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1.
Abstract

It is well known that stem nodules are formed on the aerial parts of Aeschynomene spp. and Sesbania rostrata grown in the field (Yatazawa and Yoshida 1979; Dreyfus and Dommergues 1981; Yoshida et al. 1985). We have reported that stem nodules were successfully formed by inoculation of Rhizobium isolates derived from both stem and root nodules of A. indica (Yoshida et al. 1985; Sasakawa et al. 1986). The specific activity of nitrogen fixation in stem nodules is comparable to that of root nodules (Sasakawa et al. 1986; Sasakawa 1990). A red pigment, which suggests the presence of leghemoglobin, was detected in stem nodules as well as in root nodules (Yatazawa and Yoshida 1979; Yatazawa and Susilo 1980; Sasakawa et al. 1986).  相似文献   

2.
Glutathione which is an abundant reduced sulfur compound in plants is considered to play important roles in the transmission of the sulfur nutrient status between organs within the plant body and in the long-distance transport of reduced sulfur. We determined the concentrations of glutathione, γ-glutamylcysteine (γ-EC), sulfate in the rice phloem sap collected by the insect laser technique. Phloem sap was collected from the plants cultured in sulfur-deficient and control solutions. The concentration of glutathione in the rice phloem sap was higher than that of sulfate in both control and sulfur-deficient plants. Under sulfur-deficient condition, the concentration of glutathione in the phloem sap did not decrease, whereas the sulfate concentration decreased significantly. The pattern of changes in γ-EC concentration was similar to that of glutathione. These data indicate the presence of mechanisms for the maintenance of a constant glutathione concentration in the phloem sap in rice plants under sulfur deficiency, whereas the sulfate concentration was found to be relatively unstable.  相似文献   

3.
【目的】氮和钾是作物生长所必需的大量元素,在水稻生长发育、产量形成等过程中发挥着至关重要的作用。南方稻田缺钾以及氮钾肥不合理施用已成为限制水稻高产的重要影响因子。本研究在田间条件下,探讨了不同施氮量下缺钾对水稻生长发育与叶片生理特性的影响,进而阐明缺钾导致营养生长期水稻叶色暗绿的营养及生理机制。【方法】采用两因素完全随机设计田间试验,因素A为不同施氮水平,包括不施氮、低氮(N 90 kg/hm2)和正常施氮(N 180 kg/hm2);因素B为不同施钾水平,包括不施钾和正常施钾(K2O 120 kg/hm2)。测定水稻分蘖期和幼穗分化期地上部干物质,叶面积指数,叶片氮、钾、镁和叶绿素含量(叶色值),叶片含水率、叶片可溶性糖含量、比叶重以及叶片SPAD值。【结果】1)在不施氮条件下缺钾对水稻分蘖期和幼穗分化期干物质、叶面积指数均无显著影响,而在施氮条件下显著降低水稻分蘖期和幼穗分化期干物质、叶面积指数;随施氮量的增加,缺钾对干物质及叶面积指数的影响加剧,其中N180K0处理的降幅最为明显;氮钾交互作用对水稻各生育期的干物质和叶面积指数均有显著或极显著影响。2)在不施氮条件下缺钾对分蘖期和幼穗分化期叶片氮含量和叶绿素含量、叶片可溶性糖含量、比叶重以及叶片SPAD值均无显著影响,而在施氮条件下以上各指标显著增加,其中N90K0处理的叶片氮含量和叶绿素含量均可以达到N180K120处理水平;无论施氮与否,缺钾均显著降低分蘖期和幼穗分化期叶片钾含量,而显著增加叶片镁含量。3)回归分析结果表明,比叶重与叶片可溶性糖含量呈极显著正相关关系(P < 0.01)。【结论】水稻干物质、叶面积指数、叶片营养及生理状况、叶色表现等对缺钾的响应明显受到施氮量的影响。在施氮条件下缺钾造成叶片中可溶性糖大量积累,进而导致比叶重增加;结合田间试验观察及叶片营养及生理性状可知,水稻叶色(叶绿素含量)在不施氮条件下不受缺钾的影响;而在施氮条件下,缺钾造成水稻叶片单位质量及单位叶面积氮含量和叶绿素含量显著增加,这是田间条件下水稻叶色呈现暗绿的主要原因,从而也影响生育期植株氮素营养诊断。  相似文献   

4.
The N-terminal amino-acid sequence of a major rice phloem-sap protein, designated as RPP23, was determined. The complete amino-acid sequence of RPP23 was deduced from the corresponding rice EST- clone and contained an extra 46 amino acids at the N-terminus, that was apparently cleaved off to form mature RPP23 in sieve tubes. RPP23 shared a similarity to plant small heat-shock proteins (smHSPs), though the N-terminal region of RPP23 was distinct from that of known smHSPs. Immunocytological analyses using leaf sections showed that RPP23 was located only in the phloem regions of leaves, and was present in non-stressed plants. In mature leaves, stronger immunocytological signals were detected in sieve elements than in companion cells.  相似文献   

