Molecular cloning and characterization of nitrate reductase gene from non-heading Chinese cabbage     

Fei-Fei Sun  Xi-Lin HouYing Li  Xue-Dong Yang 《Scientia Horticulturae》2008

Nitrate reductase (NR) is a key enzyme that catalyzes the first step in plants nitrogen metabolization. A cDNA of a NR gene from non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) cultivar ‘Suzhouqing’ was isolated by RT-PCR and (5′/3′)-RACE techniques. The full-length cDNA sequence of 3049 bp contained an open reading frame of 2733 bp encoding 910 amino acids, a 5′-untranslated region of 113 bp and a 3′-untranslated sequence of 203 bp with a poly (A) tail. This protein shares common structural features with NRs from other higher plants and eukaryotes. It was classified as NR by sequence alignment, motif search and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis, and consequently nominated Brassica campestris ssp. chinensis Makino NR (BcNR). Southern blot analysis indicated that BcNR gene represented as 3 copies in the non-heading Chinese cabbage genome. Accumulation of BcNR mRNA was transiently induced by nitrate supply and correlated with nitrate concentration, the highest mRNA levels of BcNR was induced by 30 mM NO₃⁻ and reached a maximum at 4 h at this optimal concentration treatment, in contrast, NH₄⁺ cannot induce the accumulation of BcNR mRNA. The BcNR was heterologously expressed in Escherichia coli BL21 (DE3) as a fusion protein. There was a specific band at about 110 kDa in size by SDS-PAGE analysis which was according with the expected molecular weight of the recombinant protein. To further explore its biological function, BcNR under regulation of the cauliflower mosaic virus (CaMV) 35S promoter was transferred into Arabidopsis thaliana. The transgenic plants exhibited an enhanced level of NR and nitrate reductase activity (NRA) in leaves under NO₃⁻ inducement.  相似文献   

Responses of cucumber plant to NH₄ and NO₃ nutrition: The relative addition rate technique vs. cultivation at constant nitrogen concentration     

Hamid R. Roosta  Abdoreza Sajjadinia  Asghar Rahimi  Jan K. Schjoerring 《Scientia Horticulturae》2009

Different N sources (NO₃⁻, NH₄⁺, or NH₄NO₃) at different relative addition rates (RAR) were supplied to cucumber (Cucumis sativus L.), a species sensitive to NH₄⁺ toxicity. For comparison, cucumber plants were also grown at constant concentrations of 1 and 5 mM NH₄⁺ or 5 mM NO₃⁻. The fresh weight of NH₄⁺-fed plants at RAR 0.15 and RAR 0.25 day⁻¹ was similar to that of NO₃⁻-fed plants, while at RAR 0.35 or RAR 0.45 day⁻¹ growth reduction occurred. When available as a constant concentration, NH₄⁺ decreased plant growth at 5 mM. It is concluded that at low rates of N supply the relative addition rate technique can be used for growing cucumber plants with NH₄⁺ as sole N source without deleterious effects.  相似文献   

Involvement of a cucumber MAPK gene (CsNMAPK) in positive regulation of ROS scavengence and osmotic adjustment under salt stress     

Huini Xu  Xudong Sun  Xiufeng Wang  Qinghua Shi  Xiaoyu Yang  Fengjuan Yang 《Scientia Horticulturae》2011

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Growth and flowering of black iris (Iris nigricans Dinsm.) following treatment with plant growth regulators     

Nadia M. Al-Khassawneh  Nabila S. KaramRida A. Shibli 《Scientia Horticulturae》2006

