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1.
龙眼冷藏适温及其冷害的研究   总被引:40,自引:1,他引:39  
周云  季作梁 《园艺学报》1997,24(1):13-18
研究了广东省主栽石硖龙眼(DimocarpuslonganaLour.cv.Shixia)品种的低温贮藏、冷害及其生理生化反应,结果表明:0℃下贮藏14天果实开始表现冷害,21~28天发生不可逆冷害,果实受冷害后果皮细胞膜透性增大,呼吸作用异常升高,过氧化氢酶(CAT)与超氧化物歧化酶(SOD)活性明显降低,好果率显著下降,贮藏期缩短。在8℃下贮藏21天表现褐变与腐烂。在4℃下贮藏既不表现冷害,褐变也只在贮藏30天以后才开始表现。贮藏中乙烯释放量一直保持低水平,未出现高峰  相似文献   

2.
芒果冷害对两种自由基清除剂的影响   总被引:18,自引:1,他引:17  
王燕  李雪萍 《园艺学报》1995,22(3):235-239
紫花芒果在2℃中15天完全冷害,冷害发生时,超氧物歧化酶(SOD)活性略有上升后下降,过氧化氢酶(CAT)活性持续下降,说明冷害可降低CAT和SOD活性,加强膜脂过氧化作用。非冷害情况下,紫花芒果在10℃中贮藏20天开始启动后熟;成熟过程中,SOD和CAT活性达高峰,说明果实启动成熟时生命活动大大加强。  相似文献   

3.
间歇升温对芒果冷害及生理生化反应的影响   总被引:23,自引:3,他引:20  
张昭其  洪汉君 《园艺学报》1997,24(4):329-332
对低温贮藏中的芒果进行间歇升温处理,结果表明:间歇升温处理延迟了2℃贮藏果冷害引起的乙烯释放及呼吸强度的上升,延迟了果皮多胺水平的上升,使果皮的SOD活性维持在较高水平,细胞膜透性增加缓慢,从而显著提高了芒果的抗冷害能力。但间歇升温处理使10℃贮藏果乙烯释放高峰及呼吸高峰提前且峰高增加,果皮SOD活性降低,果皮细胞膜透性增大,从而促进了芒果的成熟衰老。  相似文献   

4.
芒果果实冷害过程中谷胱甘肽和抗坏血酸含量的变化   总被引:4,自引:0,他引:4  
季作梁  戴宏芬 《园艺学报》1998,25(4):324-328
‘紫花’芒果果实(MangiferaindicaL.ZhiHua)2℃贮藏15d时发生严重的冷害。贮藏前期,还原型谷胱甘肽(GSH)、还原型维生素C(AsA)含量略有上升,说明短期低温胁迫可促使机体提高清除氧自由基能力,以适应不良环境。随冷害时间延长,GSH、AsA含量下降;膜脂过氧化产物(MDA)、膜透性、氧化型谷胱甘肽(GSSG)和氧化型维生素C(DHA)增加,表明细胞防御能力下降,自由基代谢平衡可能被打破,膜脂过氧化加剧,果实冷害加重。10℃贮藏的芒果,无冷害症状,22d时果实启动成熟,贮藏期间GSH、AsA含量维持较高水平。  相似文献   

5.
不同贮藏温度对大五星枇杷果实保鲜效果的研究   总被引:4,自引:0,他引:4  
枇杷成熟于初夏高温多湿季节,果实生理活动旺盛,含水量多,极易腐烂变质,一般条件下难以贮存和长途运销,采后损失率高。目前,枇杷贮藏最常用的方法是冷藏法。郑永华等把枇杷果实在1℃低温贮藏,可显著抑制果实失水,贮藏期可达20天以上;Mukerjece认为,枇杷贮藏在3℃低温下能减少腐烂;周德荣通过0、5、15℃和常温比较表明,“照种”枇杷在5℃下贮藏31天的好果率最高为83.9%。但近年来,一些研究报道,枇杷果实在不适宜的低温下长期贮藏会发生冷害现象。曾雅鹃等发现,在1℃低温下贮藏,枇杷果皮难剥,果肉变硬,  相似文献   

6.
据《食品科学》2012年第4期《低温预贮对冷藏桃果实冷害及能量水平的影响》(作者赵颖颖等)报道,将桃果实在12DC预贮藏6天,后于0℃贮藏30天,每隔5天测定果实的褐变指数、硬度和出汁率等冷害指标,  相似文献   

7.
以"岵山晚荔"果实为材料,在(5±1)℃包装、25℃包装和敞开放置室内环境下贮藏,比较贮藏效果及果实内在品质变化。结果表明,(5±1)℃包装低温贮藏期间,"岵山晚荔"果肉营养成分变化小,果实呼吸作用、果皮细胞膜透性等采后生理代谢变化慢。而采用25℃包装和敞开放置室内贮藏荔枝,则导致果实衰老加速,货架寿命减短。  相似文献   

8.
茄子果实冷害生理的研究   总被引:8,自引:0,他引:8  
余挺 《园艺学报》1998,25(3):303-305
‘杭州红茄’果实在(2±1)℃低温下贮藏6d即出现冷害症状。冷害发生前乙烯释放量较高,而后急剧降至较低水平;SOD活性在此温度下前8d一直呈上升趋势,但显著低于(13±1)℃条件下的活性;CAT活性在4d后即迅速降至较低水平;膜透性和POD活性则在冷害发生(第6天)后急剧上升。表明果实冷害的发生是冷害低温抑制SOD和CAT活性、强化膜脂过氧化作用的结果,而POD活性的上升则促进了冷害的发展。  相似文献   

