首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Abstract

Water containing 6 mM sodium bicarbonate was used for soaking mung bean seeds for 9 hrs arid for frequent spraying of sprouts for the rest of 5 days. A concentration series of calcium as nitrate showed that 0.25 meq/1 calcium in this solution was sufficient for maximum yield in 5 days; additional calcium up to 6 meq/1 did not increase yield. The requirement for calcium was independent of the effect of calcium on partially preventing sodium uptake. Calcium in the dry seed did not replace the requirement for external calcium. The minimum calcium requirement was associated with maintaining or increasing the 9‐hr. calcium content for the rest of the 5‐day growing period.  相似文献   

2.
The response of four cultivars of pepper (Capsicum annuum L.), Yolo Wonder, HDA 103, HDA 174, and SC 81 to sodium chloride (NaCl) salinity was studied in hydroponic culture by comparing three different NaCl concentrations: 0 mM, 50 mM, and 100 mM. For all cultivars, growth was reduced when NaCl concentration in the growth medium increased. However, cultivar behavior as a function of the NaCl concentration was not homogenous. The HDA 174 displayed the best growth when NaCl concentration was high, while Yolo Wonder was the most sensitive to salinity. The SC 81 showed intermediate behavior since its growth was low at all treatment levels, but it reacted only slightly to increasing salinity. The analytical results showed that growth was very closely linked to the zinc (Zn) content of the blade: the best growth was observed when the percentage of Zn in the blade was low, whereas high Zn content was linked to sharp reduction in growth. The most tolerant cultivar, HDA 174, showed an original response: the sodium (Na) was strongly accumulated in the leaf blade, whereas the other cultivars tended to avoid Na accumulation. This corresponded to an adaptation observed for halophyte plants.  相似文献   

3.
In the previous work concerning the effect of potassium nutrition on glycolysis in sweet potato roots (1), monoiodoacetic acid (MIA) and sodium fluoride (NaF) inhibited more strongly respiration in younger roots and root tip parts, and yet a potassium deficiency enhanced its inhibition. The inhibition of MIA, which inhibits triose phosphate dehydrogenase (2), may indicate the importance of the EMP pathway and the Krebs cycle (3,4). The inhibition of NaF, which in higher concentrations inhibits enolase (2), may suggest the importance of the metabolism following phosphoglycerate → phosphoenolpyruvate or the Krebs cycle (3,4). It is of interest, therefore, to elucidate the role of the Krebs cycle in respiration in sweet potato roots, and what significance potassium nutrition has in the Krebs cycle operation. This paper deals with experiments bearing on respiration in roots of sweet potato plants grown at varying degrees of potassium application, especially in the presence of various inhibitors and / or substrates.  相似文献   

4.
The present study is an attempt to evaluate the protective effects of environmental chlorides (as NaCI and CaCl2) on nitrite-induced methemoglobinemia to the fresh water telcost Clarias lazera. Two aspects were investigated, including the determination of the minimum ratio of chloride to nitrite ion required to inhibit nitrite-induced methemoglobinemia, and the ability of chloride to reverse methemoglobin formation in fish previously exposed to nitrite.  相似文献   

5.
Sodium arsenite (NaAsO2) was applied to two Vitis vinifera varieties, Aledo and Italia, for three years at a concentration of 1.25 kg NaAsO2100 L‐1 applied by spraying or by direct application with a paint brush. Accumulation of arsenic (As) in leaves and fruits during these three years was not detected. Spraying resulted in the highest levels of As in the leaf with the concentration decreasing as the vegetative cycle advanced. The amount of As that accumulated in the plant was related to the proximity of the As application to bud break. The As levels detected in the eatable part (table grape) never reached concentrations that would be considered harmful to human beings.  相似文献   

6.
A glasshouse experiment was carried out in order to study the effect of ammonium supply [0 and 1.5 mmol L‐1 in the nutrient solution, whereas total nitrogen (N) concentration was 9.5 mmol L‐1] on nutrient uptake, leaves, and xylem sap composition and growth of bean plants in sand culture. Ammonium supply caused higher nitrogen, phosphorus (P), potassium (K), and calcium (Ca) uptake. However, K, Ca, and magnesium (Mg) concentrations in the plants (in xylem sap and leaves) were lower when ammonium was supplied. Plants vegetative growth was higher with ammonium supply than without it, specially after four weeks of cultivation.  相似文献   

