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1.
施加外源乙烯时机对MA贮藏桃果实品质的影响   总被引:1,自引:2,他引:1  
为了改善桃果实低温贮藏期间品质降低情况,探讨了大久保桃果实在低温条件下自发气调(MA)贮藏期间,不同时间(0、15和30 d)加入外源乙烯处理(50~80 μL/L)的效果,测定在贮藏期间及20℃下回温3 d后果实的硬度、可溶性固形物含量(SSC)、腐烂指数、可滴定酸(TA)、总糖、维生素C(Vc)的含量。结果表明,在0℃下MA贮藏15、30 d加入外源乙烯处理能较好地保持果实的质地、可溶性固形物含量,降低桃果实的腐烂率。同时15 d时加入外源乙烯处理还能较好地保持总糖和Vc含量,但对可滴定酸的影响与其他MA处理差异不显著。研究表明,MA贮藏大久保桃果实在第15天进行外源乙烯处理效果最好。  相似文献   

2.
不同气体成分贮藏对大久保桃果实品质的影响   总被引:13,自引:5,他引:13  
该文研究了大久保桃在不同气体成分下贮藏60 d以及出库后在20℃下货架期3 d后果实硬度、褐变指数、可溶性固形物含量、pH值、膜透性、出汁率和感官品质的变化。结果表明,1%的O2对桃果实产生伤害,表现为表面色泽非正常变化、桃固有风味丧失并产生严重异味;(5~10)%O2、(5~10)%CO2气体成分能够在60 d的贮藏期内保持桃果实的品质,尤其是10%O2+10%CO2处理较好地保持了果实的风味、质地和色泽,出库后果肉不褐变。与冷藏对照相比,气调贮藏能有效地延缓果实软化,抑制pH值和出汁率的升高,但对可溶性固形物的影响不大;在相同O2浓度下,随CO2浓度升高(<10%),果实在货架期期间的软化程度、褐变指数下降幅度、pH值上升程度和膜透性增加幅度均增大,表明果实能够进行正常后熟。本研究推荐的大久保桃果实气调贮藏的适宜气体指标是10%O2+10%CO2。  相似文献   

3.
西洋梨气调贮藏不同时间后货架期品质变化   总被引:3,自引:1,他引:2  
为研究西洋梨不同气调贮藏时间出库后货架期品质的变化,将西洋梨品种“阿巴特”在1.8%±0.2% O2,0.8%±0.2% CO2气体体积分数条件下进行不同时间贮藏。结果表明,与冷藏相比,贮藏期内气调贮藏可显著地抑制西洋梨果实硬度的下降和色泽的变化,降低果实出汁率、淀粉含量和乙烯释放量,并推迟乙烯高峰的出现时间,抑制淀粉酶活性的上升;货架期间,不同贮藏期出库果实自货架6 d起气调贮藏与对照相比果实硬度和淀粉含量的下降速率和色泽变化较快,果实的出汁率和淀粉酶活性明显上升,同时果实的乙烯释放明显加快。气调贮藏与对照相比可在一定程度上抑制贮藏期果实品质的下降,其中气调贮藏90 d、货架8 d的西洋梨果实能获得较好的后熟效果。  相似文献   

4.
冷锻炼处理减轻低温贮藏桃果实冷害的能量代谢机理   总被引:4,自引:1,他引:4  
为探讨通过维持低温贮藏桃果实能量代谢水平而减轻冷害的有效方法,以‘大久保’桃为试材,分别以24、5、0℃贮藏为对照,研究冷锻炼处理(8℃冷锻炼5d后转入0℃冷藏,CAT)对维持冷藏及其货架期间桃果实线粒体呼吸代谢相关酶及三磷酸腺苷(ATP)含量的影响。结果表明:24℃贮藏模式下桃果实的H+-ATPase、Ca2+-ATPase、琥珀酸脱氢酶(SDH)和细胞色素氧化酶(CCO)活性在贮藏过程中2~3d出现了活性高峰,之后随着果实的软化衰老而显著下降。5℃贮藏桃果实贮藏期间的H+-ATPase、Ca2+-ATPase、SDH、CCO活性和ATP含量最低,且下降速度也最快;0℃贮藏次之,而CAT贮藏可有效抑制桃果实H+-ATPase、SDH和CCO活性的下降,保持较高的ATP含量。随着贮藏时间的延长,货架期期间H+-ATPase、Ca2+-ATPase、SDH、CCO活性和ATP含量均降低,但CAT处理明显高于5、0℃冷藏处理。这表明冷锻炼处理可通过调节线粒体呼吸代谢酶活性,维持果实较高的能量水平,有利于减轻果实冷害的发生并延长贮藏期。  相似文献   

5.
桃的“冰温”贮藏研究   总被引:40,自引:1,他引:40  
利用“冰温”贮藏技术可以明显抑制桃的呼吸作用,推迟桃的呼吸高峰期,减少各种营养成分的损失。在此基础上,结合塑料薄膜小包装的气调性,改善了包装内的气体组成,提高了果实周围相对湿度,从而更有效地抑制了桃在贮藏过程中糖分、Vc以及水分的耗损,减少了果实腐烂率和褐变率,并保持一定的感观指标,可最大限度延长桃的贮藏时间。  相似文献   