The effects of application method and concentration of gibberellic acid (GA₃), paclobutrazol and chlormequat on black iris performance were assessed. Plants (10 cm high, 4 ± 1 leaves) were sprayed with 125, 250, 375 or 500 mg L⁻¹ or drenched with 0.25, 0.5, 1 or 2 mg L⁻¹ GA₃. In a second experiment, the plants were sprayed with 100, 250, 500 or 1000 mg L⁻¹ or drenched with 0.25, 0.5, 1 or 2 mg L⁻¹ paclobutrazol. Other plants were sprayed with 250, 500, 1000 or 1500 mg L⁻¹ or drenched with 100, 250, 375 or 550 mg L⁻¹ chlormequat. In each experiment, the control treatment consisted of untreated plants. Results indicated that the tallest plants (37.3 cm) in the GA₃ experiment were those sprayed with 250 mg L⁻¹. The most rapid flowering (160 days after planting) occurred when a 375 mg L⁻¹ GA₃ spray was used, whereas flowering was delayed to 200 days using 1 mg L⁻¹ GA₃ drench. Drenching with 1 mg L⁻¹ GA₃ increased height of the flower stalk by 7 cm compared to the control. Though relatively slow to flower, plants drenched with 1 mg L⁻¹ GA₃ had long and rigid stalks, which were suitable as cut flowers. Number and characteristics of the sprouts were not affected by GA₃. All paclobutrazol sprays resulted in leaf falcation. A 500 or 1000 mg L⁻¹ paclobutrazol spray resulted in severe and undesirable control of plant height, drastic reduction in stalk height and weight, and delayed flowering. Plants drenched with 0.25 or 1 mg L⁻¹ paclobutrazol were suitable as pot plants. Chlormequat reduced plant height only at the highest drench concentration, which also reduced flowering to 70%. No leaf falcation was observed with GA₃ or chlormequat. Chemical names: ( ± )-(R*,R*)-beta-((4-chlorophenyl)methyl)-alpha-(1,1,-dimethylethyl)-1H-1,2,4,-triazol-1-ethanol (paclobutrazol); (2-chloroethyl) trimethylammonium chloride (chlormequat).  相似文献   

Rapid seedlings regeneration from seeds and vegetative propagation with sucker and rhizome of Eremospatha macrocarpa (Mann & Wendl.) Wendl and Laccosperma secundiflorum (P. Beauv.) Kuntze     

Kouakou Laurent Kouakou  Irié Arsène Zoro Bi  Yao Georges Abessika  Tanoh Hilaire Kouakou  Jean-Pierre Baudoin 《Scientia Horticulturae》2009

To develop efficient seedling production methods for Laccosperma secundiflorum and Eremospatha macrocarpa, a study was conducted to examine regeneration using offsets combined with several physical and chemical treatments of seeds. Offsets categorized into small, medium and large diameters, were planted in three conditions: shaded and open nursery, and greenhouse. We tested sucker from E. macrocarpa, and sucker and rhizome from L. secundiflorum. For both species, high viability percentage (ranging from 55% to 100%) were observed for small and medium suckers planted in shaded nursery and greenhouse, against less than 49% for sucker planted in open nursery. The mean seedling emergence times were estimated to 84, 77 and 75 days after planting (DAP) for small, medium and large sucker of L. secundiflorum, respectively under open nursery condition, and 76, 75, 95 DAP for small, medium and large suckers of the same species, respectively in shaded condition. Greenhouse has a significant positive effect on E. macrocarpa seedlings emergence time. For this species, the mean seedling emergence times were estimated to 43 DAP for small sucker and 76, 93 DAP for medium and large suckers. No seedling was obtained from rhizome planted in all the growing conditions tested. Concerning seed dormancy breaking, germination percentages and rates were determined for 13 treatments. The best treatments were pre-soaking unscarified seeds for 4 days in 1.01 g l⁻¹ and 0.10 g l⁻¹ KNO₃, with 79% and 68% of germination, respectively and in 3.46 × 10⁻³ g l⁻¹ GA₃ for 68% of germination. These methods are suggested to improve germination of L. secundiflorum seeds. Successful and recommended methods for E. macrocarpa are pre-soaking scarified seeds in 3.46 × 10⁻³ g l⁻¹ and 3.46 × 10⁻⁴ g l⁻¹ GA₃, 96% and 94% of germination, respectively. Dormancy, probably a combination of mechanical and chemical dormancy, is present in the two species.  相似文献   

Determination of the uptake and translocation of nitrogen applied at different growth stages of a melon crop (Cucumis melo L.) using N isotope     

