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1.
Plant stress caused by exposure to magnetic fields （MF） induces modifications at molecular level, particularly in DNA synthesis, structure, and function. The objective of this study was to determine the effect of various doses of non-ionizing radiation of magnetic field on date palm （Phoenix dactylifera L.） based on DNA content. Date palm seedlings （cv. Khalas） established for 2 weeks on filter paper were subjected to static magnetic field and alternating magnetic field. Static magnetic fields （SMF） were applied at 10, 50 and 100 mT for 30, 60, 120, 180, 240 and 360 min; while alternating magnetic field applied by magnetic resonance imaging （MRI） at 1500 mT for 1, 5, 10 and 15 min. The seedlings were grown in potting soil following exposure for 4 weeks after which DNA was extracted from leaves and its content was determined. Generally, the exposure to magnetic field caused reduction in the content of DNA. The lowest exposure time tested, 30 rain, was sufficient to induce reduction in DNA content. This was true even at the lowest intensity, 10 mT. This dosage caused the DNA content to decrease from 49 ~tg/g to 45 pg/g. Further, increase of the exposure duration to 60 min caused significant reduction in the DNA content, 36 μg/g. At intensities higher than 10 mT, DNA content decreased significantly even at the shortest exposure of 30 min. At 50 and 100 mT, significant decrease in DNA content was also noticed in response to 30 min exposure; whereas the level of DNA increased after 1 min of MRI exposure to 52 ~g/g, then decreased after 5 min to 46 ~g/g. However, longer durations caused no further decrease in the DNA content. These observations indicate that magnetic fields interact with DNA processes, probably by inhibiting synthesis or stimulating degradation of DNA. This response merits further exploration as a mutational agent for date palm genetic manipulation.  相似文献   

2.
[Objective]The aim of the research was to provide reference for reasonable application of nitrogen fertilizer for high yield cultivation of hybrid rape cultivar Youyan 9 and Youyan 10.[Method] The net increment changes of individual plant fresh weight and dry matter weight of Youyan 9 and Youyan 10 with different nitrogen application treatments were studied.[Result]The differences among average fresh weight increments of individual plant and average dry matter weight increment of individual plant with different treatments reached 0.01 extremely significant level. Fresh weight increment and dry matter weight net increment of individual plant declined gradually with the increase of nitrogen application. In growth course,fresh weight net increment of individual plant increased firstly then decreased and the maximum was in beginning flowering stage,besides that dry matter net increment increased gradually and the maximum was in mature period.The correlations among fresh net increment,dry matter weight net increment and yield net increment were positive or extremely positive.[Conclusion]Under experimental condition,when nitrogen application was 225 kg/hm2,hybrid rape Yanyou 9 and Yanyou 10 with low erucic,low glucosinolate could obtain high yield.  相似文献   

3.
[Objective]The aim of the research was to provide reference for reasonable application of nitrogen fertilizer for high yield cultivation of hybrid rape cultivar Youyan 9 and Youyan 10.[Method] The net increment changes of individual plant fresh weight and dry matter weight of Youyan 9 and Youyan 10 with different nitrogen application treatments were studied.[Result]The differences among average fresh weight increments of individual plant and average dry matter weight increment of individual plant with different treatments reached 0.01 extremely significant level. Fresh weight increment and dry matter weight net increment of individual plant declined gradually with the increase of nitrogen application. In growth course,fresh weight net increment of individual plant increased firstly then decreased and the maximum was in beginning flowering stage,besides that dry matter net increment increased gradually and the maximum was in mature period.The correlations among fresh net increment,dry matter weight net increment and yield net increment were positive or extremely positive.[Conclusion]Under experimental condition,when nitrogen application was 225 kg/hm2,hybrid rape Yanyou 9 and Yanyou 10 with low erucic,low glucosinolate could obtain high yield.  相似文献   

