共查询到20条相似文献，搜索用时 93 毫秒
1.
通过羟基自由基（·OH）、超氧阴离子（O2·- ）、亚硝酸根离子（NO2-）及DPPH自由基4种体外抗氧化模型,对铁皮石斛纳米粉和超微粉的体外抗氧化作用进行比较研究,对2种粉末的流动性、松密度、溶解性等物理特性,粒度及电镜扫描结构进行分析比较,并测定其悬浮液中多糖溶出速度及含量。结果表明：铁皮石斛纳米粉的多糖溶出速度及含量要高于超微粉;铁皮石斛纳米粉和超微粉水提取液对·OH、O2·- 、NO2-、DPPH自由基均具有较强的清除能力,且在一定范围内,清除率随浓度的增加而增大,呈现良好的量效关系;同一浓度时,纳米粉的清除率要明显高于超微粉,说明纳米粉具有更强的体外抗氧化能力;纳米粉的松密度、持水力、膨胀力、溶解性及水悬浮体系稳定性要高于超微粉,但流动性、润湿时间等参数不如超微粉;粒度及电镜分析表明纳米粉的细胞破碎程度更大,粒度更小,形状更不规则。 相似文献
2.
3.
核盘菌是危害十字花科作物生产的重要病原菌。核盘菌诱导寄主产生过量活性氧（ROS），造成寄主细胞死亡，硫氧还蛋白（Trx）在寄主抗氧化过程中起重要作用。筛选并鉴定硫氧还蛋白（Trx），分析其与核盘菌抗性的关系，将为植物抗菌核病育种提供基因资源。本研究通过生物信息学及转录组数据分析，从拟南芥中筛选到一个关键Trx基因AtTrx5。AtTrx5与甘蓝型油菜BnaA08g04320D的亲缘关系最近，氨基酸相似性为85%。油菜同源基因Trx5表现出上调表达。AtTrx5超表达植株在接种核盘菌24 h后的菌斑面积相比野生型（WT）减小30%～39%，而AtTrx5基因T-DNA突变体的菌斑面积比WT增加39.2%。在侵染过程中超表达转基因拟南芥中AtTrx5的表达量均高于WT，而T-DNA突变体中AtTrx5的表达量则低于WT。DAB染色、H2O2含量、·O2-含量测定结果表明，侵染过程中拟南芥T-DNA突变体中积累的ROS高于WT，超表达转基因拟南芥中积累的ROS少于WT。 相似文献
4.
以44种花卉为材料,比较其水提液DPPH·、O2·-、·OH的清除能力和还原力,并测定多酚和黄酮含量,研究自由基清除能力、还原力和多酚、黄酮含量之间的关系。结果表明：龙眼(Dimocarpus longgana)、荔枝(Litchi chinensis)、玫瑰(R. rugosa)、月季(R. chinensis)和桂花(O. fragrans)等花卉品种都表现出较好的自由基清除能力和还原力,较高的多酚含量和黄酮含量。3种自由基清除能力、还原力和多酚含量都存在显著(p＜0.05)或极显著(p＜0.01)相关性。除·OH清除率外,另外2种自由基清除能力、还原力和黄酮含量也存在显著(p＜0.05)相关性。因此,花卉的抗氧化活性和还原力与多酚含量呈正相关。 相似文献
5.
镧对镉胁迫下大豆幼苗 光合作用和活性氧代谢的影响 总被引：1，自引：0，他引：1
在盆栽条件下,研究了不同浓度的La对30μmol/L和50μmol/L Cd胁迫下的大豆幼苗生理效应。结果 表明,适量的La能在一定程度上缓解Cd胁迫所导致的叶绿素含量、叶绿体可溶性蛋白质含量、光合速率、叶绿体 Mg2 + - ATPase活性的降低;能有效增强或保护叶片抗氧化能力,降低超氧阴离子自由基(O2 · )产生速率、组织自动 氧化速率和H2O2 含量,防止膜透性的增加;适量的La能保持大豆叶片中超氧化物歧化酶( SOD)和抗坏血酸过氧 化物酶(AsA - POD)活性的相对稳定,维持活性氧的代谢平衡。La对30μmol /L Cd胁迫的缓解能力较强,而对 50μmol/L Cd胁迫的缓解能力较弱。La的最佳作用浓度为0. 30μmol/L,高于0. 50μmol/L的La则加剧Cd的毒害。 相似文献
6.
