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1.
模拟酸雨条件下海泡石对污染红壤镉、铅淋溶的影响 总被引：4，自引：0，他引：4
采用填充土柱淋溶试验研究不同pH值模拟酸雨和海泡石添加量对重金属污染红壤Cd、Pb淋溶的影响.结果表明,Cd在酸雨pH值较低时累积淋溶量较大,Pb的累积淋溶量随酸雨pH值的降低逐渐增加,pH值为3.5处理的Pb总累积淋溶量显著高于其他pH值处理(高出54.9％).与对照相比,模拟酸雨pH值为3.5时,添加5 g/kg和10 g/kg海泡石处理Cd的总累积淋溶量明显增加(分别增加24.6％和26.3％),而Pb的总累积淋溶量分别显著降低34.7％和25.7％;酸雨pH值为4.5时,添加5 g/kg和10g/kg海泡石处理降低了Cd的累积淋溶量(分别降低13.0％和1.4％),而Pb的淋溶量随海泡石添加量的增加而降低,10 g/kg海泡石处理的Pb总累积淋溶量显著下降17.6％;pH值为5.5和6.5时,海泡石处理Cd累积淋溶量均有所下降,而对Pb的淋溶无显著降低效果.酸雨酸性强度的增大增加了Cd、Pb的淋溶风险,且Pb比Cd敏感.添加海泡石可有效减少酸雨对土壤中Pb的淋溶,但其对Cd淋溶的影响受酸雨酸性强度的影响. 相似文献
2.
不同颜色防雨布对杨梅生长发育及果实品质的影响 总被引：1，自引：0，他引：1
为提高杨梅综合品质及经济效益,研究延迟杨梅成熟期、降低落果率的技术措施,在杨梅硬核期和转色期分别设置覆盖防虫网及防虫网配合覆盖白、蓝、绿、红、黑色防雨布处理,以无覆盖处理为对照(CK1),测定不同处理对杨梅生长发育及果实品质的影响。结果表明,与CK1相比,绿色和蓝色防雨布有利于降低温度和相对湿度,而红色和黑色防雨布有利于温度升高,所有处理均显著抑制光合速率和枝梢的伸长,光合速率抑制率达30.62%~66.75%,其中转色期覆盖防虫网+绿色防雨布处理的抑制率最高。CK1的果实在成熟时100%脱落,硬核期和转色期进行防虫网单独覆盖和防虫网+黑色防雨布共4个处理的落果率在35.23%~70.49%之间,其他处理能显著降低杨梅果实落果率,落果率在16.44%~19.9%之间;防虫网+绿色防雨布处理、防虫网+蓝色防雨布处理延迟杨梅果实成熟时间最长,达5~9 d。综合分析杨梅果实总糖含量、维生素C含量等品质指标,转色期覆盖防虫网+蓝色防雨布处理的果实综合品质最佳,而覆盖防虫网+黑色防雨布处理的最差。本研究结果为有效利用不同颜色防雨布开展杨梅设施栽培、延迟杨梅供应期提供了理论指导。 相似文献
3.
模拟酸雨对荔枝园土壤氮素迁移和土壤酸化的影响 总被引：9，自引：3，他引：9
采用短期室内淋溶方法研究了模拟酸雨对供试荔枝果园土壤全N、碱解N、硝态N、铵态N含量变化的影响。结果表明．各处理土壤淋出液的全N、硝态N、铵态N含量随着模拟酸雨酸度的增强而依次增加，其中pH2．5酸雨淋溶处理与其它处理间的淋出液含量差异显著，而pH≥4．5酸雨淋溶处理与对照（pH6．5）间的差异大部分不显著；各处理的土壤较淋溶前其全N、NOjN（pH2．5酸雨处理例外）、NH1＋-N的含量均有增加趋势。引进土壤的实际酸化速率H＋产生值衡量供试土壤的酸化，只有pH2．5的模拟酸雨淋溶促进了土壤的酸化，而pH≥3．5的模拟酸雨处理对土壤的酸化具有一定的缓冲作用，且土壤酸度减弱。 相似文献
4.