7.
The addition of various sodium chloride (NaCl) doses (2–150 meq/L) to a balanced standard nutrient solution brought about an increase in the sodium (Na) content of all the vegetative organs of grapevine. The Na ‐ potassium (K) antagonism was shown by the decrease in K content, even at low NaCl doses. The calcium (Ca) and magnesium (Mg) contents of the various plant organs were also decreased as the NaCl content of the nutrient solution was increased. The cationic sums for the various plant organs remained constant, with the exception of the highest NaCl dose which was lethal after two months.  相似文献   

8.
在田间试验条件下,调查了品种2号、中绿5号和冀绿9号3个绿豆品种接种根瘤菌菌剂对植株及产量等性状的影响.研究发现,接种根瘤菌可显著促进品种2号和冀绿9号两个绿豆品种的生长,根瘤数量明显增多,产量分别增加41%和29%;中绿5号接种根瘤菌后,产量不增反降,但总根瘤数要明显高于对照,且主根瘤数也高于其他两个品种.从而建议根瘤菌的应用应与品种相匹配.  相似文献   

9.
Purpose

Fast and real-time prediction of leaf nutrient concentrations can facilitate decision-making for fertilisation regimes on farms and address issues raised with over-fertilisation. Cacao (Theobroma cacao L.) is an important cash crop and requires nutrient supply to maintain yield. This project aimed to use chemometric analysis and wavelength selection to improve the accuracy of foliar nutrient prediction.

Materials and methods

We used a visible-near infrared (400–1000 nm) hyperspectral imaging (HSI) system to predict foliar calcium (Ca), potassium (K), phosphorus (P) and nitrogen (N) of cacao trees. Images were captured from 95 leaf samples. Partial least square regression (PLSR) models were developed to predict leaf nutrient concentrations and wavelength selection was undertaken.

Results and discussion

Using all wavelengths, Ca (R2CV?=?0.76, RMSECV?=?0.28), K (R2CV?=?0.35, RMSECV?=?0.46), P (R2CV?=?0.75, RMSECV?=?0.019) and N (R2CV?=?0.73, RMSECV?=?0.17) were predicted. Wavelength selection increased the prediction accuracy of Ca (R2CV?=?0.79, RMSECV?=?0.27) and N (R2CV?=?0.74, RMSECV?=?0.16), while did not affect prediction accuracy of foliar K (R2CV?=?0.35, RMSECV?=?0.46) and P (R2CV?=?0.75, RMSECV?=?0.019).

Conclusions

Visible-near infrared HSI has a good potential to predict Ca, P and N concentrations in cacao leaf samples, but K concentrations could not be predicted reliably. Wavelength selection increased the prediction accuracy of foliar Ca and N leading to a reduced number of wavelengths involved in developed models.

  相似文献   

10.
The response of tomato (Lycopersicum esculentum Mill, cultivar Marmande) plants to different levels of arsenic (As) in nutrient solution was investigated—the processes of uptake, distribution and accumulation of As, and the effect of arsenite on yield and plant growth (plant height, diameter of stem, stem and root length, fresh and dry weight of root, stems, leaves, and fruit). The experiment was performed at three levels of As: 2, 5 and 10 mg/L [added as sodium arsenite (NaAsO2)] in a nutrient solution, together with the corresponding control plants. Arsenic uptake depended on the As concentration in solution and As content in the roots increased as the time of treatment increased. The most important finding was the high toxicity of arsenite to roots. The concentration in stems, leaves, and fruit was correlated with the As level in the nutrient solution. Although the As level of 10 mg/L damaged the root membranes, resulting in a significant decrease in the upward transport of As. Arsenic exposure resulted in a drastic decrease in plant growth parameters (e.g., maximum decrease of 76.8% in leaf fresh weight) and in tomato fruit yield (maximum reduction of 79.6%). However, it is important to note that the As concentration in the fruits was not toxic or harmful for human consumption.  相似文献   

11.
Winter varieties of canola (Brassica napus L.) are susceptible to winterkill. Measurements of photosynthetic efficiency and survival of field-grown canola were used to evaluate the effect of chloride (Cl), potassium (K), and phosphorus (P) nutrition on winter field survival in northwestern USA. In a growth chamber experiment, effects of calcium chloride (CaCl2), potassium chloride (KCl), ammonium chloride (NH4Cl), or sodium chloride (NaCl) on the ability to tolerate subfreezing temperatures were evaluated. In the field, overwinter survival was higher, and greater photosynthetic activity continued later into the autumn in plants with increased sap Cl concentrations. In the greenhouse experiment, significantly greater survival occurred in plants with higher sap Cl concentrations, but only in plants that had not been cold acclimated. These results suggested that a greater concentration of chloride ion in the sap of canola plants is related to an increased ability to tolerate subfreezing temperatures, but other processes resulting from cold acclimation may largely obscure this effect.  相似文献   