五种芽苗菜提取物抗氧化活性的比较 总被引：1，自引：0，他引：1
芽苗菜是普遍食用的保健型蔬菜,通过比较5种芽苗菜提取液对超氧阴离子自由基(O2-·)和羟基自由基(·OH)的清除率来研究5种芽苗菜的抗氧化活性。结果表明:5种芽苗菜不同浓度和不同部位取材提取液对超氧阴离子自由基(O2-·)和羟基自由基(·OH)清除率比较结果一致,香椿芽黑豆芽萝卜苗绿豆芽豌豆苗;5种芽苗菜叶对超氧阴离子自由基(O2-·)和羟基自由基(·OH)的清除率高于茎,但不同芽苗菜茎叶对自由基的清除率有差别;5种芽苗菜叶绿素、VC、类黄酮3种活性物质含量不同反映了抗氧化物质和抗氧化机制不同;叶绿素是影响抗氧化活性的因素,但其作用有限。 相似文献
7.
8.
树舌胞外富锌多糖体外抗氧化活性研究 总被引：1，自引：0，他引：1
利用树舌的深层发酵法获得胞外富锌多糖,从抗油脂过氧化、抑制羟自由基的产生、清除DPPH·和O2·- 4个方面,探讨树舌胞外富锌多糖抗氧化活性。结果表明：树舌富锌培养基内ZnSO4浓度在200 μg/mL时,可以显著提高胞外多糖的有机锌含量,使有机锌含量达0.67 mg/g,比对照组提高252％。有机锌对提高胞外多糖抗氧化能力有显著的效果,在多糖浓度为2.5 g/L,对油脂过氧化的抑制、清除羟自由基、DPPH·和O2·- 的能力分别比对照提高12.5％、26.83％、30％ 和20％。胞外富锌多糖抗氧化活性 相似文献
9.
干旱胁迫对多年生落花生生长和活性氧代谢的影响 总被引：7，自引：0，他引：7
采用盆栽法研究不同程度的土壤干旱胁迫对多年生落花生（Arachis duranensis krapov．＆ W．C．Greg）生长和活性氧代谢的影响。结果表明，随着土壤干旱胁迫的加剧，多年生落花生茎叶干物质积累量和叶片相对含水量（RWC）逐渐下降，根重、超氧阴离子自由基（O2^-）、丙二醛（MDA）、质膜透性（RPP）、超氧化物歧化酶（SOD）及过氧化物酶（POD）均有不同程度的上升。相关分析结果表明，在土壤干旱胁迫下，多年生落花生各参数间存在一定的协同性，其中茎叶干物质积累量与O2^-，MDA，RPP；RPP与O2^-；POD与O2^-；POD与SOD均呈极显著的线性相关（a〈0．01）。 相似文献
10.
在25℃,光合光量子流通量0.35m mlo·m~(-2)·S~(-1)下,香荚兰叶片的需 CO_2的释氧速率为1.59μmol O2·m~(-2)·S~(-1)。间歇暗期1分钟,照光叶片需 CO_2释氧速率能提高32.7%。叶片需CO_2释氧速率以25℃时为最高。温度升高至30和34℃时,叶片需 CO_2释氧速率降低。在4℃下8小时或10小时,香荚兰叶片的需 CO_2释氧速率和呼吸速率均有下降,但幅度较小。表明香荚兰能耐短期零上低温。在较高光强(0.9 m mol·m~(-2)·S~(-1)光量子)下0.5或1小时,叶片表现不同程度的光抑制现象。香荚兰的茎含有叶绿素 a 和叶绿素 b,a/b 为1.13,较叶片低。茎组织的丙酮提取液的吸收光谱表现胡萝卜素和叶黄素的吸收需 CO_2的释氧速率为2.86μmolO_(2·g) 鲜重~(-1)·h~(-1),相当叶片的92.5%。表明茎是香荚兰光合作用组织的一部分。 相似文献
11.
Sorghum and millet phenols and antioxidants 总被引：5，自引：2，他引：5
Sorghum is a good source of phenolic compounds with a variety of genetically dependent types and levels including phenolic acids, flavonoids, and condensed tannins. Most sorghums do not contain condensed tannins, but all contain phenolic acids. Pigmented sorghums contain unique anthocyanins that could be potential food colorants. Some sorghums have a prominent pigmented testa that contains condensed tannins composed of flavan-3-ols with variable length. Flavan-3-ols of up to 8–10 units have been separated and quantitatively analyzed. These tannin sorghums are excellent antioxidants, which slow hydrolysis in foods, produce naturally dark-colored products and increase the dietary fiber levels of food products. Sorghums have high concentration of 3-deoxyanthocyanins (i.e. luteolinidin and apigenidin) that give stable pigments at high pH. Pigmented and tannin sorghum varieties have high antioxidant levels that are comparable to fruits and vegetables. Finger millet has tannins in some varieties that contain a red testa. There are limited data on the phenolic compounds in millets; only phenolic acids and flavones have been identified. 相似文献
12.