几种低分子量有机酸淋溶对土壤铝、硅及盐基离子淋失的影响 总被引：4，自引：0，他引：4
采用50cm原状土柱进行模拟淋溶实验,比较研究了模拟酸雨和几种低分子量有机酸对红壤Al、Si及盐基离子淋失的影响。结果表明,模拟酸雨淋洗后土壤中有极少量的Al和一定量的Si及盐基离子淋出。与去离子水对照相比,pH3.5和pH4.5模拟酸雨处理Si的淋出总量分别增加了6.52%和3.26%;K 、Na 、Ca2 和Mg2 等盐基离子淋出量增加了2.41%~96.80%。100μmol/L的柠檬酸、苹果酸和草酸处理Al、Si的淋出量与模拟酸雨处理相差不大,而10mmol/L的柠檬酸、苹果酸和草酸处理则比模拟酸雨处理有显著的增加。有机酸淋洗后淋出液中各盐基离子含量均要高于模拟酸雨处理,盐基离子淋出总量是模拟酸雨处理的1.58~9.27倍。实验结果说明低分子量有机酸在酸化土壤方面比酸雨有更大的威胁。由于盐基离子的大量淋失,模拟酸雨和有机酸淋洗后淋出液pH均要高于原淋洗液pH。 相似文献
5.
本研究利用不同剂量的60Coγ射线对桃果实进行贮前辐照处理,以观察桃果实在冷藏过程中压缩特性的变化规律,并测定了果实的糖度和pH值,获得相应的品质参数。试验结果表明:1.0kGy剂量的辐照处理加速果实的后熟和软化,0.3kGy剂量的辐照处理对果实硬度Fmaxi和压缩弹性模量E没有显著的影响;辐照对pH值和失重率有一定影响,对糖度没有显著影响。在贮藏初期糖酸比下降,而在后期0.3kGy剂量的辐照使糖酸比下降平缓。 相似文献
6.
镧对西葫芦幼苗模拟酸雨胁迫的缓解效应 总被引：2，自引：0，他引：2
以西葫芦为材料, 研究了模拟酸雨胁迫下适量镧（La）对幼苗生长及叶绿素、可溶性蛋白和脯氨酸含量的影响。结果显示, 镧处理对酸雨胁迫有一定的缓解作用. 在pH 3.5和3.0 时,幼苗鲜重均显著高于模拟酸雨组,并恢复到对照的94.7%和78.6%;但在其他胁迫强度下, 镧处理的缓解效应不显著。叶绿素和可溶性蛋白的含量变化与幼苗鲜重类似,在pH 3.0时镧处理的缓解效应最显著;pH 3.5时镧处理的可溶性蛋白含量超过对照。脯氨酸含量呈现持续上升趋势,且镧处理可增加脯氨酸的积累,但只有pH 3.5和3.0 时显著高于模拟酸雨组。表明镧处理只对中强模拟酸雨胁迫有显著的缓解效应。 相似文献
7.
木麻黄幼苗渗透调节物对酸雨胁迫的响应研究 总被引：2，自引：0，他引：2
对模拟pH2 .5～4 .5酸雨胁迫3个月后木麻黄幼苗渗透调节物含量测定结果表明,pH4 .0～4 .5酸雨胁迫后木麻黄幼苗小枝可溶性糖含量显著低于对照,但(pH2 .5～3.5 )酸雨胁迫后其含量显著高于对照;与对照相比酸雨胁迫使木麻黄幼苗小枝可溶性蛋白质含量增加,游离脯氨酸和谷胱甘肽含量则极显著增加。酸雨胁迫下木麻黄幼苗具有积累较高浓度的有机渗透调节物及改善渗透调节的生理应答能力 相似文献
8.