4.
The effect of arbuscular mycorrhiza fungi （AMF） on plant growth and nutrition utilization in upland rice and mungbean intercropping system was studied. A pot experiment was conducted in the greenhouse and AMF colonization rates of rice and mungbean roots, plant nutrient contents, the ability of nitrogen fixation, and nutrient contents changed in the soil were analyzed. The results were obtained as follows： the rates of AMF colonization of rice and mungbean roots were reached to 14.47 and 92.2% in intercopping system, and increased by 4.11 and 11.95% compared with that of in monocropping; the nirtrogen contents of mungbean and rice were increased by 83.72 and 64.83% in shoots, and 53.76 and 41.29% in roots, respectively, while the contents of iron in shoot and root of mungbean were increased by 223.08 and 60.19%, respectively. In the intercropping system with inoculation of AMF, the biomass of mungbean increased by 288.8%. However, the biomass of rice was not significantly changed among all treatments with or without inoculation of AMF recorded. The number and dry weight of nodules were significantly increased either when mungbean was intercropped with rice or inoculated with AMF. When compared with that of monocropping without AMF inoculation, the contents of nitrogen, phosphorus and iron in nodules of intercropping mungbean with inoculation increased by 80.14, 69.54 and 39.62%, respectively. Additionally, intercropping with AMF inoculation significantly increased soil nitrogen content, but reduced soil phosphorus content. We concluded that upland rice-mungbean intercropping system and inoculation with AMF improved the nutrient uptake, the ability of nitrogen fixation and the growth of mungbean.  相似文献   

5.
With the rise of organic agriculture, researches on the production of slow-release organic fertilizer from natural organic materials have attracted much attention. Plant protein and peptides have potential applications in agricultural production. The effects of bioactive peptides derived from plant protein on rice seed germination and seedling growth and development were systematically studied using bioassays and greenhouse growth experiments. The feasibility of phytoprotein peptide application in the rice seedling stage was discussed. The results showed that the phytoprotein peptides had no adverse effects on rice, and the application when applied to rice seedlings, phytoprotein peptides within a certain concentration range produced obvious promotion effects on the growth and development of rice seedlings, which were more pronounced in the underground part of the plants. Phytoprotein peptides increased root length and dry matter accumulation and improved the robustness of rice seedlings. A 40 g·mol~(-1)·L~(-1) dose of phytoprotein peptides increased root length, plant fresh weight, plant dry weight, root fresh weight and root dry weight by 59.24%, 20.14%, 26.32%, 51.57% and 81.70%, respectively compared to the control. In addition, the phytoprotein peptides significantly increased the chlorophyll content, root activity and nitrate reductase activity of rice seedlings, as well as superoxide dismutase, peroxidase, catalase and β-1, 3-glucanase activity in rice leaves, which could improve stress resistance. Plant peptides were simple to produce and costeffective. Reasonable development and excavation of plant protein and protein hydrolysate peptide in China's agricultural application had a good practical basis and value significance.  相似文献   

6.
Effects of Plant Density on Forage Nutritive Value of Whole Plant Corn   总被引：2，自引：0，他引：2  
In the field experiment, the effects of plant densities (75 000, 112 500 and 150 000 plantsha^-1) on forage nutritive value of whole plant corn (WPC) were studied from 1999 to 2001.The results demonstrated that with the increasing of plant density, the forage matteryield per plant corn decreased significantly, while the fresh matter and dry matter perhectare corn increased significantly, and a higher grains yield was gotten at higherplant densities. Forage nutritive quality of whole plant corn was changed as plantdensity increased, the crude protein (CP), ether extract (EE), crude fiber (CF),nitrogen free extract (NFE) and general energy (GE) yields increased obviously. Increas-ing plant density reasonably with the application of plant growth regulators couldimprove plant properties, harvest more forage matter, and enhance forage nutritive valueof WPC.  相似文献   

7.
Convolvulus arvensis is a toxic allelopathic weed that suppresses germination and growth of crops.The prime object of present study was to investigate effect of Convolvulus arvensis water extract on germination and performance of okra with different seed sizes.The seeds of okra variety pusa green were separated into three different sizes,viz large size(4.00-5.00 mm),medium size(3.00-3.50 mm)and small size(2.00-3.50 mm),and then soaked in allelopathic plant bindweed water extract and kept in patrisdishes for germination into the germinator at 15℃.The experiment was laid out using Complete Randomized Design(CRD)with three replications.The results showed that after sowing of 12 days the highest germination was observed in non-treated seeds as compared to seeds treated in Convolvulus arvensis water extract for 1 h,further non-treated large seeds produced maximum plants as compared to treated small seeds after sowing of 24 days.Meanwhile,root length,shoot length,root fresh and dry weight,shoot fresh and dry weight were recorded higher in non-treated large seeds as compared to small seeds soaked for 1 h in Convolvulus arvensis allelopthic water extract.It could be found that Convolvulus arvensis affected germination,seed growth and overall performance of okra,further presence Convolvulus arvensis in crops could cause negative impact on germination and integrity of okra crops.  相似文献   