Summary Between 1993 and 1998 205 different potato cultivars and 1220 accessions/genotypes of wild and cultivated potato species from
the IPK Genebank Gatersleben were evaluated. Parameters interesting for starch isolation and especially for the use of starch
were determined. Altogether, there was a higher variability in wild potato species than in cultivated potatoes for all characteristics
investigated: dry matter content, starch content, protein content, amylose content and mean particle diameter of starch granules. 相似文献
13.
种子加工、检验理论与技术现状及思考 总被引：3，自引：0，他引：3
种子加工及检验是种子向市场流通的关键，是商业化育种中赋予种子商品属性不可或缺的环节。种子加工、检验理论与技术的研究是完善种业产业链、实现规模化商业育种、夯实“育繁推一体化”种业科学的重要一环。中国的种业科学技术体系正在形成与完善之中，受制于行业发展水平，种子加工及检验理论与技术相对薄弱。本文回顾了种子加工及检验理论与技术研究发展历程，提出了完善中国种业科学发展的策略与建议。围绕种业发展的需要，在做好品种优质化繁育的基础上，分析种子加工及检验理论与技术的新方向和新需求，加强种业应用性研究，建立先进的种子质量检验体系，研制适合现代种业发展需求的种子加工设备，打造种子加工产业标准化生产体系，完善种业科学技术学科建设，促进种业产业持续健康发展。 相似文献
14.
ZHU Mingdong WEI Xiangjin XIE Hongjun TANG Guohua ZENG Xiaoshan WANG Jianlong HU Peisong YU Yinghong 《中国水稻科学》2019,33(5):401-406
Seed processing and testing hold the key to the market circulation of seeds, and are an indispensable link in commercial breeding to endow seeds with commodity attributes. The research of seed processing and testing theory and technology is an important link in improving the seed industry chain, realizing large-scale commercial breeding and consolidating the seed industry science of ‘integration of breeding, propagation and promotion’. The scientific and technological system of seed industry in China is being formed and perfected, which is subject to the development level of the industry. The theory and technology of seed processing and testing are relatively weak. We reviewed the development of seed processing and testing theory and technology, and put forward strategies and suggestions to improve the sound development of China’s seed industry. In order to meet the needs of seed industry development and on the basis of high quality breeding of varieties, the new directions and demands of seed processing and testing theory and technology were analyzed. We will work to strengthen the applied research of seed industry, establish advanced seed quality inspection system, improve seed processing equipment suitable for the development needs of modern seed industry, establish standardized production system of seed processing industry, develop the scientific and technological disciplines of seed industry, and promote the sustainable and healthy development of seed industry. 相似文献
15.
《Journal of Crop Improvement》2013,27(1):313-324
Summary Arbuscular mycorrhizae were inoculated into phosphorus-deficient soil fertilized with either organic or chemical fertilizer with cucumber (Cucumis sativus L.) as the first crop and lettuce (Lactu-ca sativa L.) as the second crop but without additional fertilization and AM inoculation. AM increased dry matter and fruit yield of cucumber significantly in the unfertilized, organic-fertilized and P-deficient plants compared with the fully chemical-fertilized plants. AM inoculation increased the available phosphorus in plant and soil by around 30% for all treatments except for those chemically-fertilized. The rate of AM infection did not differ significantly among the fertilization treatments, but the infection intensity was higher in unfertilized, organic-fertilized and phosphorus-deficient treatments than chemical-fertilized treatment. The residual effects of AM-inoculated to cucumber were evident for lettuce in all pre-treatments that were unfertilized and un-inoculated for the second cropping. Without P-fertilization, neither crop could grow optimally even when the soil was inoculated with AM, suggesting that AM could not serve as a substitute for phosphorus fertilizer. However, the other beneficial effects of AM on crop growth and yield could not be fulfilled with phosphorus fertilizer. 相似文献
16.
种子加工及检验是种子向市场流通的关键,是商业化育种中赋予种子商品属性不可或缺的环节。种子加工、检验理论与技术的研究是完善种业产业链、实现规模化商业育种、夯实"育繁推一体化"种业科学的重要一环。中国的种业科学技术体系正在形成与完善之中,受制于行业发展水平,种子加工及检验理论与技术相对薄弱。本文回顾了种子加工及检验理论与技术研究发展历程,提出了完善中国种业科学发展的策略与建议。围绕种业发展的需要,在做好品种优质化繁育的基础上,分析种子加工及检验理论与技术的新方向和新需求,加强种业应用性研究,建立先进的种子质量检验体系,研制适合现代种业发展需求的种子加工设备,打造种子加工产业标准化生产体系,完善种业科学技术学科建设,促进种业产业持续健康发展。 相似文献
17.