M.J. Cabello  M.T. Castellanos  A.M. Tarquis  M.C. Cartagena  A. Arce  F. Ribas 《Scientia Horticulturae》2011

In order to establish a rational nitrogen (N) fertilisation and reduce groundwater contamination, a clearer understanding of the N distribution through the growing season and its dynamics inside the plant is crucial. In two successive years, a melon crop (Cucumis melo L. cv. Sancho) was grown under field conditions to determine the uptake of N fertiliser, applied by means of fertigation at different stages of plant growth, and to follow the translocation of N in the plant using ¹⁵N-labelled N. In 2006, two experiments were carried out. In the first experiment, labelled ¹⁵N fertiliser was supplied at the female-bloom stage and in the second, at the end of fruit ripening. Labelled ¹⁵N fertiliser was made from ¹⁵NH₄¹⁵NO₃ (10 at.% ¹⁵N) and 9.6 kg N ha⁻¹ were applied in each experiment over 6 days (1.6 kg N ha⁻¹ d⁻¹). In 2007, the ¹⁵N treatment consisted of applying 20.4 kg N ha⁻¹ as ¹⁵NH₄¹⁵NO₃ (10 at.% ¹⁵N) in the middle of fruit growth, over 6 days (3.4 kg N ha⁻¹ d⁻¹). In addition, 93 and 95 kg N ha⁻¹ were supplied daily by fertigation as ammonium nitrate in 2006 and 2007, respectively. The results obtained in 2006 suggest that the uptake of N derived from labelled fertiliser by the above-ground parts of the plants was not affected by the time of fertiliser application. At the female-flowering and fruit-ripening stages, the N content derived from ¹⁵N-labelled fertiliser was close to 0.435 g m⁻² (about 45% of the N applied), while in the middle of fruit growth it was 1.45 g m⁻² (71% of the N applied). The N application time affected the amount of N derived from labelled fertiliser that was translocated to the fruits. When the N was supplied later, the N translocation was lower, ranging between 54% at female flowering and 32% at the end of fruit ripening. Approximately 85% of the N translocated came from the leaf when the N was applied at female flowering or in the middle of fruit growth. This value decreased to 72% when the ¹⁵N application was at the end of fruit ripening. The ammonium nitrate became available to the plant between 2 and 2.5 weeks after its application. Although the leaf N uptake varied during the crop cycle, the N absorption rate in the whole plant was linear, suggesting that the melon crop could be fertilised with constant daily N amounts until 2–3 weeks before the last harvest.  相似文献   

Effect of nitrogen form and radiation on growth and mineral concentration of two Brassica species     

C. Fallovo  G. Colla  M. Schreiner  A. Krumbein  D. Schwarz 《Scientia Horticulturae》2009

Three greenhouse experiments were carried out to determine the growth, yield, nitrate, total N and S concentration in shoots, and water uptake of hydroponically grown Brassica rapa L. subsp. nipposinica var. chinoleifera and Brassica juncea L. In each experiment, daily photosynthetically active radiation (PAR) level was 5.0 mol m⁻² (low), 6.8 mol m⁻² (medium) or 9.0 mol m⁻² (high). Plants were supplied with nutrient solutions having equal N concentrations of 11 mM in different forms: 100% NH₄, 50% NH₄ + 50% NO₃, and 100% NO₃. Nitrogen supplied as 100% NH₄ reduced fresh and dry shoot biomass, leaf area, and leaf number in both Brassica species, especially at low and medium PAR levels. In both Brassica species, S concentrations were highest, while nitrate concentrations were lowest in leaves of plants grown at N supplied as 100% NH₄. No differences in leaf nitrate concentrations were observed between 50% NH₄ + 50% NO₃ and 100% NO₃ treatments. Low and high PAR levels increased the nitrate concentrations and decreased the N/S ratio in leaves of both crops compared to medium PAR level. Fresh shoot biomass was maximized in Brassica rapa when PAR level was above the medium value and nitrate was supplied in the nutrient solution as NO₃ or as a mixture of 50% NO₃ and 50% NH₄. The highest fresh shoot biomass of Brassica juncea was observed in all nutrient solution treatments at high PAR level.  相似文献   

