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不同因素对草莓试管苗玻璃化的影响 总被引：1，自引：0，他引：1
以“丰香”草莓丛生芽为外植体,采用正交实验设计,研究了6-BA、琼脂、铵离子不同浓度组合对草莓试管苗玻璃化的影响,同时测定了玻璃化试管苗与正常苗的生理指标差异.结果表明:3种因素对草莓试管苗玻璃化均有显著影响,影响大小依次为6-BA＞铵离子＞琼脂；能有效降低试管苗玻璃化的组合为1.0 mg/L 6-BA+6.0 g/L琼脂+1650 mg/L铵离子,增殖倍数也较高；玻璃化苗的组织含水量和膜透性较正常苗高,可溶性糖含量则相反；玻璃化苗的叶绿素含量较正常苗显著降低,叶绿素a/叶绿素b在正常苗与玻璃苗间无显著差异,玻璃化苗较正常苗超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性降低,过氧化物酶(POD)活性升高. 相似文献
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为了解决果树试管苗生根难、移栽难、当年移栽苗长得小等问题,国内场玉梅等1983年曾报道了苹果试管苗大树高接的试验及经验。葡萄试管苗大树高接的研究,国内外尚未见报道。1985年我们进行了葡萄试管 相似文献
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‘黄冠’梨正常试管苗与玻璃化苗生理生化及超微结构的比较研究 总被引：1，自引：0，他引：1
以正常和玻璃化‘黄冠’梨试管苗为试材进行组培快繁、生理生化及组织结构比较研究。结果表明：玻璃化苗较正常苗增殖能力显著降低,增殖出的试管苗仍为玻璃化苗,并且玻璃化程度加重;干物质积累较正常苗低31.3%,淀粉含量低29.57%,而可溶性糖含量高13.92%;叶绿素a、叶绿素b及叶绿素总含量分别降低40.16%、43.24%和39.52%;ZR、IAA、GA含量,GA/IAA和ZR/IAA均高于正常苗,而ZR/GA显著低于正常苗;叶绿体数量减少、体积变小、类囊体叠跺不整齐,细胞核畸形或缺失。碳水化合物含量较低、激素代谢紊乱、光合结构破坏及细胞核物质减少是梨玻璃化苗的重要特征,可能是后代增殖能力显著降低的主要因素。 相似文献
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探讨外源活性氧物质（ROS）引起试管苗玻璃化,以及活性氧清除剂对试管苗玻璃化的缓解效应和机理,以大蒜品种‘二水早’试管苗为材料,研究外源过氧化氢（H2O2）及H2O2 + 活性氧清除剂抗坏血酸（AsA）处理下试管苗玻璃化及活性氧代谢的变化。结果表明：外源H2O2处理使大蒜试管苗内源超氧阴离子产生速率和H2O2含量提高,玻璃化率和玻璃化程度提高。玻璃化现象的发生较内源大量发生滞后,与H2O2显著积累同步。外源H2O2处理0 ~ 8 d,超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性有上升趋势并显著高于对照,但在8 d后抗氧化酶活性或者下降（SOD、CAT）,或增加缓慢（POD）,而内源抗氧化物质AsA含量在处理8 d时显著低于对照。在外源H2O2处理的同时添加外源AsA,因外源H2O2引起的内源的产生和H2O2的积累减少,SOD、POD、CAT等抗氧化酶活性保持持续上升趋势,并在处理后期高于添加H2O2的处理及对照,内源AsA含量保持较高水平并显著高于外源H2O2处理;同时玻璃化率增加缓慢。综上所述,外源H2O2可提高大蒜试管苗内源的产生速率和H2O2含量,降低抗氧化系统的抗氧化能力,进而导致试管苗玻璃化加重;添加外源抗氧化物质AsA可缓解的产生和H2O2的积累,对试管苗玻璃化发生有控制效果。 相似文献
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Fruit cracking after rain limits the production of a number of crops, including some Ribes species. To gain a better understanding of the factors involved in cracking, fruit growth, deposition of the cuticular membrane (CM), water uptake and fruit cracking were studied in black currant (Ribes nigrum L. cv. Zema), gooseberry (Ribes uva-crispa L. cv. Rote Triumph), and jostaberry (Ribes nidigrolaria B. cv. Jostine). Fruit surface area and fresh mass increased continuously throughout development, whereas deposition of the CM was biphasic. CM mass per fruit increased rapidly up to 42, 41, and 49 days after full bloom (DAFB) in black currant, gooseberry, and jostaberry, respectively. Thereafter, CM mass per fruit remained constant in gooseberry and jostaberry or increased at a lower rate in black currant. The cessation of or reduced rate of CM deposition resulted in a decrease in CM mass per unit area in all berries. Elastic strain of the CM at maturity averaged 23.8% and 19.5% in gooseberry and jostaberry, respectively, and only 8.2% in black currant. Microcracks in the CM were observed first in gooseberry and jostaberry 64 DAFB, whereas there were no microcracks in black currant. Water uptake into mature detached berries was linear over 2 h of incubation. Rates of uptake were highest in gooseberry followed by black currant and jostaberry. Relative uptake was similar via the cut end of the pedicel (32.1%), the apex of the fruit (34.7%) and the fruit surface (33.2%). Rates of water uptake through the fruit surface were positively related to surface area. Average fruit water potential for black currant, gooseberry, and jostaberry was −2.14 ± 0.17, −1.24 ± 0.03, and −1.89 ± 0.20 MPa, while the permeability for osmotic water uptake was 7.7 ± 0.4 × 10−8, 