Early Sprouting and First Stages of Growth of Rice Seeds Exposed to a Magnetic Field

The effects of a stationary magnetic field on the germination of rice seeds (Oryza sativa, L.) and on the initial stages of growth of rice plants have been evaluated. In both tests, the seeds were exposed to one of two magnetic field strengths (125 or 250 mT) for different times (1 min, 10 min, 20 min, 1 h, 24 h, or chronic exposure) as 12 separate treatments (doses D1–D6 for 125 mT and doses D7–D12 for 250 mT). Nonexposed seeds were used as controls (C). The mean germination time (MGT) was significantly reduced compared to control when seeds were exposed to magnetic field (54.00 h for D5 and D11, and 58.56 h for control). The parameters T₁ and T₁₀, times required to obtain 1 and 10% of germinated seeds, were also reduced. The T₁₀ of control seeds was 44.40 h, while treatments D5, D6, D11, and D12 gave rise to values of 36.00, 36.96, 32.64, and 39.36 h, respectively. The higher germination rate of treated seeds obtained in the germination test is in agreement with the higher lengths and weights of rice plants exposed to a magnetic field recorded on the growth tests. All the parameters measured were over the control ones, although the highest lengths and weights of rice plants were obtained for chronic exposure to magnetic field (doses D6 and D12). Stem length of control plants (45.36 mm) measured at the tenth day was significantly lower than that obtained for doses D6 (58.58 mm) and D12 (80.63 mm); the same behavior was observed on total length, stem weight, and total weight. Our finding indicates that this type of magnetic treatment clearly affects germination and the first stages of growth of rice plants.     

旋转磁场对小麦种子萌发及幼苗生长的影响

以“淮麦19”小麦种子为研究对象,采用磁场强度为11 mT的旋转磁场进行处理,设定不同的时间梯度(10、20、30、60 min),以未经磁场处理的为对照,研究了不同处理时间下旋转磁场对小麦种子发芽指标及幼苗生理特性的影响。结果表明：旋转磁场处理对小麦种子萌发具有促进作用,不同处理时间下,种子的发芽势、发芽率、发芽指数均有显著提高,随着时间的增加呈现先上升后下降的趋势,以处理30 min为最高,分别比对照提高了8.24％、7.37％、11.24％。经旋转磁场处理后,小麦根系发达,根长、根数均显著高于对照;幼苗生长加快,株高除处理60 min外,其他处理均显著高于对照,以处理30 min为最大,高出对照11.13％;叶片数除处理10 min外,其他处理均高于对照,以处理30 min为最大,比对照高出38.89％,且差异显著。旋转磁场处理显著增加了小麦幼苗的物质积累,不同处理时间表现出不同的效果,对幼苗生物积累量影响最佳的是处理20 min。这说明旋转磁场处理提高了小麦种子的萌发能力,加快了小麦幼苗的生长速度。     

Extremely low frequency magnetic fields suppress the reduction of germination rate of Arabidopsis thaliana seeds kept in saturated humidity.

The effects of an extremely low frequency magnetic field (ELFMF) on the germination of plant seeds were examined. The decrease in the germination activity of the seeds of Arabidopsis thaliana WS kept in saturated humidity and high temperature (37 degrees C) was suppressed by the exposure to a 400 mT ELFMF.     

Extremely Low Frequency Magnetic Fields Suppress the Reduction of Germination Rate of Arabidopsis thaliana Seeds Kept in Saturated Humidity

The effects of an extremely low frequency magnetic field (ELFMF) on the germination of plant seeds were examined. The decrease in the germination activity of the seeds of Arabidopsis thaliana WS kept in saturated humidity and high temperature (37°C) was suppressed by the exposure to a 400 mT ELFMF.     

Influence of magnetopriming on germination,growth, physiology,oil and essential contents of cumin (Cuminum cyminum L.)

An environment friendly technique is desirable for enhancing of crop production. In this study, seeds of cumin (Cuminum cyminum L.) Yazd accession were treated with 0, 150 mT, 250 mT, 500 mT and 1 T magnetic field strengths for min and germination parameters were determined. All of the treatments improved germination parameters and seedling growth as compared with the control. However, 500 and 150 mT were the most effective treatments and thus selected for field studies. Seeds were exposed to 150 mT and 500 mT static magnetic field of strengths for 12 min, planted in the field during 2010–2012 in Isfahan, Iran. Static magnetic field treatment shortened the days to emergence, flowering and maturity, increased chlorophyll and reduced proline contents. Highest biological, seed and essential oil yield, oil content, and oil yield were recorded under 500 mT followed by 150 mT and control, respectively. The results suggested that the pretreatment of cumin seeds with static magnetic field can improve germination, growth and oil and essential contents of the cumin seed under the field.     

