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.
以大白菜[Brassica pekinensis(Lour.)Olsson]中结球小的类型‘金娃娃’品种为试验材料,采用水培的方法,研究了正常光(200μmol·m~(-2)·s~(~(-1)))和弱光(100μmol·m~(-2)·s~(-1))下营养液中不同铵硝配比(0︰100、10︰90、15︰85和25︰75;总N浓度为5 mmol·L~(-1))氮素对幼苗生长以及叶片生理生化特性的影响。处理14 d后,正常光下,铵硝配比15︰85的处理植株长势最佳,较全硝态氮处理叶面积、株幅、鲜质量和干质量分别显著提高了33.8%、30.5%、77.9%和72.9%。弱光抑制了幼苗的生长,植株叶面积、株幅和干鲜质量均低于正常光下生长的植株。弱光下幼苗叶片丙二醛(MDA)、超氧阴离子、过氧化氢(H2O2)含量明显升高,植株遭受膜脂过氧化程度较高。铵硝配比10︰90处理较全硝态氮处理相比,植株叶面积、株幅、鲜质量和干质量分别显著提高了20.4%、14.9%、55.9%和36.5%,而且显著提高叶片的可溶性糖和可溶性蛋白含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,降低MDA和超氧阴离子含量,有效地抑制了膜脂过氧化。正常光条件下,铵硝配比为15︰85时植株长势最佳;弱光下,铵硝配比为10︰90时植株长势最佳,可降低膜脂过氧化物质含量、提高抗氧化酶活性和渗透调节物质含量,进而提高幼苗耐弱光性。  相似文献   

2.
The purpose of this study was to investigate the mechanisms underlying alleviation of salt stress by arbuscular mycorrhizal fungi Glomus mosseae. Tomato (Lycopersicon esculentum L. cv. Zhongzha105) plants were cultivated in soil with 0, 50 and 100 mM NaCl. Mycorrhization alleviated salt induced reduction of root colonization, growth, leaf area, chlorophyll content, fruit fresh weight and fruit yield. The concentrations of P and K were higher in AM compared with nonAM plants grown under nonsaline and saline conditions. Na concentration was lower in AM than nonAM plants grown under nonsaline and saline conditions. AMF colonization was accompanied by an enhancement of activity of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in leaves of both salt-affected and control plants. In addition, inoculation with AMF caused reduction in MDA content in comparison to salinized plants, indicating lower oxidative damage in the colonized plants.  相似文献   

3.
The aim of this study was to evaluate the effects of low molecular mass antioxidants and NaCl salinity on growth, ionic balance, proline, and water contents of ‘Zard’ olive trees under controlled greenhouse conditions. The experiment was carried out by spraying 2 mM of ascorbic acid (Asc) and 3 mM of reduced glutathione (GSH) on the plants that were treated with two salinity levels (0 and 100 mM NaCl) on their root medium. Plant growth parameters (leaf fresh weight, leaf dry weight, leaf number, total fresh weight, and total dry weight) were significantly improved by Asc compared with growth parameters in GSH and control plants. Higher concentrations of Na+ and Cl were observed in salt-stressed plants, while Na+ and Cl concentrations were decreased in the olive leaves that were sprayed with Asc. Salinity in the root zone caused a considerable decline in both K+ concentration and K/Na ratio. K+ concentration and K/Na ratio were significantly increased by application of Asc on plant leaves. Salinity caused an increase in electrolyte leakage (EL) compared with the control plants. Lowest EL and tissue water content (TWC) was obtained in Asc-sprayed plants, whereas TWC was increased in salt-stressed plants. Plants were subjected to salt stress and showed a higher relative water content (RWC) than the control plants. Salt stress induced proline accumulation in olive leaves. In conclusion, exogenous application of Asc is recommended to improve tolerance of olive plants under saline conditions.  相似文献   