12.
不同供磷水平对饭豆体内铁有效性的影响   总被引:1,自引:0,他引:1  
采用溶液培养试验研究了低铁条件下(1 μmol/L FeEDTA)不同供磷水平P 3、30和300 μmol/L对饭豆叶绿素含量、生物量、铁含量以及质外体铁的影响。结果表明,饭豆叶片叶绿素含量及根系干重均随磷处理浓度的增加而显著降低; 低磷处理的植株地上部的铁含量明显高于中磷和高磷处理。随着供磷水平的增加,地上部和根系总铁量的比值呈降低趋势,说明铁由根系向地上部的转运显著减少,从而加剧了植株缺铁症状。进一步分析发现,低磷处理的根系质外体铁含量显著低于中磷和高磷处理。说明在铁吸收过程中,供磷水平增加促使铁在根系质外体空间中的固定,不利于根系中的铁转运至地上部,这可能是磷是对铁产生拮抗作用造成植物铁营养不利的原因之一。  相似文献   

13.
The effects of different levels of arsenic (As) and salinity on bean plant (Phaseolus vulgaris L., cv. Buenos Aires) nutrition were investigated. We studied the processes of absorption and accumulation of chloride (Cl) and micronutrient elements: boron (B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn). The experiment was performed in soilless culture at two levels of As: 2 and 5 mg As L‐1 [added as sodium arsenite (NaAsO2)], and three saline levels [only sodium chloride (NaCl) was added]: 1, 2, and 4 dSm‐1. Sodium arsenite and NaCl significantly affected micronutrients allocation within the bean plant at levels used in this study. Arsenite depressed Mn and Cl concentrations in the root, whereas root B, Cu, and Zn levels were increased. Boron, Cu, Fe, and Cl concentrations were significantly higher in As‐stressed plants compared with controls. The addition of NaCl increased the Cl and Mn concentrations in roots and Cl, Fe, and Mn in leaves.  相似文献   

14.
A study of winged beans ‐Psophocarpus tetragonolobus (L.)‐ fertilization was performed on laboratory environment. Three major plant nutrients, N, P and K were used in increasing amounts to determine the effectiveness of each of above nutrient in the plant development. The plants were grown for two months under controlled light, humidity and temperature control.

Under those experimental conditions and data obtained there was no positive effect of N treatment, rather negative, preventing nodule formation and effectiveness of other nutrients. The most significant nutrient, according to the experiments, is P, showing the highest increase in green and dry mass. The K is most effective at low me dium ratios and is suggested only on K poor soils.

The best recommendation, according to this experiments for winged bean fertilization, is 0–2–1 fertilizer ratio.  相似文献   

15.
Nitrogen nutrition has great influences not only on the growth, but also on leaf quality of tobacco. There have been many reports on the nitrogen nutrition of tobacco, in which various nitrogen constituents such as amino acids and related compounds have been analyzed. But definite conclusions were often hard to be drawn out, since sometimes the work was limited by the failure of finding suitable chemical techniques. The recent development of paper chromatographic methods, however, has made possible to detect the individual amino acids, and has provided a new approach to the study of nitrogen nutrition of tobacco. Using the paper chromatographic techniques, the effects of nitrogen form, the effect of sulfur nutrition and excess of chlorine on free amino acid composition of tobacco leaf have been reported by the authors (1). The next step of the work presented here was undertaken for the quantitative study of the effect of nitrogen nutrition on free amino acid content of tobacco cultured for commercial purpose employing the amino acids estimation method developed by MOORE and STEIN (2) (3).  相似文献   

16.
Laboratory incubations were conducted to study the effect of sodium chloride (NaCl) on denitrification and respiratory gases (CO2, O2) from soil treated with ammonium or nitrate and incubated at 20 % moisture. The same samples were assayed for denitrifying enzyme activity (DEA) after incubation at 40 % moisture with glucose and NO3. Under aerobic conditions (20 % water content), a flush of activity was observed at 6 hours after start of incubation and subsided to negligible levels at 12 hours. Sodium chloride significantly depressed N2O and CO2 emissions and O2 consumption. Significantly more loss of N2O occurred from NH4+‐ than NO3‐treated soil at all NaCl levels and was attributed to higher microbial activity. A highly significant positive correlation was obtained between N2O emission and respiratory gases. The respiratory quotient (CO2 evolved/O2) was higher for NH4+‐treated soil and decreased with the amount of NaCl. At 40 % moisture, N2O emissions were higher than at 20 % and peaked at 37 hours followed by a sharp decrease. Short‐term incubations of soil with NH4+ or NO3 did not have an effect on denitrifying enzyme activity (DEA) while NaCl had a positive effect, particularly in previously NO3‐treated soil.  相似文献   

