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1.
渗透胁近下小麦的膜损伤与ABA增高的关系   总被引:2,自引:0,他引:2  
以渗透势为-0.67MPa的PEG根际处理小麦幼苗,在24h胁迫期间,叶片相对含水量(RWC)和叶绿素含量下降,质膜透性于18g迅速升高,丙二醛(MDA)含量在12h后急剧增加,超氧化物歧化酶(SOD)活性下降,过氧化物酶(POD)活性升高;而ABA含量在胁迫处理下的3h和15h出现两个高峰。表明渗透胁迫下ABA的积累在膜损伤之前。  相似文献   

2.
渗透胁迫下小麦的膜损伤与ABA增高的关系   总被引:5,自引:0,他引:5  
以渗透势为-0.67MPa的PEG根际处理小麦幼苗,在24h胁迫期间,叶片相对含水量(RWC)和叶绿素含量下降,质膜透性于18h迅速升高,丙二醛(MDA)含量在12h后急剧增加,超氧化物歧化酶(SOD)活性下降,过氧化物酶(POD)活性升高;而ABA含量在胁迫处理下的3h和15h出现两个高峰.表明渗透胁迫下ABA的积累在膜损伤之前.  相似文献   

3.
海仙花开花和衰老过程与膜脂过氧化   总被引:1,自引:1,他引:0  
海仙花从大蕾发育至玫红花时,开花时间较长,此后即迅速衰老萎蔫.开花和衰老过程中呼吸速率出现两次高峰,花盛开为乳白花时出现第1个呼吸峰,玫红花时又出现一次较低的呼吸峰.从大蕾发育至粉红花时,SOD和CAT活性逐渐增高,Vit.C含量逐渐降低但保持较高水平,而O-2含量低且变化不大;粉红花后,SOD和CAT活性继续升高,Vit.C含量迅速降低,O-2含量较快升高;玫红花后,SOD活性迅速降低,Vit.C含量达最低,O-2含量则迅速升高.开花前期花内MDA含量低且变化不大,相对透性值缓慢升高,粉红花后,O-2引发膜脂过氧化加强致使MDA含量和相对透性迅速升高,花萎蔫时达最高  相似文献   

4.
不同方式的水分胁迫对小麦幼苗生理的影响   总被引:4,自引:0,他引:4  
以抗旱性不同的两个冬小麦品种为材料,研究了其幼苗在PEG模拟的不同水分胁迫条件下,几个生理指标的变化,结果表明:在慢速水分胁迫条件下,抗旱性强的品种,初期叶片RWC下降幅度很少,质膜相对透性、脂质过氧化水平均略低于对照,SOD活性增加较多,抗旱性弱的品种其RWC下降幅度较大,质膜相对透性,脂质过氧化水平均高于对照,SOD活性增加较少,且抗旱性强的品种SOD对水分亏缺敏感,随着胁迫强度的增加,伴随叶  相似文献   

5.
人工老化大豆种子膜脂质的过氧化研究   总被引:3,自引:0,他引:3  
在人工老化条件下,随着劣变加剧,大豆种子的膜透性增加,脂质过氧化产物MDA含量升高,H2O2和O^-2浓度升高,而SOD和CAT活性则明显下降,由此可以认为,在人工老化过程中,大豆种子内H2O2和O^-2的消除系统产生障碍,H2O2和O^-2积累,造成膜脂质的过氧化作用加剧。  相似文献   

6.
盐胁迫对梭梭幼苗体内保护酶系统活性的影响   总被引:14,自引:0,他引:14  
分别用0、1%、2%、3%和4%NaCl盐溶液处理梭梭幼苗12h。测定体内SOD、CAT和POD活性,MDA和蛋白质含量,电导率。结果表明:梭梭幼苗在适当的NaCl胁迫下,体内能维持较高的保护酶活性;较低的膜脂过氧化作用和细胞膜透性,说明梭梭具有较强的耐盐性。  相似文献   

7.
外磁场对玉米幼苗脂质过氧化的影响   总被引:4,自引:0,他引:4  
用场强为1000,1400,1800GS的磁场处理玉米(ZeamayL.)种子,采收二、三叶期幼苗做为试验材料,以极谱氧电极法测超氧化物歧化酶(SOD)活性,滴定法测过氧化氢酶(CAT)活性,比色法测丙二醛(MDA)和谷胱甘肽(GSH)含量.结果表明,经磁场处理种子后,玉米幼苗的叶及根中MDA含量降低,SOD和CAT活性提高,GSH含量增高.揭示了外磁场可削弱玉米幼苗脂质过氧化作用  相似文献   

8.
分别用0、1%、2%、3%和4%NaCl盐溶液处理梭梭幼苗12h.测定体内SOD、CAT和POD活性,MDA和蛋白质含量,电导率.结果表明:梭梭幼苗在适当的NaCl胁迫下,体内能维持较高的保护酶活性;较低的膜脂过氧化作用和细胞膜透性.说明梭梭具有较强的耐盐性.  相似文献   

9.
不同程度的水分胁迫处理下,随着胁迫程度的加重,大豆幼苗叶片细胞摹相对透性和反映膜脂过氧化水平的丙二醛含量逐渐增加,并且质膜相对透性和MDA含量的高低与大豆口种的抗早能力呈负相关。  相似文献   

10.
以机体硒水平,GSH-Px,SOD的活性,相关的抗癌致癌元素的综合效应比值,食管癌死亡率与硒等元素的多元回归分析及MDA的含量等合指标,评价食管癌患者的硒营养状况,结果表明,食管癌患者的营养状况差,表现为:硒水平低、含硒酶GSG-Px以及抗氧自由基的SOD活性差,脂质过氧化加剧;MDA含量高将使核酸,蛋白质含等含氨基活性物质产生交联反应而使细胞失活,食管癌患者硒营养状况差,与癌肿的一定相关关系,是  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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