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1.
冯彤  庞杰  于新 《农业工程学报》2004,20(Z1):175-177
实验以海洋皇马铃型银杏种子(Ginkgo biloba L)为研究对象,研究了饱和石灰水浸泡法、乙烯利浸泡法、焦亚硫酸钠浸泡法、施保功浸泡法及自然浸泡法等常见的银杏种子浸泡去皮(外种皮)方法对银杏种子贮藏效果及贮藏生理的影响对贮藏期间银杏种子呼吸强度、细胞膜透性、α-淀粉酶活性、β-淀粉酶活性、浮水率、硬化率、霉变率及失重率等指标进行了测定.结果表明焦亚硫酸钠浸泡法为合适的银杏浸泡去皮方法.  相似文献   

2.
采前激素处理对银杏种子的脱皮与保鲜效果的研究   总被引:6,自引:1,他引:5  
冯彤  庞杰  于新 《农业工程学报》2005,21(1):146-151
研究了乙烯利20、100、500 mg/L;891植物促长素20、100、500 mg/L;脱落酸20、100、500 mg/L等9种不同采前激素催熟处理方法对银杏种子采后脱皮及贮藏保鲜的影响。其中,乙烯利500 mg/L处理,采后4 d呼吸高峰到来,第6 d果肉软化,容易去皮,且贮藏90 d,除霉变率稍高外,浮水率、失水率、硬化率都较低,还原糖、蛋白质、脂肪、淀粉、蛋白质含量保持较高水平,适宜于以食用为目的的贮藏。891植物促长素500 mg/L处理发芽率高,β-淀粉酶、过氧化氢酶(CAT)、脂肪酶、多  相似文献   

3.
哈密瓜常温保鲜贮运技术研究   总被引:5,自引:3,他引:5  
该研究旨在解决新疆哈密瓜采后低温贮运费用高,常温贮运腐烂率高,损失严重的问题。针对哈密瓜采后腐烂的主要病原菌匍枝根霉(R.stolonifer)、链格孢霉(A.Alternata)、半裸镰刀菌(F.semitectum)、脂状青霉(P.digitatum),筛选出对症的抑菌剂,并研究其最适使用浓度;以常温贮藏哈密的瓜失重率、呼吸强度、过氧化氢酶(CAT)、纤维素酶、果胶甲酯酶(PE)、多聚半乳糖醛酸酶(PG)活性等为指标,研究云南虫胶作为被膜对哈密瓜采后生理的影响及其最适使用浓度。含有0.60g/L扑海因、0.8g/L氯硝胺、0.6g/L特克多、0.8g/L施宝功和1∶24(V.V-1)虫胶的混合溶液浸泡哈密瓜10s,于28℃,85%RH,贮藏30d,腐烂率1.87%,同期对照腐烂率49.54%。处理后的哈密瓜在室外温度28~34℃、棚车内温度30~38℃的条件下,经过12~15d由新疆哈密运抵苏州、上海、广州的腐烂率分别为3.37%、4.12%和4.86%。哈密瓜表皮以内0.8cm几乎无抑菌剂残留。用上述配方的虫胶与抑菌剂的混合溶液浸泡哈密瓜,可有效降低哈密瓜采后常温贮运中的腐烂率,保持良好风味和商品质量,大量节省运输费用  相似文献   

4.
锥栗贮藏过程维生素C的降解速率以及保鲜条件研究   总被引:3,自引:1,他引:3  
采用试验研究了锥栗贮藏过程中维生素C(维生素C)的降解速率及其保鲜条件。将3个不同品种的锥栗经不同浓度的抑霉唑浸泡,并在3个不同温度(-1~0℃、5℃、10℃)中进行贮藏,测定贮藏中锥栗维生素C的含量的变化。锥栗中维生素C的降解速率与维生素C的浓度成正比,求得降解速率系数k,对其进行非线性拟合,并用极差分析法和方差分析法进行分析研究。试验结果表明,最优的保鲜条件为:温度-1~0℃、品种为长芒、抑霉唑浓度2000 μL/L。  相似文献   

5.
银杏种子辐照效应及其保鲜的初步研究   总被引:8,自引:1,他引:7  
不同剂量^60Coγ射线处理去外种皮的银杏种子,50Gy以上剂量处理的种子不能发芽,种胚活力迅速下降而趋于死亡,800Gy以下剂量处理后,胚乳仍保持较长时期的活力。2000Gy以上剂量使种子失水加快,胚乳失活且变软腐烂,共电导率迅速上升,辐照处理使银杏降种子的呼吸受到较大抑制,有利于贮藏保鲜,银杏种子密封包装后,经50-200Gy辐照工在室内常温存放,含水量40.25%的银杏种子的保质期为2-3个月,当种子含水量降至35.96%时,保持期可达4-6个月。  相似文献   