8.
By using single rice cultivation as a control, the effect of rice-fish culture on growth dynamic, plant type and yield formation of rice was studied. The results showed as follows： rice-fish culture improved the physical-chemical properties of arable layer soil of paddy field, extended growth period of rice, increased dry matter and LAI of different growth stages, improved three top leaves area, deterred the degeneration of leaves function, increased the diameter of stem, promoted the growth of roots and the formation of roots in the extended stem. At the same time, rice-fish culture extended the length of basal internodes, increased the number of internodes, uplifted the gravity of plant, and depressed the root vigor. For the grain yield and yield structure office, rice-fish culture decreased ear/tillering ratio, spikelet/panicle and seed set percentage, increased grain weight. If variety choice and cultivation technology were controlled appropriately, rice-fish culture could increase the effective panicles and improve grain yield of rice.  相似文献   

9.
Increasing salinity of the groundwater is one of major challenges faced by agricultural sector in West Bank/Palestine. This study was carried out in the Lower Jordan Valley （LJV） under greenhouse field condition, where an area of 0.12 ha was irrigated with 3.5 dS/m magnetic treated water during the growing season 2012/2013. The results of this pilot project show that there are significant increases in the yield of red and yellow bell pepper of about 20% and 18% on fresh weight basis, respectively. Water use efficiency increased by 15% and an increase in shelf time of 7 d were also recorded. The chlorophyll content raised significantly in the leaves of treated plants compared to the controlled one by 2.5 mg/g. Bell pepper irrigated with magnetic water produces 37% more four champers than that of the controlled one. On the other hand, there were no clear significant effects on the height of the plant, number of fruits, distance between nods, size of fruits, number and thickness of walls and sugar contents. Applying visible/near infrared （VIS/N｜R） spectroscopy test shows that it is possible to distinguish between treated and controlled bell pepper fruits. Multivariate data analysis （MVDA） method was used to test the classification of chemical elements in the fruit and it was found that treated and controlled fruit samples are divided into two groups according to their water treatment. An increase in all nutrient concentrations was found in fruits irrigated with magnetic treated water compared with the controlled one. Further testing is needed especially by involving other variables such as decreasing the volume of irrigated water and fertilizers.  相似文献   

10.
Variation laws of anthocyanin content in root during the development and among the varieties, and their relationships with major economic traits in purple-fleshed sweetpotato [Ipomoea batatas （L.） Lam] were studied in the present article. The dynamics of 20 economic traits in 13 purple-fleshed sweetpotato varieties at 20, 40, 60, 80, 100, 120, and 140 d after their transplanting were investigated, and these traits included anthocyanin content in root, length of the longest vine, number of base branches, root number, dry matter contents in stem, foliage and root, fresh/dry weight of root, fresh/dry weight of stem, flesh/dry weight of foliage, flesh/dry weight of stem and foliage, flesh/dry weight of whole plant, and rations of photosynthate to root, stem, and foliage. The correlations between the variations of anthocyanin content and the other 19 economic traits among varieties and during the whole developing stages, and the correlations of daily increase of anthocyanin content with other l0 kinds of yields were analyzed. The results showed that： （1） During the whole development, the anthocyanin content had three variation types, i.e. a slow-increase type, a fluctuating-change type, and a deviousrising type, and had different responses to the growth of length of the longest vine, number of base branches, flesh/dry yield of root, and photosynthate allotments. （2） The anthocyanin contents among 13 varieties began to have significant difference after 20 d, and showed completed differentiation during 40-100 d, which had significantly negative correlationships with the number of base branches, fresh/dry yield of root, photosynthate allotment ratio to root, and had significant positive correlationships with dry matter content of root, length of the longest vine, fresh/dry yield of stem, dry yield of whole plant and photosynthate allotment ratio to foliage. （3） Because of the significantly negative correlation between daily increase of anthocyanin content and dry matter weight of root, the anthocyanin a  相似文献   