5.
Eight species of tropical foliage plants were screened to determine their response to Fe‐stress conditions. Plants were grown for 120 days in modified Hoagland's nutrient solution at pH 6.3 containing either 0, 0.22 or 5.52 mg/liter Fe (as Fe+3‐HEEDTA). Araucaria heterophylla and Dracaena marginata showed leaf chlorosis and decreased growth at 0 and 0.22 mg/liter Fe. Ficus benjamina and Nephrolepis exaltata ’Bostoniensis’ showed little or no chlorosis or growth differences at either 0 or 0.22 mg/liter Fe. Over a 3 week period, F. benjamina and N. exaltata ’Bostoniensis’ decreased nutrient solution pH approximately 1 to 1.5 units lower than either D. marginata or A. heterophylla at all Fe levels. Codiaeum variegatum var. pictum, Dieffenbachia maculata ’Camille’, Epipremnum aureum, and Philodendron scandens oxycardium were intermediate in growth, chlorosis and lowering of the nutrient solution pH. One explanation for the differential Fe response between these species may be their ability to lower pH of the rhizosphere.  相似文献   

6.
Effects of Al (0–100 μM) and Si (0–2,000 μM) supplied singly or in combination on root growth of different rice varieties were examined under hydroponic conditions. Al addition inhibited root elongation of rice plants, and the inhibition increased with increasing amount of Al in the culture solution. Among 22 indica varieties and among 8 japonica varieties tested, IAC3 and Nakateshinsenbon were relatively tolerant to AI, respectively, whereas IR45 and Norinl were relatively sensitive to AI, respectively. Si exerted a beneficial effect at all levels of Si treatment on indica varieties, whereas Si supply resulted in a slight increase in the root dry weight of japonica varieties only at the highest level (2,000 μM Silo The alleviation of Al inhibition of rice root growth by Si was observed in the combination of Al and Si treatments. Alleviation was more pronounced for all the Si treatments in indica varieties than in japonica varieties, and the alleviation was maximum with 2,000 μM Si in IR45. The alleviation effect by Si was more pronounced in the AI-sensitive varieties than in the AI-tolerant varieties. The application of Si resulted in an increase in the contents of Al and Si in plants, and there was no relationship between the Al content and Al inhibition in plants.  相似文献   

7.
Information on the effects of phosphorus (P) and sulfur (S) applications on crop response and soil-P status of two-row malt barley (Hordeum vulgare L.) under high-input conditions are limited in alkaline soils despite widespread fertilizer-P and -S use. A field study was conducted during the 2015 and 2016 growing seasons where the barley cultivars (ABI-Voyager and Moravian 69) were grown at five rates of P (0, 37, 73, 110, and 147?kg P ha?1) and three rates of S (0, 112, 224?kg S ha?1). ABI-Voyager had significantly greater biological yield (17,023?kg ha?1) and grain yield (7433?kg ha?1) but a lower (44%) harvest index (HI) than Moravian 69 (15,037?kg ha?1, 7168?kg ha?1 and 49%, respectively). Grain yield increased with rate of P-application until 37?kg P ha?1 where the maximum calculated yield was obtained at 98?kg P ha?1 by a quadratic model. Sulfur application had no significant effect on any of the measured crop or soil parameters. Olsen P increased linearly with greater fertilizer-P applications, indicating grain-P removal was not sufficient to reduce or retain STP concentrations at initial levels when P was applied. Crop-P uptake and soil-P response to fertilizer P applications are important, as remaining soil P is available for subsequent crop usage and may have potential negative environmental impacts. Thus, cultivar selection and appropriate fertilizer-P and S management will ensure optimal agronomic and economic returns while minimizing potentially negative environmental impacts for two-row malt barley produced in the western United States.  相似文献   

8.
硫硼营养对烟叶石油醚提取物合成的影响   总被引:3,自引:0,他引:3  
硫素和硼素营养对烟叶石油醚提取物的合成起着重要作用。通过田间试验研究硫素、硼素营养对与烟叶石油醚提取物合成有关的6-磷酸葡萄糖脱氢酶、异柠檬酸裂解酶、磷脂酸磷酸酯酶活性的影响及提高石油醚提取物含量的实际效果。试验结果表明,适量的硫、硼营养配合施用对于提高烟叶中石油醚提取物含量有一定的促进作用,当硫素和硼素分别为75、3 kg/hm2时,烤烟不同生育期石油醚提取物含量最高,烘烤后烟叶中部叶石油醚提取物含量为7.84%;6-磷酸葡萄糖脱氢酶、异柠檬酸裂解酶、磷脂酸磷酸酯酶的活性最强。  相似文献   