模拟酸雨对盆栽马尾松叶片光合特性的影响 总被引：3，自引：0，他引：3
采用LI-6400XT便携式光合测定仪,对缙云山马尾松在不同强度酸雨(pH 5.6,pH 5.0,pH 4.0,pH3.5,pH 3.0,pH 2.5和pH 2.0)下的光合特性进行测定。结果表明:pH 3.5～5.6的酸雨处理条件下,净光合速率、蒸腾速率和气孔导度受酸雨影响不明显,从pH 3.0或pH 2.5开始出现明显的降低趋势,且pH2.0出现不同于前几种处理的日变化趋势;从水分利用效率分析,酸雨胁迫对其影响不明显;pH 4.0～5.6的酸雨处理条件下,最大净光合速率、光饱和点和光补偿点变化不明显,从pH 3.5开始出现显著降低的趋势,且在pH 2.0时受酸雨影响已经非常明显,无法模拟出最大净光合速率、光饱和点和光补偿点;总体分析,酸雨对马尾松叶片光合特性的影响临界范围为pH 3.5～4.0,酸雨对马尾松幼苗致命的影响临界范围为pH 2.0～2.5。 相似文献
9.
酸雨对白术土壤微生物及酶活性的影响 总被引：6，自引：0，他引：6
用不同pH值(2.5,3.5,4.5,5)的模拟酸雨处理白术植株及其土壤,测定模拟酸雨对土壤中微生物数量以及土壤酶活性的影响。结果表明,各处理pH的模拟酸雨能导致土壤中细菌、放线菌和真菌的比例发生变化,微生物总数随模拟酸雨pH的降低而不断减少;模拟酸雨能抑制氮素生理群细菌的生长和繁殖;当酸雨pH=5时促进纤维素分解菌的生长,但pH值过低时却有明显的抑制作用;模拟酸雨对脱氢酶、过氧化氢酶、脲酶和蛋白酶的活性有明显的抑制作用,对磷酸酶活性却有一定的促进作用。 相似文献
10.
模拟酸雨对施肥条件下赤红壤氮磷淋失特征的影响 总被引：3，自引：0，他引：3
通过土柱模拟淋洗试验,研究了施用等量有机复合肥条件下,不同酸度模拟酸雨对赤红壤氮磷淋失特征的影响。结果表明,铵态氮、硝态氮、无机氮和总氮淋失量均随酸雨pH值增大而下降;pH 2.0模拟酸雨和对照(pH 6.5)的无机氮和总氮淋失量差异不显著,但均显著高于pH 3.0、pH 4.0和pH 5.0酸雨;pH 5.0模拟酸雨无机氮和总氮淋失量均最低,表明强酸性酸雨和中性淋洗液均促进氮淋失,而酸度与土壤接近的酸雨减少氮淋失。与对照相比,模拟酸雨对DP淋失无显著影响,但显著降低PP和TP淋失;不同模拟酸雨各形态磷淋失量均无显著差异,表明酸雨对赤红壤磷淋失影响有限。酸雨对淋滤液氮磷浓度动态变化和氮磷累计淋失量动态变化等均无显著影响。 相似文献
11.