High frequency early flowering from in vitro seedlings of Dendrobium nobile     

Z.H. Wang  L. Wang  Q.S. Ye 《Scientia Horticulturae》2009

Dendrobium nobile Lindl. is a popular temperate Chinese orchid commonly marketed as a traditional medicinal plant. Seedlings of Dendrobium nobile Lindl. produced floral buds (33.3–34.8%) precociously on a defined basal medium (1/2 MS) containing paclobutrazol (PP₃₃₃) at 0.5 mg L⁻¹ or thidiazuron (TDZ) at 0.1 mg L⁻¹ within 4 months of culturing. The frequency of floral buds formation can be further increased to 95.6% by growing seedlings in a PN (PP₃₃₃ 0.3 mg L⁻¹ + NAA 0.5 mg L⁻¹)-containing medium followed by transfer onto 1/2 MS medium with PP₃₃₃ and TDZ (PP₃₃₃ + TDZ). However, flower developed was deformed under 25 °C but it developed fully when grown in a lower temperature regime (23 °C/18 °C, light/dark) for 45 days. Under optimal condition, in vitro flowering was observed about 6 months after seed sowing.  相似文献   

Cucumber fruit quality at harvest affected by soilless system,crop age and preharvest climatic conditions during two consecutive seasons     

M.D. Gómez-López  J.P. Fernández-Trujillo  A. Baille 《Scientia Horticulturae》2006

Cucumber fruits (Cucumis sativus L., cv. Trópico F1) grown on perlite substrate and NFT (Nutrient Film Technique) were harvested during two seasons (winter and spring) to monitor the effects of climatic conditions and hydroponic growth systems on fruit quality at harvest. The best fruit quality at harvest, as measured by lightness and hue angle parameters, was obtained during the 3 weeks following the first winter picking. When values of a parameter of preharvest climate value called G^* were lower than 0.4 MJ m⁻² °C day⁻¹ interval⁻¹, the cucumber achieved its optimum quality at harvest, as measured by the dark green color of the skin. NFT-grown fruits showed darker and greener skin color (higher hue angle and lower lightness) compared with perlite-grown fruit, irrespective of the season considered. During the winter season, the plant transpiration rate was 30% higher in perlite than in NFT culture, which correlates with higher differences in G^* and 40% additional yield in perlite. However, in spring G^* was not sensitive enough to discriminate between the two hydroponic systems. In general, fruit quality at harvest in spring was lower than during the winter, due to flesh whitening, higher longitudinal and equatorial calibers, and slightly higher pH, as well as worse epidermal color coordinates (ranging from the dark and dull green color typical of winter fruit to light and a vivid green-yellow color). During the spring season, NFT-grown fruit were less acid than perlite-grown fruit with no apparent correlation with the climatic conditions or fruit nutrition.  相似文献   

Effects of leaf aging and light duration on photosynthetic characteristics in a cucumber canopy   总被引：1，自引：0，他引：1  

Rolf I. Pettersen  Sissel TorreHans R. Gislerød 《Scientia Horticulturae》2010

Photosynthetic characteristics, chlorophyll index and leaf area were examined in selected leaves of cucumber (Cucumis sativus L. cv. Euphorbia). In the first experiment, plants of cucumber were grown horizontally at a lighting period of 20 h day⁻¹. Photosynthetic measurements in horizontally growing cucumbers showed that there was no decline in photosynthetic capacity when cucumber leaves are developing under good light conditions. In a second experiment, plants were grown in a traditional high-wire cultivation system under 20 h day⁻¹ lighting period until they reached final height and then exposed to different lighting periods (20 and 24 h day⁻¹) for 3 weeks. In stands of cucumber plants photosynthetic measurements showed that the lower leaves have a significant reduction in photosynthetic capacity due to reduced light conditions. Three weeks exposure to 24 h day⁻¹ lighting period reduced leaf area by 20%. Plant grown under continuous light had also lower chlorophyll index compared to plants grown under 20 h day⁻¹ lighting period.  相似文献   