4.
Effect of nickel (Ni) in the nutrient solution on yield, N metabolism, and nitrate content of leafy vegetables is poorly understood. The aim of this nutrient solution culture experiment was to investigate the effects of Ni supplementation on the nitrogen (N) metabolism and growth of lettuce (Lactuca sativa L. cv. Baker) with either urea or nitrate as the N source. Nickel supplement at 0.04 μM reduced urea toxicity to the urea-fed plants. Addition of Ni to the nutrient solution significantly increased the leaves and root growth of the urea-fed lettuce plants while it increased the growth of lettuce plants fed with nitrate only at N level of 20 mM. At N level of 20 mM, the leaves fresh weight of the urea-fed plants promoted by Ni supplement was comparable with the nitrate-fed plants untreated with Ni. Nickel supplementation increased the leaf total N concentrations in the urea-fed plants, although the nitrate-fed plants accumulated greater N in their leaves compared with urea treated plants at without Ni treatment. Nickel addition decreased the concentrations of leaf urea-N in the urea-fed plants and NO3-N in the nitrate-fed plants. Nickel addition enhanced urease activity in the leaves of urea-fed plants. The results indicated Ni supplementation enhances the growth of the urea-fed lettuce plants while it has role in decreasing leaf nitrate concentration and thus, improving the health quality of the nitrate-fed plants.  相似文献   

5.
钼对小白菜叶色、营养品质及硝酸盐含量的影响   总被引:6,自引:2,他引:4  
以小白菜(五月慢)为供试材料,采用盆栽的方法,研究施钼水平对小白菜叶色、营养品质及硝酸盐含量的影响。结果表明,施钼能够促进小白菜生长,提高其产量;施钼可以提高小白菜叶绿素含量,使叶色更为浓绿;施钼显著增加了小白菜钼、抗坏血酸、可溶性糖、可溶性蛋白质、部分人体必需氨基酸及非必需氨基酸的含量,改善其营养品质;施钼能够显著降低小白菜硝酸盐含量,在一定程度上提高了小白菜的食用安全性;本试验中,钼水平以0.300 mg·kg-1效果最好。  相似文献   

6.
庞敏晖  高利娟  左强  宋大平 《蔬菜》2020,(11):23-28
为实现蔬菜有机废弃物循环利用,探索绿色种植技术,解决有机蔬菜种植追肥难题,通过盆栽试验,设置有机肥单施、有机肥与发酵液配施、有机肥与化肥配施等处理,研究蔬菜废弃物制备发酵液对快菜生长发育、产量品质、养分吸收等方面的影响。结果表明:蔬菜废弃物制备发酵液在促进作物生长、提高产量、改善品质等方面均有一定的作用。与有机肥单施相比,追施发酵液后快菜的株高、最大叶长、最大叶宽分别增大了20.5%、7.0%、6.2%,单株鲜质量、单株干质量分别提高了74.7%和6.7%,硝酸盐含量降低了47.1%,快菜中氮、磷、钾养分含量分别增加了74.4%、28.6%、153.5%;但施入发酵液后,快菜植株内的VC含量有所降低。蔬菜废弃物发酵液可部分替代化肥,且与有机肥配合施用效果更好。  相似文献   

7.
为了解铅对油麦菜和四季菜心生长的影响,通过无土栽培的方法,用不同浓度的硝酸铅溶液对2种植物的幼苗进行了胁迫处理,分析不同浓度铅处理对植物生长的影响。结果表明:铅处理不同程度的影响了2种植物的生长,降低了其生长速度。但是,除茎叶鲜重和干重外,各指标仍呈现增加趋势。在相同处理时间内,高浓度的铅处理使油麦菜叶片数、叶面积、株高和茎叶鲜重、干重指标明显下降,根系鲜重、干重则呈增加趋势。在高浓度铅处理下,四季菜心的各项指标呈现降低趋势。在0.005mg/L的铅处理时,四季菜心各项指标略好于对照,油麦菜各项指标则略有降低;表明在低浓度下油麦菜对铅更敏感。在0.015mg/L处理时,油麦菜和四季菜心各项生长指标均明显降低,四季菜心降低的更多;在0.045mg/L铅高浓度处理下,油麦菜和四季菜心各项指标变化最大,生长受到明显抑制;高浓度铅对四季菜心的生长影响更大。  相似文献   