5.2 ± 0.1 × 10−8, and 3.3 ± 0.3 × 10−8 m s−1. Incubating whole fruit in deionized water for 72 h resulted in more cracked jostaberries (94%) than black currants (74%) or gooseberries (50%). A comparison of our findings in Ribes berries with published data for the sweet cherry drupe revealed that the berries fitted the relationships established in sweet cherry among fruit growth, cuticle deposition, strain of the cuticle, microcracking, permeability for osmotic water uptake, frequency of stomata and cracking. The Ribes berries were less susceptible to cracking than sweet cherry. 相似文献
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Mortalin(mtHSP70/HSP75/Grp75/TRAP-1/PBP74) is an essential mitochondrial chaperone and is believed to regulate multiple cellular functions ranging from cell survival, cell proliferation, stress response, mitochondrial biogenesis and intracellular trafficking. Recent studies have shown that mortalin is relevant to the pathogenesis of Alzheimer's disease(AD) and Parkinson's disease(PD). Proteomic studies demonstrate the differential expression of mortalin not only in the models of AD or PD but also in PD human brains as compared to the controls. Mortalin seems to modulates the development of diseases through association with the critical molecules such as apoE, amyloid β-protein, amyloid precursor protein(APP) in AD, and α-synuclein, DJ-1, PINK1 in PD. Mortalin may regulate PD development via the pathways involving mitochondrial and proteasomal functions as well as oxidative stress. Furthermore, it is reported that mortalin participates in the pathological processes of several other neurological disorders, such as ischemic brain injury, absence seizure and Friedreich's ataxia(FRDA). 相似文献
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中国''''99昆明世界园艺博览会蔬菜瓜果园 总被引：1，自引：0，他引：1
蔬菜瓜果园作为中国’99昆明世界园艺博览会六大专题展园之一 ,占地 4 90 0ｍ2 。园内以农舍草屋为中心 ,通过瓜架、篱笆、草亭及蔬菜瓜果栽培 ,构出一幅农家乐园式的田园风光。另外 ,通过集中展示中国蔬菜瓜果的科技生产水平 ,丰富的资源优势 ,色彩缤纷、新奇别致的蔬菜瓜果品种 ,来突出本次世博会的主题“人与自然 ,和谐发展———迈向 2 1世纪” ,从而展现“蔬菜瓜果园艺是人类赖以生存的重要食源和艺术”为主题思想的蔬菜瓜果园内涵。 蔬菜瓜果园位于世博园主入口世博大道南侧 ,与盆景园、药草园相邻。在总体布局、栽培上充分运用园… 相似文献
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以杂种榛优良品系为试材,分析氮、磷、钾、钙与贮藏物质的相关性。结果表明:氮、磷、钾和钙与脂肪显著或极显著正相关。氮、磷和钙与蔗糖显著或极显著正相关,‘82-11’品系中的磷和钾与可溶性总糖显著或极显著正相关,‘84-237’品系中的钙与可溶性总糖显著正相关,‘84-402’品系中的磷素与可溶性总糖显著正相关。 相似文献
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江汉平原是国家优质粮食、优质棉花和双低油菜重要生产基地,也是湖北省西瓜主产区。种植西瓜对增加农民收入、丰富市场、发展农村经济、提高土地利用率具有重要作用。江汉平原西瓜生产的突出特点是间作套种,早在20世纪70年代就推广了“麦／／瓜-稻”这种水旱、粮经作物配套种植的优化模式．并获得原荆州地区科技进步二等奖。由于西瓜间作套种提高了单位面积的经济效益、 相似文献
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Growing a resilient landscape depends heavily on finding an appropriate match between the scales of demands on ecosystems by human societies and the scales at which ecosystems are capable of meeting these demands. While the dynamics of environmental change and ecosystem service provision form the basis of many landscape ecology studies, enhancing landscape resilience is, in many ways, a problem of establishing relevant institutions that act at appropriate scales to modify and moderate demand for ecosystem services and the resulting exploitation of ecosystems. It is also of central importance for landscape sustainability that institutions are flexible enough to adapt to changes in the external environment. The model provided by natural ecosystems suggests that it is only by encouraging and testing a diversity of approaches that we will be able to build landscapes that are resilient to future change. We advocate an approach to landscape planning that involves growing learning institutions on the one hand, and on the other, developing solutions to current problems through deliberate experimentation coupled with social learning processes. 相似文献