The first objective of this study was to search for a possible correlation between accumulation of calcium (Ca), potassium (K), and magnesium (Mg) and fruit transpiration in developing apricot (Prunus armeniaca L.) fruit. Secondly, the work aimed to determine the significance of transpirational flux on Ca nutrition. We hypothesized that if the fruit transpiration is the determining factor of Ca accumulation (phloem‐immobile element) then the import of Ca would be suppressed by restriction of fruit water loss, while the import of phloem‐mobile nutrients (i.e., K and Mg) would not be. To test this hypothesis, the seasonal changes of transpiration and of Ca, K, and Mg concentration/accumulation were assessed in fruits left to naturally transpire or under restricted transpiration (bagged fruits). Fruit transpiration was measured on detached fruits using a portable gas‐exchange equipment (ADC‐LCA4, ADC BioScientific Ltd, Hoddesdon, England). Results demonstrated that 83% of total fruit Ca content was gained within the first 4 weeks after fruit‐set, and that Ca import ceased concomitantly to a reduction of transpiration. In spite of the limitation of fruit transpiration, Ca entered the nontranspiring fruits, and its concentration was about 45% of that in control fruits suggesting that other factor(s) operated for Ca accumulation. This study provides the evidence that fruit transpiration accounted for 55% of total Ca that entered a fruit. We conclude that optimal soil Ca availability and apportioning to the fruit during the early 4 weeks of growth are essential to sustain the fruit demand of this nutrient and that some cultural practices (e.g., summer pruning, irrigation) should be tested as possible tools to improve fruit Ca nutrition via increasing fruit transpiration. 相似文献
12.
The total phenolic content of 13 commercially available fruit juices and juice drinks, selected to represent the most popular juice flavors in the United Kingdom, were analyzed using the Folin-Ciocalteu assay. Individual phenolic compounds were identified and quantified using HPLC-PDA-MS2. The catechin content and degree of polymerization of proanthocyanidins were also analyzed. Purple grape juice contained the largest number of individual phenolic compounds and also the highest concentration of total phenolics. The main components were flavan-3-ols, anthocyanins, and hydroxycinnamates, which accounted for 93% of the total phenolic content. In contrast, white grape juice, which contained principally hydroxycinnamates, had the lowest total phenolic content. Antioxidant activity was measured using the ORAC and FRAP assays, and the data obtained were in broad agreement with total phenol content. In view of the recent findings of the Kame project indicating that long-term fruit juice consumption can provide protection against Alzheimer's disease (Dai et al. Am. J. Med. 2006, 379, 464-475), it is suggested that the protective effects may be enhanced by consumption of a combination of juices rich in phenolics and containing a diverse variety of individual phenolic compounds, namely, juices derived from purple grapes, grapefruit, cranberries, and apples. 相似文献
13.
Watermelon (Citrullus lunatus Thunb.) plants cv ‘Sugar Baby’ were grown hydroponically in a greenhouse under NO3:NH4 ratios of 3:1, 1:1, and 1:3. Plants receiving the high ammonium treatment expressed symptoms of NH4‐toxicity and declined rapidly after bloom. Reducing NO3:NH4 from 3:1 to 1:1 significantly reduced growth, water use, fruit yield, flesh soluble solids and uptake of NO3, NH4, K, Ca and Mg. 相似文献
14.
Mamoru Sato Daisuke Takata Keitaro Tanoi Tsutomu Ohtsuki Yasuyuki Muramatsu 《Soil Science and Plant Nutrition》2013,59(1):156-164
Following the accident at the Tokyo Electric Power Company, Fukushima Daiichi Nuclear Power Plant (FDNPP), radiocesium (134Cs + 137Cs) concentrations in deciduous mature fruits were determined in orchards in the northern area of Fukushima Prefecture. At the time of the nuclear accident, most deciduous fruit trees were in the dormant stage prior to bud burst. To evaluate the relationship between radiocesium deposition in the soil and fruit contamination, radiocesium concentrations were measured from the 5-cm topsoil and from six fruit species across 17 orchards in 2011. The vertical distribution of radiocesium in the topsoil (0–30 cm in depth) and its spatial distribution in the 5-cm topsoil underlying the tree canopy of a peach, Prunus persica (L.) Batsh, orchard (“Akatsuki” cultivar) were also investigated. Significant correlations between the radiocesium concentration in the mature fruit and that in the 5-cm topsoil layer were observed for the 17 orchards as well as for the trees of the peach orchard. However, 93% of the 137Cs found in the 30-cm soil core was retained within the top 3 cm of the soil in the peach orchard. Considering the profile of the root of this deciduous fruit tree, we assumed a negligible level of radiocesium uptake via the roots. However, the possibility of inward migration via the bark was undeniable, because some radiocesium adhered to the tree canopy before bud burst while depositing on the soil surface. Additionally, transfer factors for peach and grape, hybrid of Vitis labrusca L. and Vitis vinifera L., from young, uncontaminated trees cultivated with contaminated soil were lower than those previously reported. 相似文献
15.