17.
The effect of mercuric chloride (HgCl2) on electron transport system (ETS) activity in sediment was studied using the reduction of 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride (INT) to water insoluble iodonitrotetrazolium formazan (INT-formazan) by respiring microorganisms and sediment enzymes. The effect of HgCl2 on ETS activity was more pronounced in aerobically incubated sediment than in anaerobically incubated sediment. The EC50 value for the inhibition of ETS activity in aerobically incubated sediment at 10 and 20 °C was 40.9 ± 16.2 and 48.8 ± 4.1 μg g?1 HgCl2, respectively. The EC50 value for anaerobically incubated sediment in the presence of HgCl, at 4, 10, and 20 °C was 153.0 ± 8.1, 173.1 ± 8.2, and 199.1 ± 15.2 μg g?1 HgCl2, respectively.  相似文献   

18.
Abstract

The efficacy of using various levels of potassium (K) (4, 8, and 16 mM) under saline conditions to alleviate the detrimental effects of salt‐stress were studied using five tomato (Lycopersicon esculentum Mill) cultivars, ‘Strain 19’, ‘Pearson’, ‘Montecarlo’, ‘Maruthuam’, and ‘Pusa Rub’. Results of the study revealed that 50 mM sodium chloride (NaCl) in a Hoagland nutrient solution significantly reduced stem height, fruit weight, and whole plant dry weights, but increased number of fruits/plant and improved fruit quality by increasing total soluble solids. It did not significantly affect leaf count, percent fruit set, or dry weight. The addition of 4, 8 and 16 mM potassium nitrate (KNO3) to the nutrient solution containing 50 mM NaCl resulted in sodium/potassium (Na/K) ratios of 12.5, 6.3, and 3.1, respectively. The Na/K ratios of 12.5 and 6.3 produced significant improvement in stem height, percent fruit set, number of fruits/plant, fruit weight, and whole plant dry weight. The Na/K ratio of 3.1 was found to be detrimental as it resulted in sharp reduction of plant dry weight compared to the control. Percent total soluble solids was not significantly affected by the addition of any level of K to the saline nutrient solution. The performance of the tomatoplant grown under saline conditions supplemented with K in the nutrient solution indicated a higher response at the lowest K concentration used in this study.  相似文献   

19.
Alluvial soils with illite and vermiculite clay minerals are highly potassium (K)‐fixing. Such soils have been reported to require a huge amount of K fertilization for optimum plant growth. For halophytic plants such as sugar beet, sodium (Na) can be an alternative to K under such conditions. This study was conducted to investigate the possible substitution of K by Na fertilization with reference to K‐fixing soils. Three soils, i.e., Kleinlinden (subsoil), Giessen (alluvial), and Trebur (alluvial), differing in K‐fixing capacities, were selected, and sugar beet plants were grown in Ahr pots with 15 kg soil pot–1. Three treatments (no K and Na, K equal to K‐fixing capacity of soil, and Na equivalent to regular K fertilization) were applied. In a second experiment, containers (90 cm × 40 cm × 40 cm) were used with 170 kg Kleinlinden soil each, and one sugar beet plant per container was grown. In both experiments, plants were grown till beet maturity, and beets were analyzed for sucrose concentration and other quality parameters such as α‐amino nitrogen to calculate white‐sugar yield with the New Brunswick formula. The results showed that growth and quality of sugar beet were not affected by Na application, and ultimately there was no decrease in white‐sugar yield. Moreover, the soils with more K‐fixing capacity were more suitable for K substitution by Na. It is concluded that Na can substitute K in sugar beet nutrition to a high degree and soils with high K‐fixing capacity have more potential for this substitution.  相似文献   

20.
Four nutrient solutions with different P‐levels (0.2; 0.5; 2.0 and 4.0 mmol P/l) were studied in order to optimize P nutrition of the tomato plant. A N/P ratio decrease in sap and the leaf was observed when P supply increased. Moreover, excessive and deficient P levels in the nutrient solution resulted in a flavonol glycosides decrease in leaves, specially at flowering. Chlorophyll a/chlorophyll b ratios and chlorophyll a percentages, as compared with the total, were lower in the P‐0.2 and P‐0.5 treatments than in the P‐2.0 treatment.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号