9.
本试验中的石榴果实呼吸比率较低,无呼吸高峰出现。根据果皮色泽、汁液色泽及成分的变化测定,它们产生的乙烯量很少,而且对各种外加乙烯处理无反应。二氧化碳和乙烯生产率随温度的增加而增长。在0和10℃间果实的呼吸商为3.4;10和20℃间为3.0;而20和30℃间则为2.3。在5℃或低于5℃下贮藏导致了果实冷害,并且冷害症状的严重程度随贮藏时间的增加温度下降(3.5℃以下)而增加。冷害症状(在果实移至20℃贮藏3天后变得愈加明显)包括果皮褐色化、表皮凹陷和对衰败组织敏感性的  相似文献   

10.
荔枝采后褐变原因及贮藏保鲜技术研究进展   总被引:3,自引:0,他引:3  
一、荔枝采后褐变的研究 荔枝成熟于高温高湿季节,果实含水量高,含糖量 高,呼吸作用特别旺盛,贮藏的营养物质消耗快,水分蒸发快,造成代谢失凋,加速果实的褐变进程,缩短贮藏寿命。另外,高温高湿的条件,很利于荔枝果实表面病原菌生长,果实容易腐烂变质,故荔枝极不耐贮运。一般情况下,荔枝果实采收后在常温下放置,如果没有适当包装,果皮在2-3d内失去诱人鲜红色并表现褐色症状。梁汉华等研究表明,在不采取任何包装情况下,贮藏3天,果皮全部褐变,商品率为0,失重率为18.21%。 许多研究结果表明,果皮褐变与果实失…  相似文献   

11.
AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β-particles emission from 188Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by 188Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [3H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of 188Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from 188 Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G0/G1 arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.  相似文献   

12.
多效唑对猕猴桃离体试管苗生长及内源激素的影响   总被引:18,自引:0,他引:18  
多效唑(PP333)处理猕猴桃试管苗,降低了其生长强度;植株体内的GA3、IAA和ZT含量下降,ABA的含量上升,乙烯释放率增加;并且能降低外源的GA3和IAA促进生长的作用,而外源的GA3和IAA又能不同程度地逆转多效唑的抑制作用,使植株恢复生长。  相似文献   

13.
AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.  相似文献   

14.
Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere.  相似文献   

15.
AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis.  相似文献   

16.
Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations, dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme temperatures (summer maximums, winter minimums). The correlation (r 2) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for 37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain the patchy distribution of many species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

17.
AIM: To detect the expression of cytoplasmic inhibitor of apoptosis protein 2 (c-IAP2) and growth arrest-specific gene 1 (GAS1) in Hodgkin's lymphoma (HL) and anaplastic large cell lymphoma (ALCL) and to investigate the role of two genes in the pathogenesis of HL and ALCL.METHODS: HE staining, the antibodies CD30, CD15, CD45RO and CD20 were used to screen the cases of HL and ALCL from 288 cases of lymphoma. The clarified HL and ALCL were subjected for immunohistochemical staining by SP and ABC methods to analyze the expression of c-IAP2 and GAS1. RESULTS: ①The positive rate of c-IAP2 in HL was 25/26(96.1%) while that in ALCL was 6/19(31.6%), there presented statistic significance between HL and ALCL groups(P<0.05), meanwhile the positive rate of GAS1 showed statistic significance between HL and ALCL groups(P<0.05). ②Two cases were showed to be a mixed type combined with large tumor cells of HL and relatively smaller tumor cells of ALCL.CONCLUSION: ①The different expression of c-IAP2 and GAS1 in HL and ALCL implied a different mechanism of oncogenesis and the different defects in the pathway of signal transduction of apoptosis in HL and ALCL;②Few cases showed an overlap and a likely transitional state between HL and ALCL; ③The different expressing manner of GAS1 and c-IAP2 in HL and ALCL implied the potential marks for the differential dignosis of two kinds of lymphoma.  相似文献   

18.
We tested whether size of habitat patches and distance between patches are sufficient to predict the distribution of the mountain vizcacha Lagidium viscacia a large, rock-dwelling rodent of the Patagonian steppe Argentina, or whether information on other patch and landscape characteristics also is required. A logistic regression model including the distance between rock crevices and depth of crevices, distance between a patch and the nearest occupied patch, and whether or not there was a river separating it from the nearest occupied patch was a better predictor of patch occupancy by mountain vizcachas than was a model based only on patch size and distance between patches. Our results indicate that a simple metapopulation analysis based on size of habitat patches and distance between patches may not provide an accurate representation of regional population dynamics if patches vary in habitat quality independently of patch size and features in the matrix alter connectivity. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

19.
20.
XU Qi  DONG Er-dan  CHEN Kai  HAN Qi-de 《园艺学报》2002,18(12):1544-1547
β3-adrenergic receptor is the third subtype of β-adrenergic receptors. The genetic structure and pharmacological property of β3-adrenergic receptor are markedly distinguished from β1-and β2-adrenergic receptor subtypes. Recently studies show that myocardial β3-adrenergic receptor mediates negative inotropic effect through Gi-protein/NO/cGMP pathway, the expression of β3-adrenergic receptor and negative inotropic effect mediated by β3-adrenergic receptor are increased in heart failure. However, because of the low expression of β3-adrenergic receptor in the heart, the actual pathophysiological significance of β3-adrenergic receptor remains unknown.  相似文献   

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