11.
Double-seed sowing(two seeds per hole) is the dominant pattern of peanut sowing in China, but within-hole plant competition usually limits their growth and yield formation. Besides, the traditional double-seed sowing method does not facilitate mechanization during sowing. The objective of this study was to determine if single-seed sowing at a proper seeding rate yielded better than traditional double-seed sowing pattern and the differences of physiological metabolism of roots. A field experiment was conducted in two consecutive years to compare pod yields of single-seed sowing at 180 000(S180), 225 000(S225), and 270 000 seeds ha~(–1)(S270) with that of double-seed sowing at 270 000 seeds ha~(–1)(D270) using a completely randomized block design with four replications. And the root bleeding sap rate, nutrient content, and the main hormone contents in root bleeding sap were also comparatively investigated. Although the pod yields of single-seed sowing at the three densities were higher than that of traditional double-seed sowing(D270), S225 yielded better than the other two single-seed sowing treatments(S180 and S270). The increased pod yield in single-seed sowing at 225 000 seeds ha~(–1) was mainly due to the higher pod dry weight per plant and harvest index. The improved pod dry weight and shoot growth had closely relationship with the enhanced root physiological traits such as the increased root bleeding sap rate, content of free amino acids, soluble sugars, K~+, Mg~(2+), Zn~(2+), and Ca~(2+) of the individual plant root. The improved activity of root reductive, nitrate reductase(NR) and ATPase and higher zeatin and zeatin riboside(Z+ZR) content of root bleeding sap were alsocrucial to the pod and shoot growth of peanut. Single-seed sowing at a moderate seeding rate(S225) is a potential practice to increase pod yield and to save seed cost.  相似文献   

12.
A systematic study was conducted to determine the effects of water stress on the activities of protective enzymes and lipid peroxidation in maize. The results showed that, under water stress, the activities of superoxide dismutase （SOD）, catalase （CAT）, and peroxidase （POD） in leaves and roots increased sharply at prophase and metaphase growth stages, such as, male tetrad stage, but then declined towards the physiological maturity. The protective enzyme activities in roots were lower than those in leaves. The content of malondialdehyde （MDA） increased according to the severity of water stress. The content of MDA in roots was lower than that in leaves. The activities of protective enzymes and lipid peroxidation in roots were positively related to that in leaves with most of the correlation coefficients being significant. The content of soluble proteins in roots and leaves decreased with increasing drought stress. The ear characteristics deteriorated and the economic yields of maize decreased significantly under water stress. The main factors that caused reduction of yields were the decrease in the number of ear kernels and 100-kernel weight.  相似文献   

13.
DCPTA （2-diethylaminoethyl-3, 4-dichlorophenylether） is a new plant regulator which can be used to regulate growth and development for crops. Experiments on maize seedlings were conducted in the growth chamber to study the effects of foliar applied DCPTA. The plant pots were placed in a completely randomized design with three replicates. The maize seedlings were treated with 0 mg·L-1 （control）, 20 mg·L-1 and 40 mg·L-1 DCPTA solution. The effects of DCPTA on the photosynthetic characteristics （photosynthesis, stomata conductance, intercellular CO2, and transpiration rate）, related physiological characteristics （contents of soluble sugar and starch）, chlorophyll fluorescence parameters （Fo, Fro, Fv/Fm, Fv/Fo, qP, and qN） and the weight of dry matter in maize seedling were studied. The results showed that DCPTA enhanced photosynthesis of maize seedling. In general, photosynthetic rate in leaves was significantly promoted through spraying DCPTA solution, and 40 rag＂ L~ DCPTA was found to be the best concentration for maize. The relationship between stomata conductance and transpiration rate in maize leaves could be described as linear. With regard to the chlorophyll fluorescence parameters, our fmdings showed that 40 mg·L-1 DCPTA in maize seedling caused an increase in Fm, Fv/Fm, Fm/Fo, qP and a decrease in Fo and qN at some time points checked. It is suggested that DCPTA increased photosynthetic rate by raising both the content of chlorophyll and activities of PSII and the contents of sugar and starch. Compared with the control, the treated maize seedling caused an increase in plant height, root length, shoot dry mass, root dry mass, or the total （root plus shoot） dry mass.  相似文献   