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Harold S. J. Zald Thomas A. Spies Manuela Huso Demetrios Gatziolis 《Landscape Ecology》2012,27(8):1197-1212
Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors at multiple spatial scales. The purpose of this research was to quantify spatiotemporal patterns of meadow invasion; and how climate, larger landforms, topography, and overstory trees have interactively influenced tree invasion. We combined airborne Light Detection and Ranging (LiDAR) characterizations of landforms, topography, and overstory vegetation with historical climate, field measurements of snow depth, tree abundance, and tree ages to reconstruct spatial and temporal patterns of tree invasion over five decades in a subalpine meadow complex in the Oregon Cascade Range, USA. Proportion of meadow occupied by trees increased from 8?% in 1950 to 35?% in 2007. Larger landforms, topography, and tree canopies interactively mediated regional climatic controls of tree invasion by modifying depth and persistence of snow pack, while tree canopies also influenced seed source availability. Landscape context played an important role mediating snow depth and tree invasion; on glacial landforms tree invasion was negatively associated with spring snowfall, but on debris flows tree invasion was not associated with snow fall. The importance of snow, uncertain climate change impacts on snow, and mediation of snow by interacting and context dependent factors in complex mountain terrain poses substantial hurdles for understanding how these ecotones may respond to future climate conditions. 相似文献
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Spatial patterns of fire occurrence in Catalonia,NE, Spain 总被引：2，自引：0，他引：2
In this paper, we analyse spatial patterns of fire occurrence in Catalonia (NE Spain) during 1975–98. Fire scar maps, discriminated by means of 30–60 m resolution remote sensing imagery, have been used as a source of fire occurrence. We employ several visual or analytical approaches to interpret fire occurrence in this region, such as those of Minnich and Chou (1997), Ricotta et al. (2001) or Krummel et al. (1987). Crucial spatial patterns such as fire size distribution, fire frequency distribution, spots and residual vegetation islands are documented. In addition, several geographical layers were overlaid with burned area maps in order to determine interactions between fire occurrence and environmental parameters such as altitude, slope, solar radiation, and burned land cover. Assuming that fire occurrence is well determined by such a posteriori empirical factors we detect areas most prone to fire in this region and aim to enhance the local forest management and conservation plans. 相似文献
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Richard E. Toth 《Landscape Ecology》1988,1(4):193-201
A soft paradigm for landscape analysis is presented. This paradigm focuses on the analysis of function first, and then on structure. The objective is to determine which factors are operationally significant, how these factors bring about change, and how they define the spatial characteristics of landscapes. 相似文献