STIMULATION OF GERMINATION IN RICE (ORYZA SATIVA L.) BY A STATIC MAGNETIC FIELD

This study evaluates the percentage and rate of germination of rice (Oryza sativa L.) seeds, when exposed to magnetic treatment in laboratory conditions. The seeds were exposed to 150 and 250 mT magnetic fields both chronically and for 20 min after seeding. Nonexposed seeds were used as control. Chronic exposure to a 150-mT magnetic field increased (p < 0.05) both the rate and percentage of germination relative to nonexposed seeds (18% at 48 h). Significant differences were also obtained for seeds exposed to a 250-mT magnetic field for 20 min (12% at 48 h). Additionally, seeds were moistened with water magnetically treated by static and dynamic methods. Dynamic and static treatment of water improved the germination of seeds related to the control, but significant differences (p < 0.05) were only obtained for the dynamic method (16% at 48 h).     

Enhancement of germination, growth, and photosynthesis in soybean by pre-treatment of seeds with magnetic field

Experiments were conducted to study the effect of static magnetic fields on the seeds of soybean (Glycine max (L.) Merr. var: JS-335) by exposing the seeds to different magnetic field strengths from 0 to 300 mT in steps of 50 mT for 30, 60, and 90 min. Treatment with magnetic fields improved germination-related parameters like water uptake, speed of germination, seedling length, fresh weight, dry weight and vigor indices of soybean seeds under laboratory conditions. Improvement over untreated control was 5-42% for speed of germination, 4-73% for seedling length, 9-53% for fresh weight, 5-16% for dry weight, and 3-88% and 4-27% for vigor indices I and II, respectively. Treatment of 200 mT (60 min) and 150 mT (60 min), which were more effective than others in increasing most of the seedling parameters, were further explored for their effect on plant growth, leaf photosynthetic efficiency, and leaf protein content under field conditions. Among different growth parameters, leaf area, and leaf fresh weight showed maximum enhancement (more than twofold) in 1-month-old plants. Polyphasic chlorophyll a fluorescence (OJIP) transients from magnetically treated plants gave a higher fluorescence yield at the J-I-P phase. The total soluble protein map (SDS-polyacrylamide gel) of leaves showed increased intensities of the bands corresponding to a larger subunit (53 KDa) and smaller subunit (14 KDa) of Rubisco in the treated plants. We report here the beneficial effect of pre-sowing magnetic treatment for improving germination parameters and biomass accumulation in soybean.     

A STATIC MAGNETIC FIELD OF 125 mT STIMULATES THE INITIAL GROWTH STAGES OF BARLEY (Hordeum vulgare L.)

In this paper the influence of a stationary magnetic field on the initial stages of barley plant development was evaluated. A stationary magnetic field has a stimulating effect on the first stages of growth of barley seeds for all exposure times studied. When germinating barley seeds were subjected to a magnetic field of 125 mT for different times (1, 10, 20, and 60 min, 24 h, and chronic exposure), increases in length and weight were observed. Maximum increases in the measured parameters were obtained when the time of exposure to magnetic field was long (24 h and chronic); however, the exposure for a short time (1 min) had a similar effect on growth.     

Exposure of maize seeds to stationary magnetic fields: Effects on germination and early growth

The effect of the exposure of maize seeds to stationary magnetic fields on germination and early growth has been studied under laboratory conditions. Seeds were magnetically exposed to one of two magnetic field strengths, 125 or 250 mT for different periods of time. Mean germination time and the time required to obtain 10, 25, 50, 75 and 90% of seeds to germinate were calculated. The results showed a reduction of these parameters for most of magnetic treatments, therefore their rate of germination was increased.Growth data measured on the 7th and 10th day after seeding allowed us to corroborate the effect observed in germination tests. Treated plants grew higher and heavier than control; on the 10th day total length was greater than control plants exposed to stationary magnetic field, corresponding with increase of the total fresh weight. The greatest increases were obtained for plants continuously exposed to 125 or 250 mT.     

Exposure of seeds to static magnetic field enhances germination and early growth characteristics in chickpea (Cicer arietinum L.)