CO₂ and air circulation effects on photosynthesis and transpiration of tomato seedlings     

P. Thongbai  T. Kozai  K. Ohyama 《Scientia Horticulturae》2010

In the daytime, a CO₂ depletion of 10–15% and air circulation of less than 0.5 m s⁻¹ often occur in a naturally ventilated greenhouse during a sunny day with high wind speed (3–5 m s⁻¹). We, therefore, investigated the effects of moderate increase of the CO₂ concentration above the atmospheric level (500–600 μmol mol⁻¹) and air circulation up to 1.0 m s⁻¹ in a growth chamber on the net photosynthetic and transpiration rates of tomato seedlings as the first step. The average net photosynthetic rates were 2.1, 1.8, and 1.6 times higher in the growth chambers with increased CO₂ concentration (500–600 μmol mol⁻¹) and air circulation (1.0 m s⁻¹), increased CO₂ concentration, and increased air circulation, respectively, compared with those in the control (no increase in CO₂ concentration (200–300 μmol mol⁻¹) or air circulation (0.3 m s⁻¹). The transpiration rate increased with increased air circulation, while it decreased with increased CO₂ concentration regardless of air circulation. From the results, we consider that increasing the CO₂ concentration and/or air circulation in ventilated greenhouses up to the outside concentration (350–450 μmol mol⁻¹) and 1.0 m s⁻¹, respectively, can significantly increase the net photosynthetic rate of greenhouse plants.  相似文献   

Production of inter-section hybrids between Primula filchnerae and P. sinensis through ovule culture     

Junji Amano  Juntaro Kato  Masaru Nakano  Masahiro Mii 《Scientia Horticulturae》2006

Inter-section hybrids were obtained in the reciprocal crosses between Primula filchnerae (2n = 2x = 24) of Sect. Pinnatae and P. sinensis ‘Fanfare’ (2n = 2x = 24) of Sect. Auganthus by rescuing ovules on half-strength (1/2) Murashige and Skoog's (MS) medium supplemented with 50 g l⁻¹ sucrose, 2.5 g l⁻¹ gellan gum, 0.1 mg l⁻¹ α-naphthaleneacetic acid (NAA), 0.1 mg l⁻¹ 6-benzyladenine (BA) and 50 mg l⁻¹ gibberellic acid (GA₃). In ovule culture, germination occurred with radicle elongation but no plumule was observed. The radicle kept on the initial medium showed root proliferation with callus formation. When the calluses were transferred to (1/2)MS media containing 30 g l⁻¹ sucrose and 3 g l⁻¹ gellan gum, without plant growth regulators (PGRs) or with 1 mg l⁻¹ zeatin and 0.1 mg l⁻¹ NAA, plantlets were regenerated. The plants thus obtained were confirmed to be hybrids through flow cytometry (FCM) and random amplified polymorphic DNA (RAPD) analyses. The hybrid obtained when P. filchnerae was used as the maternal parent was diploid, whereas hexaploid hybrid was obtained when using P. sinensis as the maternal parent. The hexaploid hybrid might be produced through chromosome doubling of a triploid originated from the fertilization of P. sinensis with unreduced pollen of P. filchnerae.  相似文献   

Exogenous paraquat changes antioxidant enzyme activities and lipid peroxidation in drought-stressed cucumber leaves     

Zhong-Jing Liu  Xiao-Long Zhang  Ji-Gang Bai  Bang-Xia Suo  Pei-Lei Xu  Lin Wang 《Scientia Horticulturae》2009