8.
《Scientia Horticulturae》2001,89(2):143-154
The effectiveness of two commercial formulations of gibberellin (GA) and benzyladenine (BA) for reducing foliar chlorosis on Easter lily (Lilium longiflorum Thunb.) was compared. On a per liter basis, plants were sprayed with 0, 100, 200, or 400 mg (BA equivalent) of Accel (GA4+7:BA of 1:10) or Promalin (GA4+7:BA of 1:1) when the crop leaf area index (LAI)=3. One group of plants was sprayed with 100 mg of Accel or Promalin (BA equivalent) per liter twice: once at LAI=3 and again 3 weeks later. Plants were harvested when the largest flower bud on each plant measured 13 cm in length, stored for 0 or 3 weeks at 2.5°C in the dark, and then moved into a post-harvest evaluation room at 21°C, where foliar chlorosis was monitored for 3 weeks. Senescence of some lower leaves on plants in every treatment was evident at harvest, and incidence of senescence increased during the 21 days of post-harvest evaluation. Cold storage increased the number of leaves senescing during the subsequent evaluation period. Application of Promalin or Accel significantly reduced leaf senescence compared to that of untreated plants. At harvest, 21% of the leaves on untreated plants were senescent, while plants treated with Promalin or Accel averaged 3 or 9% senescent leaves, respectively. Following 7 days of post-harvest evaluation, Promalin was more effective in preventing chlorosis than Accel at the 400 mg l−1 (BA equivalent) level. Following 14 or 21 days of post-harvest evaluation, Promalin was more effective than Accel for the 100 mg l−1 2× and 400 mg l−1 (BA equivalent) treatments.Plants in all Promalin and Accel treatments were taller than untreated plants 1 week after sprays were applied. At harvest, plants sprayed with Promalin were between 6 and 14 cm taller than untreated plants, but those treated with Accel were the same height as untreated plants.Neither Promalin nor Accel influenced the occurrence of malformed or aborted flowers in this study. However, cold storage significantly increased the number of plants with aborted buds and malformed flowers. Unstored plants averaged 0.16 aborted buds and 0.02 malformed flowers each, while those stored 3 weeks averaged 0.51 aborted buds and 0.18 malformed flowers each.  相似文献   

9.
Summary

Field-grown rockmelon plants were treated with -aminobutyric acid (BABA), 2,6-dichloroisonicotinic acid (INA), benzothiadiazole (BTH) or water during fruit development and evaluated for increased resistance against plant diseases or post-harvest pathogens. One experiment was conducted at Camden, NSW, Australia (INA, BABA or water). Two experiments were at Griffith, NSW, Australia (INA, BTH or water). Growing plants and harvested fruits were assessed for disease symptoms from natural infections and assayed for the accumulation of chitinase and peroxidase, two major pathogenesis-related (PR) proteins induced as a result of systemic acquired resistance (SAR). Harvested fruit from both BTH- or INA-treated plants showed a significant (P < 0.05) reduction in the severity and incidence of post-harvest storage diseases mainly caused by Fusarium, Alternaria and Rhizopus. However, there were no differences in disease severity and the incidence of rots between using four fortnightly foliar sprays of INA or BTH during flowering and fruit development, or a single spray of BTH, 2 weeks before harvest. Each approach showed an equivalent reduction in storage diseases. Plants treated with BABA showed less resistance against powdery mildew in the field and storage rots from natural inoculum, and lower increases in chitinase and peroxidase activities than those treated with INA. In all trials, an additional post-harvest dip with guazatine [0.05% (w/v)] gave a substantial reduction in melon storage rots. Pre-harvest application of INA or BTH reduced the occurrence of powdery mildew and downy mildew on the leaves. Over the three field-experiments, INA had a small phytotoxic effect causing lesion-like symptoms on leaves and affected plant growth, but not yield, at Camden, when applied during flowering and 2 weeks after flowering. However, INA did not produce any phytotoxic effects in the two experiments at Griffith when applied serially, four times to plants after flowering.  相似文献   

