共查询到17条相似文献，搜索用时 62 毫秒
1.
温度对水稻突变体W1叶色及叶绿素生物合成的影响 总被引：29，自引：0，他引：29
本文研究了温度对水稻突变体W1叶色及叶绿素 (Chl)生物合成的影响。W1是温敏型叶色突变体 ,叶色转变的临界温度约为 2 3℃。在高温下 ,突变体W1的Chl和类胡萝卜素 (Caro)含量与对照无显著的差异 ,幼苗呈绿色 ;低温 (1 5～ 2 0℃ )下W1的Chl和类胡萝卜素 (Caro)含量明显较低 ,表现白化。突变体W1白化苗中的Chla和Chlb含量同时下降 ,Caro Chl的比值增大 ,说明该突变体属于不是由Caro降低而导致的总叶绿素缺陷型。白化苗中Chl生物合成的中间产物原叶绿素 (酸 ) (Pchl)、镁原卟啉 (Mg proto)、原卟啉IX(ProtoIX)含量减少 ,而δ 氨基酮戊酸 (ALA)和胆色素原(PBG)大量积累 ,证明突变体W1低温下Chl生物合成卟啉原形成部位受阻 相似文献
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Ce(Ⅲ)对UV-B胁迫下大豆幼苗光呼吸的影响 总被引：1，自引：0，他引：1
采用水培法研究Ce(Ⅲ)对紫外辐射(UV-B0.15Wm-2,0.45Wm-2)胁迫下大豆(Glycine max)幼苗光呼吸速率(Pr)、光合速率(Pn)和叶绿素(Chl)含量的影响.实验结果表明与CK相比,元UV-B胁迫时20mg·L-1CeCl3能够有效提高Pr和Pn;UV-B处理使Pn与Chl含量降低,Pr增加;Ce UV-B组的Pr、Pn和Chl含量曲线走势均高于UV-B组.通过对Pr、Pn和Chl含量3项指标研究表明,20mg·L-1CeCl3能提高UV-B胁迫下大豆幼苗的Pr、Pn和Chl含量,通过提高Pr可消耗过多的光能,减轻UV-B辐射对大豆幼苗光合器官的伤害.抑制UV-B辐射胁迫下大豆幼苗Pn的下降,缓解Chl的降解,增强植物的抗逆性. 相似文献
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外源ALA对盐胁迫下夏枯草幼苗抗氧化能力与光合特性的影响 总被引：2，自引：0，他引：2
为探讨外源5-氨基乙酰丙酸(ALA)对盐胁迫下植物生长的缓解作用,以夏枯草为试验材料,研究1.25~10.00 mg·L~(-1)ALA对70 mmol·L~(-1)盐胁迫下夏枯草幼苗叶片和根系的抗氧化酶活性、叶片的叶绿素含量与光合特性的影响。结果表明,1.25~5.00 mg·L~(-1)ALA处理均可不同程度地提高盐胁迫下夏枯草幼苗叶片和根系过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)的活性及可溶性糖含量;增加夏枯草叶片的叶绿素a(Chl a)、叶绿素b(Chl b)、总叶绿素(Chl a+b)及类胡萝卜素(Car)含量;提高净光合速率(Pn)、气孔导度(Gs)与蒸腾速率(Tr),降低胞间CO2浓度(Ci)。外源ALA可以通过提高抗氧化酶活性和渗透调节物质的含量,增强叶片的光合作用,进而缓解盐胁迫对夏枯草幼苗产生的伤害,从而提高夏枯草幼苗的抗盐能力,ALA浓度以5.00 mg·L~(-1)最佳。本研究结果为探明ALA缓解夏枯草盐胁迫危害的作用机理提供了理论依据。 相似文献
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Ce（Ⅲ）对UV-B辐射胁迫下大豆幼苗N、P含量的影响 总被引：1，自引：0，他引：1
在温室模拟UV-B胁迫下,采用水培法研究稀土Ce(Ⅲ)对大豆(Glycine max)幼苗N、P吸收以及N代谢相关酶活性的影响.结果显示:UV-B辐射胁迫下,大豆幼苗叶片硝酸还原酶 (Nitrate reductase,NR)活性、硝态氮含量、磷含量较对照组均有显著下降,说明UV-B辐射严重抑制NR活性、使叶片内硝态氮(NO-3)和磷含量减少,而且高强度、长时间辐射时的抑制作用更大;而适宜浓度CeCl3(20mg*L-1)处理能提高叶片中NO-3和磷含量,缓解T1、T2胁迫下NO-3和磷含量的减少. 相似文献
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镁原卟啉Ⅸ甲基转移酶(ChlM)是叶绿素合成过程中的关键酶,对光合自养生物中叶绿素合成、叶绿体的正常发育以及光合作用的顺利进行起到至关重要的作用。ChlM不仅影响着光系统Ⅰ(PSⅠ)和光系统Ⅱ(PSⅡ)的形成以及脱落酸(ABA)的信号转导,还可以通过调控镁螯合酶H亚基基因(ChlH)表达而影响镁螯合酶活性。ChlM的产物可能参与叶绿体到细胞核的反向信号转导,同时,ChlM受到光照、叶绿体内氧化还原状态和叶片中叶酸含量等因素的影响。本文主要综述镁原卟啉Ⅸ甲基转移酶的结构特点、作用机制、酶活性调控及其参与的代谢调节,并展望镁原卟啉Ⅸ甲基转移酶的研究前景,以期为进一步深入研究并提高植物光合效率提供参考。 相似文献
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5-氨基乙酰丙酸(ALA)为高等植物中叶绿素等卟啉类化合物的生物合成前体,在促进作物生长、增强抗逆性及提高产量方面发挥着重要作用。为探究ALA对番茄果实成熟过程中品质和矿质元素含量的影响,本研究以原味1号品种为试验材料,向绿熟期番茄果实表面涂抹不同浓度(0、50、100、200、300 mg·L-1)ALA溶液,筛选出促进设施栽培番茄成熟及品质形成的最佳ALA施用浓度,并进一步研究其对设施番茄果实成熟过程中硬度、可溶性固形物以及矿质元素含量的影响。结果表明,外源ALA通过降低果实硬度促进了果实的成熟,并通过提高番茄果实中可溶性固形物含量提升了果实品质。另外,在坐果后40 d,200 mg·L-1ALA处理的K、Ca和Fe元素含量分别比对照提高了21.82%、56.25%和12.86%,但P、Mg和Cu元素含量分别比对照降低了9.92%、21.74%和25.00%。相关性分析结果表明,可溶性固形物含量与K含量呈正相关关系,与Cu含量呈负相关关系;果实硬度与K含量呈负相关关系。成熟期番茄果实中P含量与Cu含量呈正相关,与Mn、K和Ca含量呈负相关... 相似文献
