving nutrient acquisition and immobilizing the heavy metal Cd. The results obtained here can provide scientific data for the use of Mentha piperita L. in the remediation of Cd-contaminated soil.
Medicinal Plants
Elahe Ghafourian Hozouri Esfahan; Majid Azizi; Hassan Rakhshandeh; Hamid Sadeghian
Abstract
Purpose: Due to the short-day nature of the velvet bean, which triggers flowering in the autumn with decreasing day length, its production in temperate and high-latitude regions under greenhouse conditions requires modifications in its flowering and fruiting habits. Therefore, this study aimed to optimize ...
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Purpose: Due to the short-day nature of the velvet bean, which triggers flowering in the autumn with decreasing day length, its production in temperate and high-latitude regions under greenhouse conditions requires modifications in its flowering and fruiting habits. Therefore, this study aimed to optimize L-DOPA production by investigating photoperiod changes and hormonal regulation to encourage flowering and fruiting under greenhouse conditions. Research Method: Treatments included photoperiod at two levels (13-hour darkness and natural day length) as the first factor and growth regulators at seven levels (50 and 100 mg of gibberellin, 20 and 50 mg of paclobutrazol, 50 and 100 mg of cytokinin, and a control treatment) as the second factor. Findings: the effects of photoperiod, growth regulators, and their interaction were significant for all traits except for internode length. The natural light treatment resulted in a 3% delay in flowering compared to the 13-hour dark treatment, whereas the 13-hour dark treatment exhibited higher fruit weight, seed yield, and L-DOPA content (18%) compared to the natural light. Moreover, the application of 50 mg paclobutrazol reduced the days to flowering by 55 days compared to the control. On the other hand, the 50 mg paclobutrazol treatment showed significant increases in fruit weight (59%), seed yield (65%), and L-DOPA content (31%) compared to the control. Research limitations: No limitations were found. Originality/Value: Overall, extending the dark period improved velvet beans' yield and yield components. Furthermore, paclobutrazol enhanced yield more effectively than gibberellin and cytokinin. Based on the experiment, the best treatment for achieving maximum quantitative yield and L-DOPA content was 13-hour darkness combined with 50 mg of paclobutrazol.
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