10.
不同遮荫度对鼠尾草生长的影响   总被引:1,自引:0,他引:1  
研究了不同遮荫水平(0%、50%、70%、90%)对鼠尾草生长的影响.结果表明:遮荫程度的加重,鼠尾草现蕾、开花的日期延后,开花持续的时间缩短.在开花期,随着遮荫度的增加,植株高度、花序长度、花梗长度降低,叶片长度、叶片宽增加,而整个植株、植株的地上部分及根系的鲜重和干重减少.遮荫处理的叶片数与对照处理的没有显著差异.可见,光照充足有利于鼠尾草的生长和花期的延长.  相似文献   

11.
为探究不同氮处理对番茄植株叶片养分的影响及增施CO2的效果。以番茄"鸿途"为试验材料,在2个自然光照人工气候室内,采用苗钵基质栽培,设置5个氮素处理的营养液(50、150、250、350、450 mg·L^-1,分别设为N1~N5)、2个CO2浓度(300、600μL·L^-1,分别设为C1、C2),分别测定植株开花期、坐果期、果实膨大期生物量及叶片硝态氮和矿质元素含量。结果表明:中氮处理(N 250~350 mg·L^-1)下,植株干质量、叶片硝态氮含量以及矿质元素N、P、K、Ca、Mg含量均较高。增施CO2处理后,番茄植株干质量较C1处理增加了10.2%,叶片N、K、Mg含量都增加了20%左右,P含量没有变化,Ca含量降低了25.67%;低氮处理(N 50 mg·L^-1)下,番茄植株干质量、叶片硝态氮含量以及矿质元素N、P、K、Mg、Ca含量均较对照N3处理低。增施CO2处理后,植株的总干质量没有显著增加,其叶片硝态氮含量以及N、P、K含量也没有显著变化,而Ca含量在开花期和坐果期较C1处理分别增加了37.72%、15.45%,Mg含量在开花期较C1处理增加了43.86%;高氮处理(N 450 mg·L^-1)下,植株干质量较N3处理降低了18.03%,叶片硝态氮含量较N3处理增加了111.44%,叶片N、Ca、Mg含量与N3处理接近均较高,P、K含量较N3处理均降低了10%。增施CO2处理后,植株干质量较C1处理增加了35.92%,叶片硝态氮含量增加不显著,叶片N、K、Mg含量较C1处理分别增加了19.06%、27.82%、24.87%,而叶片P含量变化不显著,叶片钙含量在番茄开花期、坐果期和果实膨大期都较低,较C1处理分别降低了21.37%、17.16%、7.75%。综合番茄生长各项指标及经济效益,在营养液N浓度为250~350 mg·L^-1时,增施CO2浓度到600μL·L^-1(C2)最能促进开花期番茄植株叶片养分含量的增加。  相似文献   

12.
研究了在150 mmol ? L-1 NaCl胁迫下含铵态氮、硝态氮和硝酸铵(氮素浓度均为3 mmol ? L-1)的营养液培养的番茄幼苗生长、细胞超微结构、根系活力和光合作用参数的变化。结果表明:NaCl胁迫下,硝态氮处理叶片细胞出现伤害现象,而硝酸铵处理未见明显变化。铵态氮处理细胞超微结构明显发生破坏性变化,盐胁迫下,其伤害加剧。NaCl处理下,不同氮素形态处理下的植株生物量和根系活力均显著下降,其中硝酸铵处理的植株生物量和根系活力维持最高。NaCl胁迫下3种氮素形态处理的植株净光合速率(Pn)和蒸腾速率(Tr)均显著下降,其中硝酸铵处理的Pn和Tr要明显高于其他氮素处理。NaCl胁迫下,硝态氮处理和硝酸铵处理的水分利用效率(WUE)和气孔限制值(Ls)均明显上升,而铵态氮处理显著降低。综上,盐胁迫下,硝酸铵处理下番茄幼苗可维持较好的细胞超微结构、根系活力和较高的光合作用,维持较高的生物量,从而维持较高的耐盐性。  相似文献   