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Suyundukov Ya. T. Suyundukova M. B. Bezuglova O. S. Khabirov I. K. Khasanova R. F. Semenova I. N. Rafikova Yu. S. Ilbulova G. R. 《Eurasian Soil Science》2022,55(1):27-35
Eurasian Soil Science - The results of the study of the properties of urban soils of the city of Sibay located in the mining region of the Republic of Bashkortostan are presented. A specific... 相似文献
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Kholodov V. A. Farkhodov Y. R. Yaroslavtseva N. V. Ziganshina A. R. Maksimovich S. V. 《Eurasian Soil Science》2022,55(7):998-1004
Eurasian Soil Science - Layers were step-by-step removed from macroaggregates (2–1 mm in diameter) of Protocalcic Chernozems via successive abrasion in a revolving rotator during 5, 10, 15,... 相似文献
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《Communications in Soil Science and Plant Analysis》2012,43(15-16):1631-1646
Abstract Brazil has approximately 30 million hectares of lowland areas, known locally as “Varzea,”; distributed throughout the country. Soils in these areas have the potential to support agricultural production, but very little is known about their fertility. The current experiment was undertaken to characterize the chemical and physical properties of representative “Varzea”; soils collected at 0–20, 20–40, 40–60, and 60–80 cm depth intervals from 23 sites in Goias State of Brazil. Organic matter contents averaged 42 g/kg in the surface 20 cm of soil and should make a significant contribution to overall nutrient availability. Soil pH increased slightly with depth from a mean value of 5.2 in the surface 20 cm of soil to a mean value of 5.4 in the 60–80 cm depth interval. Several soils had exchangeable Al values ≥ 1.0 cmol Al/kg, but soil Al saturation was generally less than the 60% level frequently associated with Al toxicity. However, cereal and legume production could benefit from lime addition in many of these soils. Although base saturation was fairly low in some soils, exchangeable Ca and Mg levels were, in general, adequate throughout the profile. Extractable P levels were adequate in most surface soil samples. Extractable K levels in these soils were generally low, and the application of K fertilizers should be beneficial, especially in conjunction with lime addition. The high clay content “Varzea”; soils of the Brazilian lowlands have some drainage problems but generally exhibit favorable chemical properties for crop production when compared to soils of the well‐drained Cerrados. 相似文献
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Ye. V. Rogozhina N. V. Kostina L. S. Malyukova 《Moscow University Soil Science Bulletin》2011,66(1):32-35
An estimation of potential nitrogen-fixing activity of various soil types under agrophytocenoses of tea, filbert, peach, and