Seeds of chickpea (Cicer arietinum L.) were exposed in batches to static magnetic fields of strength from 0 to 250 mT in steps of 50 mT for 1-4 h in steps of 1 h for all fields. Results showed that magnetic field application enhanced seed performance in terms of laboratory germination, speed of germination, seedling length and seedling dry weight significantly compared to unexposed control. However, the response varied with field strength and duration of exposure without any particular trend. Among the various combinations of field strength and duration, 50 mT for 2 h, 100 mT for 1 h and 150 mT for 2 h exposures gave best results. Exposure of seeds to these three magnetic fields improved seed coat membrane integrity as it reduced the electrical conductivity of seed leachate. In soil, seeds exposed to these three treatments produced significantly increased seedling dry weights of 1-month-old plants. The root characteristics of the plants showed dramatic increase in root length, root surface area and root volume. The improved functional root parameters suggest that magnetically treated chickpea seeds may perform better under rainfed (un-irrigated) conditions where there is a restrictive soil moisture regime.     

Characteristics of low frequency magnetic field effect on swelling of wheat seeds at various stages]

Low-frequency magnetic field treatment (50 Hz, 30 mT, 15 min) of wheat seeds with a 50% germination efficiency during imbibition at the stage of root formation leads to a statistically significant increase in the number of seeds having sprouts, a still greater increase in the number of seeds having roots, and to an increase in the length of sprouts compared with the control and the seeds treated several hours later. In the last case, an increase in the germinating capacity with a considerably lesser effect on the number of seeds with roots was also observed. Prolonged treatment with the field during the second day of imbibition decreased reliably the length of sprouts with a weaker influence on the number of seeds with sprouts and roots. These data suggest the principal possibility of the effect of electromagnetic fields on the realization of the genetic program during the germination of wheat seeds.     

Improvement of the growth and yield of lettuce plants by non-uniform magnetic fields

Influence of pre-sowing magnetic treatments on plant growth and final yield of lettuce (cv. Black Seeded Simpson) were studied under organoponic conditions. Lettuce seeds were exposed to full-wave rectified sinusoidal non uniform magnetic fields (MFs) induced by an electromagnet at 120 mT (rms) for 3 min, 160 mT (rms) for 1 min, and 160 mT (rms) for 5 min. Non treated seeds were considered as controls. Plants were grown in experimental stonemasons (25.2 m(2)) of an organoponic and cultivated according to standard agricultural practices. During nursery and vegetative growth stages, samples were collected at regular intervals for growth analyses. At physiological maturity, the plants were harvested from each stonemason and the final yield and yield parameters were determined. In the nursery stage, the magnetic treatments induced a significant increase of root length and shoot height in plants derived from magnetically treated seeds. In the vegetative stage, the relative growth rates of plants derived from magnetically exposed seeds were greater than those shown by the control plants. At maturity stage, all magnetic treatments increased significantly (p < 0.05)--plant height, leaf area per plant, final yield per area, and fresh mass per plant--in comparison with the controls. Pre-sowing magnetic treatments would enhance the growth and final yield of lettuce crop.     

Pre-sowing magnetic treatments of tomato seeds increase the growth and yield of plants

The effects of pre-sowing magnetic treatments on growth and yield of tomato (cv Campbell-28) were investigated under field conditions. Tomato seeds were exposed to full-wave rectified sinusoidal non-uniform magnetic fields (MFs) induced by an electromagnet at 100 mT (rms) for 10 min and at 170 mT (rms) for 3 min. Non-treated seeds were considered as controls. Plants were grown in experimental plots (30.2 m(2)) and were cultivated according to standard agricultural practices. During the vegetative and generative growth stages, samples were collected at regular intervals for growth rate analyses, and the resistance of plants to geminivirus and early blight was evaluated. At physiological maturity, the plants were harvested from each plot and the yield and yield parameters were determined. In the vegetative stage, the treatments led to a significant increase in leaf area, leaf dry weight, and specific leaf area (SLA) per plant. Also, the leaf, stem, and root relative growth rates of plants derived from magnetically treated seeds were greater than those shown by the control plants. In the generative stage, leaf area per plant and relative growth rates of fruits from plants from magnetically exposed seeds were greater than those of the control plant fruits. At fruit maturity stage, all magnetic treatments increased significantly (P < .05) the mean fruit weight, the fruit yield per plant, the fruit yield per area, and the equatorial diameter of fruits in comparison with the controls. At the end of the experiment, total dry matter was significantly higher for plants from magnetically treated seeds than that of the controls. A significant delay in the appearance of first symptoms of geminivirus and early blight and a reduced infection rate of early blight were observed in the plants from exposed seeds to MFs. Pre-sowing magnetic treatments would enhance the growth and yield of tomato crop.     