13.
Summary

An economic assessment was made of whether leaf vegetables can absorb almost all of a given amount of an L-ascorbic acid solution applied by soaking the roots for 12 h. The effects of storage temperature on the foliar exogenous ascorbic acid content were also observed. It was found that the given amounts of L-ascorbic acid solution are entirely absorbed by lettuce plants (Lactuca sativa L., cv. Redfire) and are over 90% absorbed by spinach (Spinacio olerácea L., cv. Read) and bunching onion plants (Allium fistulosum L., cv. Hakata Kuronegi). Due to the soaking treatment, the sum of the L-ascorbic acid (AA) and dehydro-ascorbic acid (DHA) contents (mg per 100 g fresh weight) in the leaves of plants which showed no signs of wilting increased from 38.9 to 201–221 in lettuce, from 76.5 to 196–225 in spinach and from 46.7 to 134–144 in bunching onion. The foliar AA content in all the plants stayed at approximately the same value during a storage period of 7 d at 4°C, but decreased significantly at 25°C. The foliar DHA content in all of the plants stayed at approximately the same value during storage at both 4 and 25°C. These results suggest that the ascorbic acid introduced into leaf vegetables can be used effectively by consumers when the vegetables are stored at low temperature.  相似文献   

14.
Effects of arbuscular mycorrhizal fungi (AMF) alone or in combination with bacterial consortium (AMF+BC) inoculation prior to induced salinity (NaCl @ 150 or 250 mM) were studied on root growth; plant biomass; leaf area; Na+ and K+ contents; leaf water potential (Ψw); osmotic potential (Ψπ); photosynthesis rate (Pn); and contents of chlorophyll, phytohormones, and polyamines in the grape rootstock ‘Dogridge’, popular among Indian vine growers. AMF inoculation in the NaCl untreated rootstocks plants increased root growth, root and shoot biomass, and leaf area and improved leaf Ψw, Ψπ, Pn, and chlorophyll content, and also countered the stress-induced decline in the NaCl treated plants. The abscisic acid (ABA), cytokinins, and polyamine-spermidine and spermine contents in the leaves of NaCl untreated or treated were significantly increased by the AMF inoculation. Among the treatments, AMF with BC was relatively more effective than AMF alone with respect to changes in above morpho-physiological characters. The results depicted that AMF (AMF alone or AMF+BC) inoculation significantly improved salinity tolerance of grape rootstock and tolerance is induced by improvements in plant water balance, K+:Na+ ratio, and Pn, besides distinct accumulations in ABA and polyamines-spermine and spermidine. The above findings have potential in suggesting the AMF usefulness in improving the efficacy of ‘Dogridge’ rootstock in grape cultivation under salt affected soils.  相似文献   

15.
Sweet cherry has a short post-harvest shelf life and this greatly affects the consumer preference and export of fresh fruits. In this study, the effects of pre-harvest application of a hexanal formulation (enhanced freshness formulation, EFF) and post-harvest application of hexanal vapour and 1-MCP on quality parameters and shelf life of sweet cherry were investigated. Cherries subjected to pre-harvest spray with EFF had better color, brightness and firmness than unsprayed cherries even after 30 days of storage at 4 °C. These EFF-treated cherries also showed higher chroma values indicative of enhanced red color. Post-harvest application of either, hexanal vapour, 1-MCP, or a combination of both, enhanced the firmness of cherries. These treatments also resulted in higher levels of superoxide dismutase and ascorbate peroxidase activities. The levels of anthocyanins and phenolic components were either enhanced or maintained during the 30-day storage period. Our results suggest that a pre-harvest application of EFF combined with post-harvest treatment of hexanal and 1-MCP may enhance the quality and shelf life of sweet cherry.  相似文献   

