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为了有效回收利用洋葱皮中的活性成分,采用超临界二氧化碳萃取技术从洋葱皮中提取黄酮类化合物。经单因素试验及正交试验,确定最佳提取工艺为提取温度40℃,提取压力30 MPa,提取时间1.5 h,夹带剂流量0.40 mL/min,经测定该条件下黄酮的提取率为7.89%。 相似文献
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绞股蓝具有很强的抗氧化能力,为了确定绞股蓝抗氧化过程中起主要作用的功能成分,对绞股蓝进行初步分离、提取,并研究各提取片段的体外抗氧化活性。实验数据显示,在绞股蓝3种相提取物中,乙酸乙酯相在试验的浓度范围内所具有的抗氧化活性最强,是绞股蓝抗氧化作用的主要成分。 相似文献
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《农产品加工．学刊》2016,(16)
采用索氏抽提法提取茶叶中的咖啡因,以95%乙醇为提取剂,利用生石灰中和乙醇提取液中含有的单宁酸,使咖啡因从提取液中游离出来,然后采用升华法使咖啡因结晶,对提取出的咖啡因样品用红外光谱进行结构鉴定,确定其成分。主要测定了市售各类不同产地茶叶中咖啡因含量,并对其中一种茶叶——铁观音不同加工方法 (以其价位或等级作为参考)的咖啡因含量进行粗略评价。在试验过程中,对相关试验条件(如提取剂体积、升华时间等)作了初步探讨。 相似文献
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为研究2种中草药提取物对黑木耳发酵过程中活性成分产生的影响,分别向黑木耳发酵基础培养基中添加不同比例的刺五加及五味子提取液,培养6天后,采用比色法及HPLC法分析黑木耳多糖成分及腺苷含量;同时,采用HPLC法分析黑木耳发酵过程中2种中草药活性成分的含量变化。结果表明：刺五加、五味子的添加量分别为4、3 g/L对黑木耳发酵液中多糖的形成具有显著促进作用;刺五加、五味子的添加量分别为1、6 g/L对黑木耳菌丝体中腺苷的形成具有显著促进作用;在黑木耳发酵过程中,刺五加活性成分紫丁香苷及刺五加苷E降低到无法检测;五味子中木脂素成分存在增减变化。黑木耳发酵过程中存在活性成分的动态变化。 相似文献
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以乙醇水溶液为提取剂,从北芪菇中提取黄芪甲苷,薄层层析(TLC)分离和制备黄芪甲苷;通过对比质荷比(m/z)和官能团等对黄芪甲苷进行表征与分析。结果表明,乙醇-水=7∶3(V/V)作为提取剂,微波超声波处理后,多级萃取后得到正丁醇相;氯仿∶甲醇∶乙酸乙酯∶水=13∶7∶2∶2(V/V)展开后,经显色获得的色谱斑点与黄芪甲苷标准品斑点位置比对一致,Rf值为0.31;黄芪甲苷样品和标准品质谱波谱图和红外波谱图确定提取物为黄芪甲苷。样品中黄芪甲苷的熔点是295℃;旋光度是+56.4;比旋光度是+24.4。结果表明,TLC-MS-IR联用是一种具有独特优势的色谱波谱技术,能实现从微克量级的分离分析到克量级的分离制备,可用于天然产物粗提物的去除杂质和单个产物的精制,适用于从北芪菇中进行物质的制备分离。 相似文献
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Jens Jensen 《Euphytica》1979,28(1):47-56
Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans. 相似文献
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Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts 总被引：7，自引：0，他引：7
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed. 相似文献
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Hongyan WEI Jian ZHOU Jinguang LU Jingzheng SONG Qiongxi YU Zhihong JIANG 《Medicinal Plant》2019,(6):27-29
[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol... 相似文献
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C. J. Spurr D. A. Fulton P. H. Brown R. J. Clark 《Journal of Agronomy and Crop Science》2002,188(4):275-280
Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality. 相似文献
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Chunli TANG Fengxian ZHAO Hongxia CHEN Jiabao MA Jiangcun WEI Meiyan QIU Zhen XIE 《Medicinal Plant》2019,(6):60-65
[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination... 相似文献
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D. A. Bond G. J. Jellis G. G. Rowland J. Le Guen L. D. Robertson S. A. Khalil L. Li-Juan 《Euphytica》1993,73(1-2):151-166
Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses. 相似文献
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Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed. 相似文献
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[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho... 相似文献
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E. Keep 《Euphytica》1986,35(3):843-855
Summary Cytoplasmic male sterility (cms) is described in the F1 hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf
1) and recessive for the other (Rf
2).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph
3(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf
1(one of two dominant additive genes controlling early season leafing out) indicated that Rf
1and Rf
2were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf
1, and 0.15 for Lf
1-Sph
3were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph
3.It is suggested that competitive disadvantage of lf
1-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph
3. Poor performance of lf
1- (and possibly lf
2-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off). 相似文献
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Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques. 相似文献