The responses of fruit antioxidants in two strawberry cultivars differing in their sensitivity to NaCl stress were studied. The sensitive cv. Elsanta and the less sensitive cv. Korona were treated with NaCl solutions of 40 and 80 mmol/L in the nutrient solution. In general, moderate salinity resulted in increases of antioxidant capacity. In cv. Korona, salt stress increased the activity of superoxide dismutase and the contents of glutathione, phenols, and anthocyanins, while that of ascorbic acid decreased. In cv. Elsanta, changes of superoxid dismutase activity and of ascorbic acid concentration were comparable to those of cv. Korona, but the decrease of ascorbic acid was more distinct. The contents of anthocyanins decreased, and those of phenols remained similar. The glutathione content was reduced at the highest NaCl level. The results indicate that less salt-sensitive strawberry cultivars may be grown under moderate salinity stress to optimize fruit quality. 相似文献
16.
果实采前套袋对龙眼果实品质和耐贮性的影响 总被引：10，自引：2，他引：10
以福建省主栽龙眼品种“福眼”果实为材料，研究果实采前套袋对龙眼果实品质和采后耐贮性的影响。结果表明：果实采前套袋可明显改善龙眼果实的外观品质；但降低了果肉可溶性固形物、可滴定酸、维生素C和总糖等营养物质含量，导致龙眼果实甜度下降、风味变淡。果实采前套袋降低了与龙眼果皮褐变密切相关的酚类物质(包括花色素苷、类黄酮和总酚)含量和多酚氧化酶、过氧化物酶的活性，减少了龙眼果实在贮藏期间果皮褐变的发生；同时，果实采前套袋明显减轻由采前病原菌潜伏侵染所致的采后龙眼果实病害，提高果实耐贮性，延长果实贮藏期。 相似文献
17.
18.
Kari Louise Hovland Lars Sekse 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(2):91-96
A modified potometer consisting of a water-filled glass tube mounted in parallel with a metric scale and connected to a fruit was used to study water uptake into detached fruits of sweet cherry. Results describing quantities of imported water from some introductory studies were in the same range as in previously published studies conducted with alternative methods. Water uptake was measured in fruits of four cultivars kept in air of approximately 50±5% RH followed by immersion in water 1–2 h into the experimental period. This caused a significant decrease in water uptake. However, the fruits continued to accumulate water at a reduced rate. When the fruits were dried, the water uptake immediately increased to the same level as before the immersion in water. The fruit skin of two cultivars was exposed to normal air after being ruptured with four shallow cuts to simulate cuticular fractures or shallow cracks. These two treatments did not give statistically different water uptake through the pedicel, although there was a tendency to an increased rate of water uptake in fruits with ruptured fruit skin. 相似文献
19.
水果套袋技术可以减少水果的农药残留，提高果品品质，是生产无公害水果的重要手段之一。人工套袋劳动强度大、危险性高。该文根据人工套袋的步骤，自主开发了自动化套袋装置。整个装置分为：果袋自动撑开机构和套袋机构，该文主要介绍果袋自动撑开机构。包括果袋分开机构、果袋撑开机构和撑好果袋的输送机构，采用单片机控制，用气力驱动，采用两个转动块和一对真空吸盘将成叠的果袋逐个分开；采用弧形手指，将果袋的内腔撑开到最大容积，满足水果套袋的要求，实现了果袋撑开过程的自动化，作业速度达到3个/min，为套袋作业做好了准备。 相似文献