14.
Soybean Dongnong 47 was subjected to the experiments of increasing UV-B radiation and water stress on soybean yield components in different growth periods. The results showed that 100-seed weight greatly increased during the early stage of pod filling in the treatment of weak UV-B radiation, seed number per plant as well as seed weight per plant and Dongnong47 yield also increased, while the yield and yield components of Dongnong47 during the blossom to mature period were negatively affected in the treatment of intensive UV-B radiation. 100-seed weight of Dongnong47 all increased in the double factor treatments of UV-B radiation and water stress, with the drought intensified, seed number per plant, seed weight per plant and yield of Dongnong47 decreased, the change of 100-seed weight were various and the antagonistic action of UV-B radiation and water stress were related with their intensity.  相似文献   

15.
Plough pans(PPs),common in the black-soil region of northeastern China,have significant effects on the root systems of crops. We conducted a field experiment to study the distribution of soybean roots under the influence of PPs. The soybean roots showed compensatory growth above the PP,with higher root length and weight in soil with a PP compared to those without a PP. Roots were heavier and longer in the 15–75 cm soil layer without a PP than with a PP. Soil porosity was lower in the PP and the soil below the PP,which likely decreased the oxygen content of the soil and induced more growth of roots above the PP. The PP is also likely to decrease infiltration of rain-water and hinder the migration of nitrate downward,which in turn increased the density and length of soybean root hairs,which,hence,promoted growth.  相似文献   

16.
The relation between soil water content and the growth of cotton root was studied for the scheme of field water and cotton yield under mulched drip irrigation. Based on the field experiments, three treatments of soil water content were conducted with 90%, 75%θf, and 60%θf （θfis field water capacity）. Cotton roots and root-shoot ratio were studied with digging method, and the soil moisture was observed with TDR （time domain reflector）, and cotton yield was measured. The results indicated that the growth of cotton root accorded with Logistic growth curve in the three treatments, the cotton root grew quickly and its weight was very high under 75%θf because of the suitable soil water condition, while grew slowly and its weight was lower under 90%θf due to water moisture beyond the suitable condition, and the root weight was in between under 60%θf For the three water treatments, the cotton root weight decreased with soil depth, and decreased more significantly in deeper soil layer with the soil moisture increasing. And the ratio of cotton root weight in 0-30 cm soil layer to the total root weight was the highest under 75%θf. The cotton root system was distributed mainly in the soil of narrow row and wide row mulched with plastic film, and little in the soil outside plastic film. The weight of cotton root was the highest in the soil of narrow row or wide row mulched with plastic film under 75%θf. Root-shoot ratio decreased with the soil moisture increasing. The soil water content affected cotton yields, and cotton yield was the highest under 75%θf. The higher soil moisture level is unfavorable to the growth of cotton root system and yield of cotton under mulched drip irrigation.  相似文献   

17.
Melatonin is a naturally occurring compound in plants. Here, we tested the effect of exogenous melatonin on rapeseed(Brassica napus L.) grown under salt stress. Application of 30 μmol L~(–1) melatonin alleviated salt-induced growth inhibition, and the shoot fresh weight, the shoot dry weight, the root fresh weight, and the root dry weight of seedlings treated with exogenous melatonin increased by 128.2, 142.9, 122.2, and 124.2%, respectively, compared to those under salt stress. In addition, several physiological parameters were evaluated. The activities of antioxidant enzymes including peroxidase(POD), catalase(CAT) and ascorbate peroxidase(APX) were enhanced by 16.5, 19.3, and 14.2% compared to their activities in plants without exogenous melatonin application under salt stress, while the H_2O_2 content was decreased by 11.2% by exogenous melatonin. Furthermore, melatonin treatment promoted solute accumulation by increasing the contents of proline(26.8%), soluble sugars(15.1%) and proteins(58.8%). The results also suggested that higher concentrations(50 μmol L~(–1)) of melatonin could attenuate or even prevent the beneficial effects on seedling development. In conclusion, application of a low concentration of exogenous melatonin to rapeseed plants under salt stress can improve the H_2O_2-scavenging capacity by enhancing the activities of antioxidant enzymes such as POD, CAT and APX, and can also alleviate osmotic stress by promoting the accumulation of osmoregulatory substances such as soluble proteins, proline, and water soluble glucan. Ultimately, exogenous melatonin facilitates root development and improves the biomass of rapeseed seedlings grown under salt stress, thereby effectively alleviating the damage of salt stress in rapeseed seedlings.  相似文献   