Characterization of water distribution and activities of enzymes during germination in magnetically-exposed maize (Zea mays L) seeds

Magnetic seed treatment is one of the physical pre-sowing seed treatments to enhance the performance of crop plants. In our earlier experiment, we found significant increase in germination and vigour characteristics of maize (Zea mays L.) seeds subjected to magnetic fields. Among various combinations of magnetic field (MF) strength and duration, best results were obtained with MF of 100 mT for 2 h and 200 mT for 1 h exposure. The quicker germination in magnetically-exposed seeds might be due to greater activities of germination related enzymes, early hydration of membranes as well as greater molecular mobility of bulk and hydration water fractions. Thus, in the present study, changes in water uptake during imbibition and its distribution and activities of germinating enzymes during germination were investigated in maize seeds exposed to static magnetic fields of 100 and 200 mT for 2 and 1 h respectively by nuclear magnetic resonance (NMR) spectroscopy. The magnetically-exposed seed showed higher water uptake in phase II and III than unexposed seed. The longitudinal relaxation time T1 of seed water showed significantly higher values and hence greater molecular mobility of cellular water in magnetically-exposed seeds as compared to unexposed. Component analysis of T2 relaxation times revealed the early appearance of hydration water with least mobility and higher values of relaxation times of cytoplasmic bulk water and hydration water in magnetically-exposed over unexposed seeds. Activities of alpha-amylase, dehydorgenase and protease during germination were higher in magnetically-exposed seeds as compared to unexposed. The quicker germination in magnetically-exposed seeds might be due to greater activities of germination related enzymes, early hydration of membranes as well as greater molecular mobility of bulk and hydration water fractions.     

Effect of magnetic field on the accumulation of polyhydroxyalkanoates (PHAs) by microorganism in activated sludge

The effect of static magnetic field on polyhydroxyalkanoates (PHAs) syntheses by activated sludge under aerobic dynamic feeding (ADF) was evaluated in sequence batch reactors (SBR), with magnetic field intensities of 42, 21, 11 and 7 millitesla (mT) exposure in the feast, feast-famine and famine periods, respectively, and one control group without magnetic field exposure. Under each level of magnetic field intensity, the effect of magnetic field exposed in the famine period to PHAs syntheses was most significant in comparison with that in the feast or feast-famine period. Maximal hydroxybutyrate (HB) and (HV) yield occurred at 21 and 11 mT, respectively, and the minimal yield occurred at 42 mT during exposure in the famine period. The maximum biodegradable rate constant of PHA was noted at 11 mT during exposure in the famine period.     

Germination of soybean seeds exposed to the static/alternating magnetic field and algal extract

In the present study, the effect of the static and alternating magnetic field applied individually and in combination with an algal extract on the germination of soybean seeds (Glycine max (L.) Merrill) and chlorophyll content was examined. The exposure time of seeds to the static magnetic field was 3, 6, and 12 min, whereas to the alternating magnetic field was 1, 2.5, and 5 min. The static magnetic field was obtained by means of a permanent magnets system while the alternating magnetic field by means of magnetic coils. Algal extract was produced from a freshwater macroalga—Cladophora glomerata using ultrasound homogenizer. In the germination tests, 10% extract was applied to the paper substrate before sowing. This is the first study that compares the germination of soybean seeds exposed to the static and alternating magnetic field. The best effect on the germination and chlorophyll content in seedlings had synergistic action of the static magnetic field on seeds for 3 min applied together with the extract and alternating magnetic field used for 2.5 min. It is not possible to clearly state which magnetic field better stimulated the germination of seeds, but the chlorophyll content in seedlings was much higher for alternating magnetic field.     

Influence of nutrient availability and tree wildling density on nutrient uptake by Oxalis acetosella and Acer saccharum

The different weight-number strategies of seed production displayed by individuals of a Mediterranean fire-prone plant species (Cistus ladanifer) were investigated in relation to seed germination responses to pre-germination heating. A control (no heating), a high temperature during a short exposure time (100 degrees C during 5 min) and a high temperature during a long exposure time (100 degrees C during 15 min) were applied to seeds from different individual plants with different mean seed weight. These pre-germination treatments resemble natural germination scenarios for the studied species, absence of fire, typical Mediterranean shrub fire, and severe fire with high fuel load. Seed germination was related to heat treatments and seed mass. Seed heating increased the proportion of seeds germinating compared with the control treatment. Mean seed weight was positively correlated to the proportion of germinated seeds but only within heat treatments. These results suggest that in periods without fire, the relative contributions to the population dynamics are equal for all seeds, regardless of their mass, whereas heavier seeds would be the main contribution after wildfire events. Since lighter seeds can be produced in higher quantities than heavier ones within a given fruit, the number of seedlings produced per fruit depended strongly on the germination conditions. In the absence of wildfire, fruits producing lighter seeds gave rise to more seedlings; nevertheless, they were numerically exceeded by those producing heavy seeds after a wildfire. The implications of these results are discussed in relation to their consequences on the population dynamics of this species, considering also additional information on stand flammability and changes in seed mass with plant age.     