pawpaw which grow in the area of Greater Sochi is given. High indicators of nitrogen fixation activity in the soil in the
course of vegetation were characteristic of agrocenoses of pawpaw, peach, and filbert. The lowest level of nitrogen fixation
was noted in the soil of a tea plantation. A negative correlation dependence of potential nitrogen-fixing activity on the
acidity of the soil solution was established. A study of the seasonal dynamics of the activity of nitrogen fixation of soils
of agrocenoses of the subtropical zone of Russia made it possible to distinguish a less active winter and more active spring-summer-autumn
periods. 相似文献
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物联网是一个集信息通信、数据交换、传感器技术与软件工程于一体的综合性产业,探讨和分析了物联网的结构体系与发展中遇到的安全问题。 相似文献
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荔枝种子从果实中剥离出来后, 即使在室内条件下, 也极易失水干缩, 潮湿环境中又易发霉而腐烂。扫描电镜观察表明: 种皮上布满纹孔, 水分散失面积很大; 种脐部为疏松的海绵组织, 且营养丰富。据此, 生产上应对种子彻底清洗, 并保存于适当湿度的环境中, 以提高其发芽率。 相似文献
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The rate of popping of popcorn was measured in oil and in air. Kinetic data for lifetimes of individual kernels from a large population were obtained in oil at six constant temperatures (180–250°C) and also in an air‐popper at 202°C. The data are characterized by an induction period, which is, significantly, followed by a first‐order decrease in the number of unpopped kernels versus time. The activation energy for the first order process is 166.7 kJ/mol between 180 and 210°C, and 53.8 kJ/mol between 210 and 250°C. These data are consistent with a model that assumes 1) that the rate of heat transfer into a kernel follows Newton's law of cooling; 2) that in a sample of kernels there exists a distribution of critical pressures; 3) that for an individual kernel, the probability of popping is directly proportional to the difference between the internal aqueous vapor pressure and the kernel's critical pressure; and 4) that the measured rate constant at any temperature is an average overall of the kernels in the sample with critical pressures equal to or less than the internal aqueous vapor pressure. Minimum popping temperatures predicted by the model are 181 ± 2°C (oil) and 187 ± 2°C (air), in good agreement with previously reported direct measurements. 相似文献
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三门峡水库库岸坍塌成因分析与防治措施研究 总被引：10，自引：0，他引：10
三门峡水库自1960年9月蓄水运行以来,库岸坍塌现象频繁发生,平均每年塌岸0.5～0.7亿m3.指出了造成库岸坍塌的原因主要是地质环境的影响以及水力条件的变化;不同的地形、地貌、地质结构和岩性特征,表现了不同的塌岸强度,其中黄土塬区为极强塌岸段,黄河Ⅱ级阶地为强烈塌岸段,黄河Ⅰ级阶地为中等强烈塌岸段;分析了引起库岸坍塌的主要水力条件有大气降水、地表水和地下水,并且不同水力条件及其变化特征,对库岸坍塌影响的方式和程度也不同;最后给出了防治库岸坍塌应采用标本兼治的原则,治标是指对塌岸进行必要的加固、支挡、衬砌等;治本就是根据引起塌岸的原因以及不同地质环境条件下的塌岸特征和水力条件,因地制宜,因害设防,从根本上进行综合治理. 相似文献