9.
Resistances of newly bred Bacillus thuringiensis (Bt) crops have been dramatically improved because of the effective and high expression of Bt protein in the plant. However, poorer adaptabilities to environmental stresses were observed in some Bt crops compared to their non‐Bt counterparts. The biological reasons for the poorer adaptabilities were still unclear. A nitrogen (N) deficiency experiment was conducted to investigate variations in growth and physiology characteristics of a newly bred Bt rice [Oryza sativa L. line MH63 (Cry2A*)] compared to its non‐Bt counterpart MH63. MH63 (Cry2A*) showed lower grain yields and lower biomass under low N levels compared to MH63. Earlier leaf senescence associated with disorder in protein metabolism was observed in MH63 (Cry2A*) when the N concentration was lower than 13.50 mg g?1 in MH63 (Cry2A*) leaves and the ratio of Bt protein to soluble protein (BT : SP) was higher than 2203 μg g?1 in MH63 (Cry2A*) leaves. The lower grain yield, the lower biomass and the earlier leaf senescence associated with disorder in protein metabolism in MH63 (Cry2A*) were correlated to the high BT : SP in MH63 (Cry2A*) leaves. The results suggest that MH63 (Cry2A*) has a poorer adaptability to N deficiency compared to its non‐Bt counterpart MH63. This poorer adaptability might be related to the high Bt protein expression in MH63 (Cry2A*).  相似文献   

10.
Abstract

Tomato (Lycopersicon esculentum Mill. var. hybrid 6C‐204) plants were grown for 95 days after germination until each one bore 6 ripe clusters in a greenhouse using nutrient solutions with nine added sulfate levels ranging from 0 to 105 me/1.

Sulfur‐deficiency symptoms and characteristics of plants growing under hign SO4‐S levels were observed and described. Fruit yields were negatively affected by both S‐deficiency and high SO4‐S concentrations. Top growth was affected more than root growth by changes in the amount of SO4‐S supplied. The critical SO4‐S concentration in the growth media ranged from 2 a 22.5 me/1.

Leaf sulfate‐S increased gradually in leaves and roots as SO4‐S supply in the nutrient solution increased while organic‐S remained relatively constant. Leaf sulfate‐S critical value was growth stage dependent. Maximum yields at flowering were associated with leaf concentrations of 0.48–1.2% SO4‐S and 0.25–0.35% organic‐S.  相似文献   

11.
A greenhouse experiment was conducted to study the effect of phosphorus application on the growth of rice and the concentration of P, N, K, Ca, Mg, Fe, Mn, Cu, B and Al in leaves, stems and roots. The results showed that application of phosphorus substantially increased the dry matter of leaves, stems and roots upto 30 ppm of P level. Application of phosphorus caused a decrease in the concentration of Fe, Cu and Al in leaves and stems and increased concentration in roots. Phosphorus concentration increased in all plant fractions, while N and Mn increased in leaves but decreased in stems and roots. Similarly Ca, Mg and B concentration decreased in leaves, stems and roots.  相似文献   

12.
13.
The form of sulfur fertilizer can influence its behavior and crop response. A growth chamber study was conducted to evaluate five sulfur fertilizer forms (ammonium sulfate, ammonium thiosulfate, gypsum, potassium sulfate, and elemental sulfur) applied in seed row at 20 kg S ha?1 alone, and in combination with 20 kg phosphorus pentoxide (P2O5) ha?1, to three contrasting Saskatchewan soils. Wheat, canola, and pea were grown in each soil for 8 weeks and aboveground biomass yields determined. The fate of fertilizer was evaluated by measuring crop sulfur and phosphorus concentration and uptake, and supply rates and concentrations of available sulfate and phosphate in the seed row. Canola was most responsive in biomass yield to the sulfur fertilizers. Sulfate and thiosulfate forms were effective in enhancing soil-available sulfate supplies in the seed row, crop sulfur uptake, and yield compared to the elemental sulfur fertilizer. Combination of sulfur fertilizer with monoammonium phosphate may provide some enhancement of phosphate availability, but effects were often minor.  相似文献   

14.
A field experiment was conducted to assess the effect of sulfur (S) fertilization on distribution of S in soil and use efficiency on blackgram in subtropical Inceptisol of acidic soil of Assam, India. Five levels of S were applied (0, 10, 20, 30 and 40 kg S ha?1) along with recommended dose of nitrogen, phosphorus and potassium. Available S content gradually decreased with the advancement of crop growth stages and lowest value was observed at 60 DAS. Different S fractions were found to increase with increasing levels of S application and 40 kg S ha?1 resulted the highest content for all S fractions. The grain and stover yield of blackgram increased significantly up to 20 kg S ha?1 which was 95.69% higher over control. Agronomic efficiency, apparent S recovery and recovery efficiency of S were higher at 10 kg S ha?1and found decreased with increase in level of S.  相似文献   