6.
以西洋梨品种‘阿巴特’为试材,在(1.8±0.2)% O2,(0.8±0.2)% CO2气体浓度条件下,研究西洋梨不同气调贮藏时间出库货架品质的变化。结果表明,贮藏期内气调贮藏可显著地抑制西洋梨果实硬度的下降和色泽的变化,降低果实出汁率、淀粉含量、乙烯释放量,并推迟乙烯高峰的出现时间,抑制淀粉酶活性的上升;货架期间,不同贮藏期出库果实自货架6d起气调贮藏与对照相比果实硬度和淀粉含量的下降速率和色泽变化较快,果实的出汁率和淀粉酶活性明显上升,同时果实的乙烯释放明显加快。气调贮藏与对照相比可在一定程度上抑制贮藏期果实品质的下降,保持长期贮藏果实的后熟能力,提高西洋梨果实货架期品质。  相似文献   

7.
辐照处理在农产品检疫除害、杀菌保鲜方面具有重要意义。以智利进口甜樱桃为对象,研究了电子加速器辐照处理对果实花青素、色泽及保鲜效果的影响。甜樱桃经过0.00、0.41、1.06、1.88 kGy剂量电子束辐照处理后分别于室温(13~17℃)贮藏7 d、低温(4±1℃)下储藏15 d。结果表明,电子束处理对果实花青素含量的影响与贮藏温度和剂量有关,0.41kGy电子束处理的总花青素和单体花青素含量高于对照和其它剂量电子束处理。电子束处理可影响花青素的聚合和降解,4℃贮藏15 d时,电子束处理花青素聚合色素比均小于对照。硬度下降是甜樱桃贮藏的主要问题,适宜剂量电子束处理结合低温贮藏可减缓果实硬度的下降幅度。电子束辐照对甜樱桃的色泽、总可溶性固形物含量影响不大,其果实的失重率和霉变率均低于未辐照果实,保鲜效果良好。  相似文献   

8.
低温预贮处理对冷藏水蜜桃冷害和品质的影响   总被引:6,自引:2,他引:4  
为探索低温预贮处理减轻水蜜桃果实冷藏冷害的作用及适宜条件,研究了不同温度与时间组合的预贮模式对霞晖5号桃果实冷害和品质的影响。该研究先将果实置于4、8、12℃下分别预贮2、4、6、8和10 d,然后转入0℃冷藏28 d,冷藏结束后移至20℃货架贮藏3 d。货架期结束后进行果实质地多面分析和品质感官评定,并测定果实颜色、可溶性固型物、可滴定酸、褐变指数和出汁率等品质和冷害指标。结果表明,采后直接在0℃下冷藏28 d的果实出现了明显的冷害症状,主要表现为果实质地絮败和果肉发生褐变。4℃预贮果实出现严重的木质化冷害症状,8℃预贮果实褐变严重,而采用12℃、6 d预贮可最显著地减轻果实质地絮败和果肉褐变等冷害症状的发生,保持较好的感官品质。这些结果表明,12℃、6 d预贮处理在桃果实贮藏中具有较好的应用前景。  相似文献   

9.
高压静电场处理对红元帅苹果采后品质的影响   总被引:1,自引:0,他引:1  
该研究利用自制的高压静电场保鲜实验台产生的-50 kV/m和-100 kV/m高压静电场处理红元帅苹果,贮藏过程中每4d测定1次果实呼吸强度、内源乙烯释放量、果实硬度和可溶性固形物含量变化,并在贮藏结束时,对果实品质进行感官评定。实验结果表明:高压静电场处理使红元帅苹果的乙烯释放高峰推迟4 d,乙烯释放高峰值显著低于对照,并且使果实呼吸跃变推迟8 d。高压静电场处理苹果,在20℃条件下贮藏24 d,果实硬度和可溶性固形物含量显著高于对照,果实新鲜程度、脆性、硬度、粉性、甜味和苹果味等感官指标显著比对照好(p<0.01),表明高压静电场处理对保持红元帅苹果的采后品质具有显著作用。  相似文献   

10.
高氧处理对草莓采后腐烂和品质的影响   总被引:17,自引:8,他引:17  
为探索高氧处理对草莓防腐保鲜的效果,该试验研究了40%、60%、80%和100% O2及空气气流连续处理对“丰香”草莓在5℃、16 d贮藏期间果实腐烂和主要品质指标变化的影响。结果表明,高氧处理对果实总酸、可溶性固形物含量及果实表面色泽无明显影响。但60%~100%高氧处理可显著抑制草莓果实贮藏期间的腐烂,且O2浓度越高,果实腐烂率越低,以100% O2处理对果实防腐的作用最大。60%~100%高氧处理还可显著抑制果实失重,保持较高的果肉硬度和维生素C含量。40% O2处理对草莓果实腐烂无显著影响。这些结果表明,高氧处理在草莓果实采后防腐保鲜中具潜在的应用前景。  相似文献   

11.
【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.
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   

16.
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   

17.
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   

18.
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.  相似文献   

19.
Three slow-growing legume trees used for desert reforestation and urban gardening in the Sonoran Desert of Northwestern Mexico and the Southwestern USA were evaluated whether their growth can be promoted by inoculation with plant growth-promoting bacteria (Azospirillum brasilense and Bacillus pumilus), unidentified arbuscular mycorrhizal (AM) fungi (mainly Glomus sp.), and supplementation with common compost under regular screenhouse cultivation common to these trees in nurseries. Mesquite amargo (Prosopis articulata) and yellow palo verde (Parkinsonia microphylla) had different positive responses to several of the parameters tested while blue palo verde (Parkinsonia florida) did not respond. Survival of all tree species was over 80% and survival of mesquite was almost 100% after 10 months of cultivation. Inoculation with growth-promoting microorganisms induced significant effects on the leaf gas exchange of these trees, measured as transpiration and diffusive resistance, when these trees were cultivated without water restrictions.  相似文献   

20.
Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene. This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots. Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production or the positive response of the plants towards A. brasilense Cd inoculation.  相似文献   

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