In order to examine whether paraquat modifies the functioning of antioxidants and oxidative stress levels in drought-stressed plants, a cucumber cultivar (Cucumis sativus cv. Yuexiu no. 3) was grown hydroponically for 2 days. Drought stress, which was induced by polyethylene glycol (PEG), increased the contents of malonaldehyde (MDA), superoxide radical (O₂⁻) and hydrogen peroxide (H₂O₂) in cucumber leaves, while pretreatment of paraquat decreased them. Under drought stress induced by PEG, we observed the decreased contents of MDA, H₂O₂ and O₂⁻ in paraquat-pretreated plants in comparison to unpretreated stressed plants. Drought stress and paraquat both increased the activities of antioxidants such as superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), guaiacol peroxidase (GPX, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11), dehydroascorbate reductase (DHAR, EC 1.8.5.1), monodehydroascorbate reducatase (MDHAR, EC 1.6.5.4), glutathione reductase (GR, EC 1.6.4.2), reduced glutathione (GSH) and reduced ascorbate (AsA). But the combined effect of paraquat application and drought stress resulted in the highest activities of antioxidants. So paraquat is able to moderate the activities of scavenging system enzymes and to influence oxidative stress intensity under drought stress induced by PEG.  相似文献   

Exogenous hydrogen peroxide influences antioxidant enzyme activity and lipid peroxidation in cucumber leaves at low light     

Xiao-Long Zhang  Xue-Fei Jia  Bin Yu  Yang Gao  Ji-Gang Bai 《Scientia Horticulturae》2011

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The effect of various nitrogen fertilization and foliar nutrition regimes on the concentrations of nitrates,ammonium ions,dry matter and N-total in carrot (Daucus carota L.) roots     

Sylwester Smoleń  Włodzimierz Sady 《Scientia Horticulturae》2009

Two field experiments (Experiment I in 2003–2005 and Experiment II in 2004–2005) with carrot c.v. ‘Kazan F₁’ were conducted at Trzciana village (50°06′N, 21°85′E). The experiments were arranged in a split-plot design with four replications. Two sub-blocks were identified in both experiments: I, without foliar nutrition; II, receiving plant foliar nutrition. The plants were sprayed three times alternately with: 2% urea solution, 1% solution of multi-component ‘Supervit R’ fertilizer (produced by Intermag, Poland) and again with 2% urea solution. Combinations with diversified nitrogen fertilization were distinguished within both sub-blocks. Experiment I comprised of: (1) Control, (2) Ca(NO₃)₂ 70, (3) Ca(NO₃)₂ 70 + 70, (4) (NH₄)₂SO₄ 70 and (5) (NH₄)₂SO₄ 70 + 70. Experiment II included: (1) Control, (2) ENTEC-26 35 + 35, (3) ENTEC-26 70 + 70, (4) ENTEC 26 105 + 105, (5) NH₄NO₃ 35 + 35, (6) NH₄NO₃ 70 + 70, (7) NH₄NO₃ 105 + 105. Where 70 kg N ha⁻¹ was used before sowing, whereas 35 + 35, 70 + 70 and 105 + 105 kg N ha⁻¹ were applied before sowing and as top dressing. Solid nitrogen fertilizer was added to the soil (produced by): Ca(NO₃)₂, Yara International ASA (Hydro); (NH₄)₂SO₄, Zak?ady Azotowe in Tarnów, Poland; NH₄NO₃, Zak?ady Azotowe in Pu?awy, Poland; and ENTEC-26, COMPO GmbH & Co. KG, Germany. The research aimed at determining the effect of diversified nitrogen fertilization and foliar nutrition on NO₃⁻, NH₄⁺, N-total and dry matter (d.m.) concentrations in carrot, and N uptake by storage roots. In Experiment I, nitrogen fertilization did not affect NO₃⁻ concentration, whereas in Experiment II, the applied N treatment increased NO₃⁻ concentration in carrot in relation to the control, except for the storage roots of plants fertilized with ENTEC-26 35 + 35. Nitrogen fertilization applied in both experiments caused a significant increase in N-total concentration in carrot and N uptake by storage roots in comparison with the control plants. In both experiments, nitrogen fertilization had a different effect on the concentrations of NH₄⁺ and d.m. in carrot. What is more, foliar nutrition treatments in both experiments had a different effect on the concentrations on NO₃⁻, N-total, d.m. in carrot and N uptake by carrot storage roots.  相似文献   

The effect of nitrogen source and concentration,medium pH and buffering on in vitro shoot growth and rooting in Eucalyptus marginata     