16.
Summary

The aim of this work was to assess the influence of three levels of aeration of the nutrient solution (high, low, or no aeration) on the growth and quality of two cultivars of purslane (Portulaca oleracea L.): the commercial cultivar, ‘Golden Purslane’, and a local Spanish accession, C-215. Both were grown in a floating system over four crop cycles. Our results showed purslane to be a crop that exhibited little sensitivity to oxygen depletion in the rooting medium, since it was able to adapt to a gradual reduction in oxygen content. Under such conditions, purslane plants created an aerenchyma tissue (equivalent to approx. 10% of root sections in the non-aerated treatments in both cultivars) that helped to maintain growth. Under conditions in which no aeration was provided, there was a slight decrease in plant growth. The final quality of the product was improved because leaf nitrate concentrations were reduced (by more than 1,300 mg kg–1 FW) compared with the high aeration treatment, and the content of functional phytochemicals and SPAD values (chlorophyll contents) were increased.  相似文献   

17.
Individual and combined effects of salinity and B toxicity on growth, the major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; ascorbate peroxidase, APX) activities, ascorbic acid, proline, and H2O2 accumulation, and stomatal resistance (SR), malondialdehyde (MDA), membrane permeability (MP) and the concentrations of sodium (Na), chloride (Cl) and boron (B) of lettuce were investigated. Boron toxicity and salinity reduced growth of lettuce plants. Under B toxicity, B concentration of the plants was increased, but in the presence of NaCl, the concentration of B was significantly reduced. Sodium and Cl concentrations were increased in B + NaCl and NaCl treatments. Membrane damage was more pronounced in NaCl and B + NaCl treatments. Stomatal resistance of the plants was significantly increased by salinity treatments. The accumulation of proline and ascorbic acid was the highest in the B + NaCl treatment. In general, stress conditions significantly increased H2O2 and antioxidant enzyme (SOD, CAT and APX) activities. The present results indicate that stomatal closure is an important response of lettuce against NaCl and B + NaCl stress. Furthermore NaCl and B + NaCl toxicity-induced oxidative stress in lettuce resulting in lipid peroxidation and membrane damage. Increased antioxidant enzyme activities and also accumulation of ascorbic acid and proline are involved in order to overcome B- and NaCl-induced oxidative stress.  相似文献   

18.
Summary

The effect of nitrogen availability and low level supplementary light on the growth and nitrate content of butterhead lettuce (Lactuca sativa var. capitata L.) grown in soil under greenhouse conditions in winter was studied. No significant interactions between nitrogen availability and supplementary light on yield, nitrate content, osmotic potential of expressed leaf sap and component osmotica were found. Supplementary light greatly increased plant growth and resulted in earlier harvest. When harvested with similar fresh weights, plant nitrate content was significantly reduced by supplementary light although the effect was slight. The reduced contribution of nitrate to sap osmotic potential at the higher light level was accompanied by a significant increase in the contribution of sucrose. While plant fresh weight was unaffected by the rate of nitrogen application, a positive correlation between nitrate content and nitrogen application rate was found. Reduced nitrate content at low nitrogen application rates was accompanied by increased contributions of chloride, glucose and sucrose to sap osmotic potential.  相似文献   

19.
Triacontanol (1-triacontanol) applied as a foliar spray at 10(-7) M to 4-day-old, hydroponically grown leaf lettuce (Lactuca sativa L.) seedlings in a controlled environment increased leaf fresh and dry weight 13% to 20% and root fresh and dry weight 13% to 24% 6 days after application, relative to plants sprayed with water. When applied at 8 as well as 4 days after seeding, triacontanol increased plant fresh and dry weight, leaf area, and mean relative growth rate 12% to 37%. There was no benefit of repeating application of triacontanol in terms of leaf dry weight gain.  相似文献   

20.
In a long term experiment on salt tolerance, ber (Zizyphus mauritiana Lamk.) (cv. Umran) was grown in lysimeters artificially salinized with NaCl, CaCl2, MgCl2 and MgS02. No plants survived the highest salinity of 20 dSm-1 electrical conductivity. Pruning weight and tree canopy area were reduced significantly at 5 dSm-1 but trunk diameter did not decrease until above 5 dSm-1 soil ECe. The concentration of Na, Ca, Mg and Cl in leaf tissues increased substantially with increasing salinity whereas that of K decreased. Higher salinity reduced the yield and fruit set but had no adverse effect on fruit quality. The 50% yield decrement was found to be associated with a soil ECe value of 11.30 dSm“'.  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