通过比较分析芸薹属多倍体复合种与其祖先二倍体基本种在花柱、柱头大小、角果长度、宽度、种子直径 及种子干重变化上的异同,发现多倍体复合种在这些发育性状上表现出处于两个祖先二倍体亲本之间,或只偏向 于其中一个祖先亲本。同一个多倍体品种在不同发育性状上具有不同的表现,即在某一发育性状上偏向于其祖先 亲本之一,而在另一发育性状上偏向其另一祖先亲本。 相似文献
18.
Effects of crop density and tillage system on grain yield and N uptake from soil and atmosphere of sole and intercropped pea and oat 总被引：1，自引：0，他引：1
Pea (Pisum sativum L.) and oat (Avena sativa L.) were grown as sole and mixed crops in various densities under two different tillage systems on a loess soil near Göttingen/Germany in a 2-year field experiment (2002/2003). In the conventional tillage system a mouldboard plough (CT) was used and in the minimum tillage system a rotary harrow (MT) was employed. The effect of crop density and tillage system on the grain dry matter and grain N yields, N2 fixation and soil N uptake were determined to address the following questions: (i) which mixture compositions exhibit the highest grain yields compared to the sole crops, (ii) which mixture compositions also fix a high level of N2 and leave low levels of residual inorganic soil N after harvest, and (iii) whether the intercrop advantage is influenced by the tillage system. For (i) the result in 2002 showed that the highest grain yields of both sole cropped pea and oat and intercropped pea and oat were achieved at the highest densities. In 2003, when the inorganic soil N content was higher and weather conditions were warmer and drier, grain yields were significantly higher than in 2002, but sole as well as intercropped pea and oat gave their highest grain yields at lower densities. For both years and tillage systems, the highest intercrop advantages were achieved in mixtures with densities above the optimal sole crop densities. The result for (ii) was that a distinctly higher proportion of nitrogen was derived from the atmosphere (Ndfa) by intercropped pea than by sole cropped pea. However, the uptake of soil N by intercropped pea and oat was not reduced in comparison with that of sole cropped oat as the decrease in the uptake of N from the soil by oat at lower oat densities in the mixture was compensated for by the soil N uptake of pea. Additionally, the Nmin-N content of the soil following the mixtures and sole cropped oat did not differ, especially in the deeper soil layers because oat in mixture was forced to take up more soil N from deeper layers. Therefore, the risk of soil N losses through leaching after mixtures was lower compared to sole cropped pea. The tillage system (iii) had no significant influence on grain yield and soil N uptake, but N2 fixation and the competitive ability of intercropped pea were higher under CT than with MT. An additional result was that intercropping led to a significantly increased grain N content of both pea and oat compared to the sole crops. The increase in grain N content from sole to intercrop was from 3.30 to 3.42% for pea and from 1.73 to 1.96% for oat as a mean for both years and tillage systems. The present study confirms that growing pea and oat as intercrops highlights potential economic and environmental benefits which still need to be understood in more detail in order to exploit intercropping to a greater extent. 相似文献
19.
20.
Combined nitrogen and sulphur fertilisation and its effect on wheat quality and protein composition measured by SE-FPLC and proteomics 总被引：2，自引：1，他引：2
N.E.S. Flte K. Hollung L. Ruud T. Sogn E.M. Frgestad H.J. Skarpeid E.M. Magnus A.K. Uhlen 《Journal of Cereal Science》2005,41(3):357-369
Soil sulphur deficiency, which is increasingly prevalent in Western Europe, lowers wheat yields, and also affects the gluten quality of the flour. Differences in S availability may change the proportion of S-poor to S-rich gliadins and glutenin subunits. This may cause unpredictable and unwanted variations in wheat quality. The combined effects of nitrogen (N) and sulphur (S) fertilisers and split application of S and N on wheat gluten quality and composition were investigated. The results revealed effects of S fertilisation on dough quality. At high N fertilisation levels significant responses to S fertilisation were found which emphasised the need for precision application of S in intensive wheat production systems. Protein fractionation by SE-FPLC showed that quality differences were associated with changing proportions of high Mr polymeric proteins. Changes in protein composition of salt soluble proteins were also confirmed by proteomics. Glyceraldehyde-3-phosphate dehydrogenase and one of the serpin protein spots increased at high N, combined with the lower S level. The enzymes also increased in samples with increased S fertilisation combined with low N, but was not changed at higher N levels. Furthermore, at high N the serpin protein spot, and also a 27 K protein and one unidentified protein spot decreased with increasing S. 相似文献