A.J. Woodward  I.J. Bennett  S. Pusswonge 《Scientia Horticulturae》2006

This work examined the effect of nitrogen source and medium buffering on the micropropagation of Eucalyptus marginata Donn ex Sm. The number of shoots was increased when media contained 2-(N-morpholino) ethanesulfonic acid (MES) but this increase was minor and only applied to one of the two clones tested. Highest root production was obtained when the medium contained 7.5 mM nitrogen in a ratio of 2NO₃⁻:1NH₄⁺ and was buffered with 10 mM MES. In the rooting medium the pH was influenced most significantly by the nitrogen source, and then whether the medium was buffered. The media pH remained relatively constant when nitrate was the sole nitrogen source and this was assisted by the addition of 10 mM MES. Lower concentrations (<10 mM) of MES were less effective in buffering media over a four-week culture period in both shoot multiplication and rooting medium.  相似文献   

Effect of different fertilisation and irrigation practices on yield,nitrogen uptake and fertiliser use efficiency of white cabbage (Brassica oleracea var. capitata L.)     

Martina Šturm  Nina Kacjan-Maršić  Vesna Zupanc  Branka Bračič-Železnik  Sonja Lojen  Marina Pintar 《Scientia Horticulturae》2010

The effect of different fertilisation (i.e. broadcast application and fertigation) and irrigation practices (tank sprinkler and drip irrigation) on yield, yield quality (nitrate content), nitrogen uptake of white cabbage (Brassica oleracea var. capitata L.) and the potential for N losses was assessed on sandy-loam agricultural soil. ¹⁵N-labelled fertiliser was used as a tracer. It was found that different practices significantly affected yield, nitrate content in plants, N uptake, as well as fertiliser use efficiency. The highest yield (93 t ha⁻¹), plant N uptake (246 kg ha⁻¹), and fertiliser use efficiency (42%) were obtained under treatment with broadcast fertilisation with farmer's practice of irrigation (tank sprinkler). The N surplus after harvest was −41 kg N ha⁻¹, indicating the lowest potential for N losses. Treatment by fertigation and drip irrigation covering 100% of the crop's water requirements did not result in the highest yield as expected (72 t ha⁻¹), the N surplus after harvest was about +38 kg ha⁻¹. The lowest yield (58 t ha⁻¹), fertiliser use efficiency (30%) and hence the highest potential for N losses (N surplus after harvest +68 kg ha⁻¹) were found in treatment with broadcast fertilisation and drip irrigation covering 50% of the crop's water requirements.  相似文献   

The effect of various nitrogen fertilization and foliar nutrition regimes on the concentrations of sugars,carotenoids and phenolic compounds in carrot (Daucus carota L.)     