18.
In order to study the microwave-assisted foam-mat drying properties of corn soaking water and optimize process parameters, a quadratic regression orthogonal rotary method was used to analyze the influence of microwave power, material weight, material thickness and drying time on moisture content (dry basis), color value and protein content. Results showed that the primary and secondary sequence of parameters with regard to moisture content (d. b.) was drying time, microwave power, material weight and material thickness; the primary and secondary sequence of parameters with regard to color value was material weight, drying time, microwave power and material thickness; the primary and secondary sequence of parameters with regard to protein content was drying time, material weight, microwave power and material thickness. Optimum conditions were obtained as microwave power of 560 W, material weight of 46.88 g, material thickness of 6.20 mm and drying time of 8.01 min. The results might provide the theoretical basis and technical support for the microwave-assisted foam-mat drying of corn soaking water to produce yeast protein power.  相似文献   

19.
Adequate regulation of mineral nutrients might be effective to ameliorate the deleterious effects of salts and help to sustain crop productivity, particularly in glycophytes, under salt stress. In this study, laboratory and greenhouse experiments were carried out at Agricultural and Natural Resources Research Centre in East Azerbaijan, Iran, to investigate the interactive effects of silicon and potassium nitrate in alleviating NaCl induced injuries in wheat（Triticum aestivum L.）. In the laboratory experiment, three winter wheat cultivars Pishgam, Afagh and Alvand were grown on sterile filter paper moistened with 20, 40, 60, 80, and 100 mmol L-1 NaCl solution. Results revealed that wheat cultivars were significantly different in their growth response to different concentrations of NaCl and Pishgam was found to be the most tolerant to NaCl stress, and used in the second part of study. In the greenhouse experiment, Pishgam was grown in a hydroponic system subjected to different NaCl levels（20, 60 and 100 mmol L-1） and treated by silicon（0, 2 and 4 mmol L-1, final concentration in nutrient solution using K2SiO3） and potassium nitrate（0, 0.5, 1, and 2 mmol L-1, foliar application）. The experimental design was factorial based on a completely randomized design with three replications. It was found that NaCl stress significantly increased proline accumulation and sodium content in the plant tissues while decreased potassium uptake and accumulation by plants. Moreover, plant weight, 100-seed weight, relative water content, chlorophyll content, and photosynthesis were also significantly affected by varying levels of NaCl. However, exogenous application of silicon and potassium nitrate reduced sodium uptake, increased potassium and consequently improved plant weight, 100-seed weight, seed yield, ear length, and photosynthesis rate. This study suggested that utilization of the salt-tolerant cultivar（Pishgam） combined with proper foliar application of potassium nitrate（2 mmol L-1） and silicon（4 mmol  相似文献   

20.
过量Mg~(2+)对农作物种子萌发特性的影响(英文)   总被引：7，自引：0，他引：7  
[Objective] The research aimed to reveal the effects of excessive Mg2+ on the germination characteristics of maize and soybean. [Method] Eleven concentration gradients of Mg2+ including 0,40,80,120,160,200,240,280,320,360 and 400 mmol/L were set up to study the effects of different treatments on such indices as the germination potential,germination rate,fresh weight,dry weight,root length,plant height and stem diameter of maize and soybean. [Result] With the increasing of Mg2+ concentration,the germination of maize delayed and the germination rate of soybean obviously decreased,reaching the significant difference at 0.05 level. When Mg2+ concentration increased,the fresh weight and dry weight of maize and soybean decreased,but maize and soybean showed some adaptability. The growth of radicles and seedlings in maize and soybean were obviously inhibited by Mg2+,and atrophy and dysplasia phenomena appeared. [Conclusion] Excessive Mg2+ stress has different effects on the germination potential and germination rate of different crops and has obvious poisoning effects on the root and stem growth of crops.  相似文献   

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