Effect of hot water and ultra violet radiation on the incidence of seedborne fungi of okra

Seed samples of okra (Abelmoschus esculentus (L.) Moench) variety Arka anamika were subjected to hot water treatment at 42, 52 and 62°C for a period of 30 min and UV light treatment for 10, 20, 30 min at 28 ± 2°C. Their efficacy was tested against some seedborne fungal species. Among them, seeds under hot water treatment at 52°C for 30 min and UV light at 20 min were found to be more effective in the improvement of crop, both in greenhouse and field conditions. Ultimately, there was increase in the total number of leaves, fruits, length of the fruit, girth and biomass of the plants. Apart from these the total number of seeds per fruit, 1000 seed weight and ascorbic acid content were also found to be enhanced. These treatments also reduced the incidence of mycoflora in the seeds and thereby enhanced the seed germination percentage and vigour index of the seedlings.     

Large granular lymphocytic (LGL) leukemia in rats exposed to intermittent 60 Hz magnetic fields

An animal model for large granular lymphocytic (LGL) leukemia in male Fischer 344 rats was utilized to determine whether magnetic field exposure can be shown to influence the progression of leukemia. We previously reported that exposure to continuous 60 Hz, 1 mT magnetic fields did not significantly alter the clinical progression of LGL leukemia in young male rats following injection of spleen cells from donor leukemic rats. Results presented here extend those studies with the following objectives: (a) to replicate the previous study of continuous 60 Hz magnetic field exposures, but using fewer LGL cells in the inoculum, and (b) to determine if intermittent 60 Hz magnetic fields can alter the clinical progression of leukemia. Rats were randomly assigned to four treatment groups (18/group) as follows: (1) 1 mT (10 G) continuous field, (2) 1 mT intermittent field (off/on at 3 min intervals), (3) ambient controls ( < 0.1 microT), and (4) positive control (5 Gy whole body irradiation from cobalt-60 four days prior to initiation of exposure). All rats were injected intraperitoneally with 2.2 x 10(6) fresh, viable LGL leukemic spleen cells at the beginning of the study. The fields were activated for 20 h per day, 7 days per week, and all exposure conditions were superimposed over the natural ambient magnetic field. The rats were weighed and palpated for splenomegaly weekly. Splenomegaly developed 9-11 weeks after transplantation of the leukemia cells. Hematological evaluations were performed at 6, 8, 10, 12, 14, and 16 weeks of exposure. Peripheral blood hemoglobin concentration, red blood cells, and packed cell volume declined, and total white blood cells and LGL cells increased dramatically in all treatment groups after onset of leukemia. Although the positive control group showed different body weight curves and developed signs of leukemia earlier than other groups, differences were not detected between exposure groups and ambient controls. Furthermore, there were no overall effects of magnetic fields on splenomegaly or survival in exposed animals. In addition, no significant and/or consistent differences were detected in hematological parameters between the magnetic field exposed and the ambient control groups.     

Contribution of a 300 kHz alternating magnetic field on magnetic hyperthermia treatment of HepG2 cells

We investigated the relative contributions of temperature and a 300 kHz alternating magnetic field (AMF) on magnetic hyperthermia treatment (MHT). Our system consisted of an induction coil, which generated AMF by electric current flow, and a newly developed, temperature‐controlled circulating water‐jacketed glass bottle placed inside the coil. The AMF generator operated at a frequency of 300 kHz with variable field strength ranging from 0 to 11 mT. Four treatment conditions were employed: (A) control (37 °C, 0 mT), (B) AMF exposure (37 °C, 11 mT), (C) hyperthermia (46 °C, 0 mT), and (D) hyperthermia plus AMF exposure (46 °C, 11 mT) for 30 min. Cell viability and apoptotic death rate were estimated. The relative contributions or interactions of hyperthermia (46 °C) and AMF (11 mT) on MHT were evaluated using 2 × 2 factorial experiment analysis. Group A was statistically different (P < 0.05) from each of the other treatments. The observed effects on both cell viability and apoptotic cell death were influenced by temperature (97.36% and 92.15%, respectively), AMF (1.78% and 4.99%, respectively), and the interactions between temperature and AMF (0.25% and 2.36%, respectively). Thus, the effect of hyperthermia was significant. Also, AMF exposure itself might play a role in MHT, although these observations were made in vitro. These findings suggest a possible presence of an AMF effect during clinical magnetic hyperthermia. Bioelectromagnetics 34:95–103, 2013. © 2012 Wiley Periodicals, Inc.