Sylwester Smoleń  Włodzimierz Sady 《Scientia Horticulturae》2009

The aim of this research was to determine the influence of various forms, diverse doses, and dates of application of nitrogen fertilizers and foliar nutrition on the concentration of sugars, carotenoids and phenolics compound in carrot. Two field experiments (Experiment I in 2003–2005 and Experiment II in 2004–2005) with carrot ‘Kazan F₁’ were conducted in Trzciana (50°06′N; 21°85′E) in Poland. Both experiments were arranged in a split-plot design with four replications. Two sub-blocks were identified in both experiments: sub-block (A) without foliar nutrition and sub-block (B) with plant foliar nutrition. In sub-block (B), plants were sprayed three-times with: 2% (w/v) urea, a 1% (v/v) solution of multi-component ‘Supervit R’ fertilizer, and again with 2% (w/v) urea. Combinations with diversified nitrogen fertilization were distinguished within both sub-blocks. The treatments in Experiment I consisted of: (1) Control, (2) 70 kg N ha⁻¹ as Ca(NO₃)₂, (3) 70 + 70 kg N ha⁻¹ as Ca(NO₃)₂, (4) 70 kg N ha⁻¹ as (NH₄)₂SO₄ and (5) 70 + 70 kg N ha⁻¹ as (NH₄)₂SO₄, where 70 kg N ha⁻¹ was used preplant and 70 + 70 kg N ha⁻¹ was applied preplant and as a top dressing, respectively. The treatments in Experiment II consisted of: (1) Control, (2) 35 + 35 kg N ha⁻¹ as ENTEC-26, (3) 70 + 70 kg N ha⁻¹ as ENTEC-26, (4) 105 + 105 kg N ha⁻¹ as ENTEC-26, (5) 35 + 35 kg N ha⁻¹ as NH₄NO₃, (6) 70 + 70 kg N ha⁻¹ as NH₄NO₃, (7) 105 + 105 kg N ha⁻¹ as NH₄NO₃, where 35 + 35, 70 + 70, 105 + 105 kg N ha⁻¹ was applied preplant and as top dressing, respectively. Solid nitrogen fertilizer was added to the soil, as produced: Ca(NO₃)₂—Yara International ASA (Hydro), (NH₄)₂SO₄—Zak?ady Azotowe w Tarnowie, Poland, NH₄NO₃—Zak?ady Azotowe w Pu?awach, Poland and ENTEC-26–COMPO GmbH & Co., KG, Germany. In Experiment I, the highest sugar concentrations were found in carrot fertilized with (NH₄)₂SO₄ 70, while in Experiment II in the control and after fertilization with ENTEC-26 35 + 35 kg N ha⁻¹. In both experiments N-fertilization affected an increase in phenolic compound concentrations in comparison with the control. Experiment I revealed no significant effect of N-fertilization on carotenoid concentrations in carrot, however in Experiment II the highest concentration of these compounds was characteristic for the control plants and carrot fertilized with ENTEC-26 35 + 35. The foliar nutrition applied in Experiment I caused a decline in sugar concentration and an elevated carotenoid concentration, however it had no influence on the phenolic compound concentrations in carrot. Yet the foliar nutrition in Experiment II led to a decrease in phenolic and carotenoid compound concentrations, but it did not affect sugar concentration in carrot.  相似文献   

Copper distribution and ionic form effects for postharvest treatments of cut Acacia holosericea stems     

Kamani Ratnayake  Chuc L. Bui  Daryl C. Joyce 《Scientia Horticulturae》2011

A short postharvest life is the major constraint associated with cut Acacia flowers and foliage. Treatment with CuSO₄ (Cu²⁺) has previously been shown to improve the longevity of cut Acacia holosericea stems. Towards refining the treatments, a range of Cu²⁺ and Cu⁺ salts were assessed for relative efficacy in improving vase life and water relations of A. holosericea. Five hour pulses with the Cu²⁺ salts CuSO₄, CuCl₂, (CH₃COO)₂Cu and Cu(NO₃)₂ at 2.2 mM gave equally longer vase lives by ∼2.5-fold over deionised water (DIW) and standard tap water (STW) controls. The same Cu²⁺ salts at 0.5 mM in the vase solution also gave significantly (P < 0.05) improved vase life, relative fresh weight and water uptake compared to the DIW control. For Cu²⁺ versus Cu⁺, optimum concentrations with Cu²⁺ could not be directly compared due to the low solubility of the Cu⁺ salt CuCl. However, Cu⁺ from CuCl at 0.415 mM also had positive effects on vase life compared to the DIW control. Thus, both Cu²⁺ and Cu⁺ treatments can enhance vase life parameters for cut A. holosericea foliage. The benefits were irrespective of the counter ion and, thus, Cu²⁺ and Cu⁺per se were responsible. The most effective Cu²⁺ pulse treatment decreased stomatal conductance of phyllodes initially, but did not cause sustained stomatal closure. Cu accumulated to greater levels in basal stem and phyllode tissues than in upper stem and phyllode tissues of cut A. holosericea stems. Possible mechanisms of Cu²⁺/Cu⁺ action are discussed.  相似文献   

Identification of low-light induced genes in cucumber (Cucumis sativus) seedlings by suppression subtractive hybridization     

G.Q. Mi  L.Y. Liu  J.W. Dang  Z.X. Zhang  H.Z. Ren 《Scientia Horticulturae》2008

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