The physiological activities of streptothricin antibiotics were investigated, taking racemomycin-D as a representative of the group. It was found that racemomycin-D has insecticidal activity, ...fish-toxicity and inhibitory activity on plant growth. Firstly, racemomycin-D showed a weak but broad-spectrum insecticidal activity against the adults of Blattella germanica, Musca domestica, Nilaparvata lugens, Laodelphax striatella, and Plutella xylostella. A rather strong insecticidal effect on Culex pipiens molestus larvae was found, with mortalities of 90% and 15% at 10 ppm and 2 ppm, respectively. Though racemomycin-D showed no insecticidal effect against the larvae of Spodoptera litura, it showed inhibitory activity on feeding at a concentration of 300 ppm. Secondly, racemomycin-D was toxic to all the fish species examined, i. e., Misgurnus anguillicaudatus, Carassius auratus, and Oriziae latipes. Among these, racemomycin-D showed particularly strong toxicity against C. auratus with a TLm of 3.7 ppm (after 48 hr). Thirdly, racemomycin-D showed strong inhibitory activity on the growth of Brassica campestris L. subsp. Napus Hook fil et Anders var. nippo-okifera, Arctium Lappa L., Petrocelium sativum, and Raphanus sativus L. var. acanthiformis at a concentration of 500 ppm (with an inhibitory ratio of 0.1, relative to 1.0 for the control group).
•Oil Palm seeds are notorious for slow and unreliable germination.•Magnetic treatment stimulates imbibition of water.•Magnetic treatment stimulates germination in a very short time ...(30d).•Electromagnetic methods allow preparation of detailed dose response curves.•Large numbers of seeds can be processed.
Difficult-to-germinate seeds are a common plant conservation, plantation and biotechnological problem. Oil palm (Elaeis guineensis) seed germination takes 6 months to 1year with ≈40% failure rate. We investigated the affect of various electromagnetic DC field strengths on oil palm germination. Kernels imbibed water more effectively when exposed to a magnetic field. The kernels were divided into three groups. The first group (50) was soaked (imbibed) in distilled water (2h) with no exposure to applied magnetic fields (blank control). The second group was exposed to magnetic fields with intensities of 2.5mT, 5.0mT, 7.0mT, 9.0mT and 11.0mT for 1, 2, 3, 4 and 5h (Dry Treated Kernels, DTK). The same electromagnetic protocol was conducted on a third group but with kernels which were immersed in water (Magnetically-Treated-Water-Kernels, MTWK). 96% germination was achieved by day-30 for the MTWK treatment using 9.0mT for 4h: slightly lower results were found for DTK kernels. None of the controls germinated within 30days. Young oil palm seedlings kept in a shade house (≈110μmol quanta m−2s−1 PPFD) watered every day with MTW grew 3 times faster (3.1mmday−1) than controls watered using unmagnetised water.
Several reports of graphene oxide (GO) promoting plant growth have sparked interest in its potential applications in agroforestry. However, there are still some toxicity studies that have raised ...concerns about the biosafety of GO. These reports show conflicting results from different perspectives, such as plant physiology, biochemistry, cytology, and molecular biology, regarding the beneficial and detrimental effects of GO on plant growth. Seemingly inconsistent studies make it difficult to effectively apply GO in agroforestry. Therefore, it is crucial to review and analyze the current literature on the impacts of GO on plant growth and its physiological parameters. Here, the biological effects of GO on plant growth are summarized. It is proposed that an appropriate concentration of GO may be conducive to its positive effects, and the particle size of GO should be considered when GO is applied in agricultural applications. This review provides a comprehensive understanding of the effects of GO on plant growth to facilitate its safe and effective use.
Summer savory (
Satureja hortensis
L.) is most often used as a culinary herb, but it also has medicinal benefits. The extracts from control and irradiated savory were obtained by ultrasound ...extraction for 30 minutes in an ethanol — water (80:20, v/v) mixture. Polyphenolic compounds from savory were identified and characterized by high-performance liquid chromatography coupled with a photodiode array detector and mass spectrometer. The separation was performed using an Altima C18 column (100×3 mm, 3 μm) and as mobile phase two solvent mixture: A — acetonitrile and B — water-formic acid (99.9:0.1, v/v). Peaks were identified with authentic standards in accordance to retention time, UV spectra and molecular mass. It was identified as caffeic acid, rosmarinic acid, luteolin, naringenin and apigenin. A quantitative determination of polyphenolic compounds was performed applying the external standard method. Our study showed large quantitative differences between the control plant and the irradiated plant.
The present work reports the variation of the ascorbic acid content in leaves of parsley, dill and celery plants grown in microwave fields of two microwave frequency domains: GSM (mobile ...communication) and WLAN (wireless internet connection). The percentage increase in ascorbic acid content of irradiated plants reported to control plants was calculated. The ascorbic acid was identified and quantified by high-performance liquid chromatography (HPLC) and electrochemical methods. The experiments were performed on Grace Alltima C18 column (100 x 3 mm, 3 µm) thermostated at 30°C with gradient elution. The mobile phase used for chromatographic separation consists of 15 mM potassium phosphate buffer at pH 2.7 and methanol. Electrochemical experiments employed chronoamperometry using a typical three-electrode electrochemical cell. Amperometric measurements were carried out under magnetic stirring using 0.1 M phosphate buffer solution (pH 6.8) as supporting electrolyte. Our study showed different percentage increases in ascorbic acid content of microwave irradiated plants determined by HPLC and electrochemical method, respectively, with lowest values (6.8%, 11%) in parsley irradiated with WLAN frequency microwaves, and highest values (more than 200%) in celery irradiated with GSM frequency microwaves. Keywords: ascorbic acid, HPLC, chronoamperometry, microwave effects on plant growth, aromatic plants
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