15.
Rice plants were grown in solution culture for a period of five weeks at pH's ranging from 3.5 to 8.5. Maximum dry matter was obtained at pH 5.5, but substantial reductions in the growth of tops and roots were observed at pH's of 3.5 and 8.5. At pH 3.5, both leaves and roots were short and unhealthy. The roots were thickened with lateral root growth severely inhibited. At pH 8.5, the youngest leaves developed chlorotic symptoms with roots being coarse and discoloured.

Plant concentrations of essential elements were adequate for normal plant growth at pH 5.5. Iron concentration in plant tops substantially decreased with increase in solution pH, but a reverse trend was observed for roots. The concentrations of other elements progressively increased in plant tops and roots with increasing pH.  相似文献   


16.
We examined the effect of seed nitrogen content on the rates of germination, emergence, and establishment of rice plants. Several seed lots with various nitrogen contents were obtained from the parent plants grown under 3 planting densities and 4 rates of nitrogen application. There was a clear negative correlation between the seed nitrogen content and germination time (R =0.88), whereas the correlation between the seed dry weight and germination time was very low (R=0.23). The seed lot with a high nitrogen content absorbed water faster than the seed lot with a low nitrogen content, especially on the first day after soaking, and also showed a faster emergence, exsertion of the fourth leave, and a more uniform germination. Moreover, the increase of seed nitrogen content as well as the prolongation of soaking time resulted in a uniform emergence. Therefore, seed vigor is likely to be enhanced by the increase of seed nitrogen content, which may be achieved by an adequate application of a large amount of nitrogen to parent plants. Consequently, it may be possible to improve and stabilize the establishment of directly sown rice plants by the sowing of vigorous seeds with a high nitrogen content.  相似文献   

17.
18.
A study was carried out on contribution of iron phosphate to phosphorus nutrition of rice plant under waterlogged and moist conditions,respectively,by use of synthetic Fe^32 PO4.nH2O,tagging directly the iron phophate in calcareous paddy soils.Results showed that under waterlogged condition,similar to iron phosphate in acidic paddy soils.that in clacareous paddy soils was an important source of phosphorus to rice plant ,and the amount of phosphorus originated from it generally constituted 30-65% of the total phosphorus absorbed by rice plant.  相似文献   

19.
Environmental stresses, such as salinity, are becoming critical constraints to plant production especially in arid and semi-arid regions, one of the main targets of agricultural studies is to combat the environmental stresses on plants. An open field experiment was carried out to study the influence of sulfur (S) and urea on red cabbage plants under salt stress. The experiment was arranged as a split-plot design with three replications, the main plots included sulfur levels (0, 350, and 700 kg ha?1), while subplots included urea levels (0, 1, 2, and 4 g L?1). Results showed that urea spraying and sulfur soil additions resulted in improvement of growth and yield, and raised the level of potassium and nitrogen while lowering sodium content in plant leaves under salt stress conditions. Generally, larger and heavier heads were found with the application of 700 kg ha?1 sulfur and 2 g L?1 urea.  相似文献   

20.
Abstract

Monochasma savatieri Franch. ex Maxim is a perennial, parasitic herb used in traditional Chinese medicine and its wild resources have declined sharply in recent years. For a long time, the research on fertilization of parasitic plants mostly focused on parasitic weeds. Despite its urgent need, there are few studies discussing the nutrient requirements of medicinal threatened parasitic plants. In this study, we investigated the growth response of M. savatieri to inorganic solutes. By using an orthogonal design in pot cultivation, the effects of nitrogen, phosphorus, and potassium on growth traits, haustoria formation, and biomass of M. savatieri were determined under greenhouse conditions. The results showed that M. savatieri had a rather significant growth response to different nutrients supplied. Nitrogen, phosphorus, and potassium significantly influenced growth traits, haustoria formation, and biomass of M. savatieri, but differ in the degree. M. savatieri experienced a more significant increase in nitrogen sufficient than phosphorus or potassium sufficient in terms of seedling height (SH), maximum root length, and biomass. There were significant positive correlations between tested parameters. The regression equation for SH, total leaf length, and number of haustoria both showed relatively high R2 values and could be sensitive available indicators. In the absence of hosts and haustoria-inducing factors, M. savatieri was capable of haustoria formation and autotrophic growth for a period of time. We concluded that M. savatieri had a certain demand for inorganic nutrients. The appropriate supply of inorganic nutrients promoted growth and development of M. savatieri.  相似文献   

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