6.
壳聚糖和抗坏血酸复合处理提高台湾青枣采后保鲜效果   总被引:2,自引:0,他引:2  
为了延长台湾青枣(Ziziphus mauritiana Lam.)的采后保鲜时间,基于抗坏血酸(ascorbic acid,As A)可提高果实抗氧化能力,壳聚糖涂膜处理能防止果实失水和微生物侵染,该文探讨抗坏血酸、壳聚糖涂膜及抗坏血酸和壳聚糖复合处理对台湾青枣(Ziziphus mauritiana Lam.)采后保鲜效果的影响.果实采收后当天,分别用30.0mmol/L抗坏血酸浸泡处理、8g/L壳聚糖涂膜以及30.0mmol/L抗坏血酸浸泡后并用8g/L壳聚糖涂膜复合处理,以双蒸水浸泡处理为对照,处理结束后,置于(25±1)℃和90%~95%相对湿度下贮藏,定期测定果实相关生理参数,扫描电镜观察果皮果实组织结构.结果表明,与对照相比,抗坏血酸或壳聚糖单独处理虽然对台湾青枣保鲜有一定效果,但复合处理后保鲜效果更好.表现为显著减少果实失水率和相对电导率(P<0.05),抑制果皮叶绿素降解及果实果胶酶和多聚半乳糖醛酸酶活性增加,降低原果胶分解成可溶性果胶的速率(P<0.05),使果实硬度和细胞完整性得以维持;延缓果实超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性下降,降低膜脂氧化速率,果实过氧化氢和膜脂过氧化产物丙二醛含量显著下降(P<0.05);维持果实较高的可溶性固形物(total soluble solids,SS)、可溶性总糖(total soluble sugar,TSS)、可滴定酸(titratable acidity,TA)、谷胱甘肽(glutathione,GSH)及抗坏血酸含量.研究结果说明,抗坏血酸和壳聚糖复合处理可提高台湾青枣贮藏过程中的抗氧化能力,降低氧化伤害;降低果实失水率,减缓果皮叶绿素降解速率,延缓细胞降解和软化速率,维持果实细胞完整性,降低果实的腐烂率,从而达到延长采后果实保鲜的效果.  相似文献   

7.
对柴胡种子进行自来水浸种、沙藏处理及6-BA、赤霉素、H2O2和KMnO4药剂处理试验,以研究不同处理对柴胡种子发芽率的影响。结果表明,柴胡种子经自来水浸泡,随浸泡时间的延长,发芽率升高。H2O2、6-BA、沙藏对柴胡种子发芽有抑制作用,适宜浓度的KMnO4和赤霉素对柴胡种子发芽有促进作用。加热100 ℃ 60 mg/L赤霉素浸泡24 h的柴胡种子发芽率高于其他处理,发芽率达32.00%;用自来水浸泡48 h次之,发芽率为30.00%;用6-BA处理过的柴胡种子未见发芽。  相似文献   

8.
用不同浓度的脱落酸(ABA)溶液浸泡白菜型冬油菜陇油6号种子后进行发芽试验,统计种子萌发情况,分析幼苗相关生理指标的变化。结果表明,较低浓度(10~70 mg/L)的脱落酸溶液处理有利于种子的萌发,有效提高种子发芽率、发芽势及发芽指数,提高丙二醛和脯氨酸含量,增强幼苗中过氧化物酶(POD)活性,超氧化物歧化酶(SOD)、过氧化氢酶(CAT),减缓叶绿素含量的下降,其中以30 mg/L脱落酸效果最佳。较高浓度的脱落酸溶液抑制冬油菜种子的萌发。  相似文献   

9.
红梗叶甜菜种子发芽特性的研究   总被引:1,自引:0,他引:1  
研究了不同处理条件下红梗叶甜菜种子的发芽特性。结果表明,用一定浓度的双氧水、硼酸、磷酸二氢钾浸种处理红梗叶甜菜种子,可提高种子的发芽率、发芽势和发芽指数,其中以浓度10g/L H2O2、0.5g/L H3BO3和5g/L KH2PO4处理较为适宜;赤霉素处理种子的发芽效果不明显;吸湿一回干处理对红梗叶甜菜种子发芽有良好的促进作用;红梗叶甜菜种球色泽、粒径大小与发芽的关系密切,黄色或黄褐色种球的发芽力显著高于黑色或褐色种球的,大、中粒种子的发芽力显著高于小粒种子的;叶甜菜种子不耐贮藏,发芽力下降较快,使用年限仅为1a。  相似文献   

10.
多效唑对花生种子萌发及植株生长的影响   总被引:3,自引:0,他引:3  
以不同浓度的多效唑,对花生种子进行浸种处理和盛花期叶面喷施,观测种子萌发、幼苗生长情况和植株农艺性状,收获时进行产量测定。结果表明:(1)多效唑浸种延缓花生种子萌发,使发芽率有所下降,矮化植株;(2)盛花期喷施适宜浓度的多效唑能抑制花生地上部分的生长,促进其横向生长,使主茎和分枝比对照的短,分枝数、单株结荚数、饱果率和产量均比对照的高,其中以喷施150mg/L多效唑的处理产量最高,达3806.3kg/hm^2,比对照增产12.60%。  相似文献   

11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响   总被引:2,自引:2,他引:0  
【目的】以富士(Fuji)、 秦冠(Qinguan)嫁接在平邑甜茶(Malus hupehensis Rehd.)上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水(ZZ)、 低氮正常水(DZ)、 正常氮干旱(ZG)、 低氮干旱(DG)。氮素和水分均设置两个水平,分别为正常氮(6 mmol/L NO-3-N)、 低氮(0.3 mmol/LNO-3-N)、 正常供水(保持盆中砂子相对含水量为饱和含水量的80%~85%)、 干旱处理(保持盆中砂子相对含水量为饱和含水量的60%~65%)。【结果】富士和秦冠的生物量(茎和叶)、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG),并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG); 氮、 钾元素含量在植株各部位的分布顺序依次是叶>根>茎,磷元素则是根>叶>茎;光合氮素利用效率(PNUE)和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水(DZ)处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱(DG)处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。  相似文献   

12.
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.  相似文献   

13.
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,  相似文献   

14.
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.  相似文献   

15.
“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.  相似文献   

16.
Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.  相似文献   

17.
Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.  相似文献   

18.
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.  相似文献   

19.
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.  相似文献   

20.
To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.  相似文献   

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