益智总黄酮超声辅助提取工艺的响应面法优化及其抗氧化活性评价

为优化益智总黄酮超声辅助提取工艺,并评价其抗氧化活性,以益智总黄酮提取率为指标,在单因素试验考察甲醇浓度、超声时间及液料比对总黄酮提取率影响的基础上,采用响应面试验设计优化了超声辅助提取工艺,利用DPPH自由基法、ABTS自由基法和FRAP法评价了其体外抗氧化活性,并分析了益智总黄酮含量与其抗氧化活性的相关性.结果表明,益智总黄酮超声辅助提取最佳工艺为:甲醇浓度100％,超声时间20 min,液料比25:1(mL/g),该条件下益智总黄酮提取率达0.757％.益智体外具有较强的抗氧化活性,其清除DPPH自由基、ABTS自由基的IC50值分别在0.851～3.188 mg/mL(相当于生药)、0.642～1.789 mg/mL(相当于生药)之间,FRAP值在0.029～0.111 mmol/L之间,总黄酮含量与清除DPPH自由基的IC50值和总抗氧化能力FRAP值呈显著相关(P<0.05),但与清除ABTS自由基IC50值相关性不显著.     

红树莓花青素的微波辅助提取研究

目的：红树莓花青素的微波辅助提取及其体外清除自由基能力。方法：花青素提取工艺采用中心试验设计响应面试验设计,抗氧化能力测定通过了清除羟自由基、ABTS和DPPH进行评判。结果：红树莓花青素的最佳提取工艺为：微波强度600W,微波时间40S,液料比60︰1,酸化乙醇浓度的体积比为20:80,浸泡时间10min。在此条件下树莓花青素的预测含量为0.055mg/g,实际测得花青素的含量为0.054mg/g。     

黑枸杞总黄酮微波辅助提取及其抗氧化活性研究

以总黄酮提取率为考察指标,通过单因素试验与正交试验,研究了影响黑枸杞总黄酮微波辅助提取的因素条件,优化了提取工艺,同时以2,6-二叔丁基对甲酚(BHT)为阳性对照,利用1,1-二苯基-2-三硝基苯肼自由基(DPPH·)与羟基自由基(·OH)清除法评价黑枸杞总黄酮的抗氧化活性。结果表明,乙醇浓度对黑枸杞总黄酮微波辅助提取有显著影响,黑枸杞总黄酮最佳提取工艺条件为:60%乙醇为提取剂,料液比1∶25(g/m L),微波时间14 min,微波功率325 W。该提取工艺条件下,黑枸杞总黄酮提取率为4.35%。黑枸杞总黄酮与BHT对DPPH·的IC50分别为0.64 mg/m L和1.30 mg/m L,对·OH的IC50分别为0.40 mg/m L和1.68 mg/m L,表明黑枸杞总黄酮具有很强的抗氧化活性。     

藤三七总黄酮的超声波辅助提取及其抗氧化性研究

以藤三七为原料,采用超声波辅助提取总黄酮,利用正交试验优化其提取工艺,并从清除羟基自由基(·OH)、1,1-苯基-2-苦基肼自由基(DPPH·)和超氧阴离子自由基(O2-·)的能力3个角度评价其抗氧化性。结果表明,超声波辅助提取藤三七总黄酮的最佳提取工艺为:乙醇体积分数80%,液料比40∶1(m L/g),超声时间60 min,超声温度40℃。在该条件下,总黄酮平均提取率为18.51%。超声波辅助提取的总黄酮具有较强的抗氧化性,对·OH、DPPH·、O2-·清除作用明显,且其质量浓度与抗氧化活性呈量效关系,是一种良好的天然抗氧化剂。     

菌草灵芝多糖提取工艺优化及抗氧化活性研究

在单因素试验的基础上,利用正交试验对菌草灵芝多糖的提取工艺条件进行优化,同时通过对DPPH自由基、羟自由基的清除能力和还原力对其抗氧化活性进行评价。结果表明,菌草灵芝多糖的最佳提取工艺条件为提取时间2.5 h,提取温度95℃,料液比1∶25(g∶g);在该条件下提取率为1.65%。抗氧化试验结果表明,菌草灵芝多糖对DPPH自由基和羟自由基有一定的清除能力,且与多糖质量浓度存在一定的量效关系,表明菌草灵芝多糖是一种潜在的抗氧化剂。     

超声联合酶法提取紫花苜蓿总黄酮及其抗氧化性能研究

采用超声联合酶法提取紫花苜蓿总黄酮,利用响应面法对该提取工艺进行优化,并对其提取物进行体外抗氧化活性研究。结果表明,超声联合酶法提取紫花苜蓿总黄酮的最佳工艺为:液料比40:1,超声时间为55min,超声温度为60℃,在此条件下紫花苜蓿总黄酮的提取率达9.928mg/g,与理论值的相对误差为0.40%,相比于其他传统方法,提取量大大提高;此外,紫花苜蓿总黄酮拥有良好的清除DPPH和·OH自由基的能力,其半数清除浓度(IC50)分别为14.31μg/mL及28.23μg/mL。     

空心菜总黄酮的超声波辅助提取及其抗氧化活性研究

以干燥空心菜茎叶粉为原料,在单因素试验的基础上,通过正交试验对乙醇超声辅助提取空心菜中总黄酮的工艺进行优化,并研究了空心菜总黄酮的体外抗氧化活性。结果表明,空心菜中总黄酮最佳提取工艺条件为:提取温度65℃,乙醇体积分数70%,固液比1∶20(g/m L),超声提取时间35 min,该优化条件下,空心菜中总黄酮的得率为29.39 mg/g。空心菜总黄酮对铁离子有较强的还原能力,对羟基自由基具有明显的清除力,且空心菜总黄酮的抗氧化作用随浓度增大而增强,但其抗氧化能力弱于VC。     

乙醇回流法提取甜菜树总黄酮及其抗氧化性评价

以甜菜树为原料,总黄酮提取率为考察指标,在单因素试验的基础上,通过正交试验优化乙醇回流法提取总黄酮的最佳工艺条件,并就总黄酮对1,1-二苯基-2-苦基肼自由基(DPPH·)、羟基自由基(·OH)和超氧阴离子自由基(O2-·)的清除作用进行了初步研究。结果表明,甜菜树总黄酮最佳提取工艺参数为:乙醇体积分数85%,料液比1∶40(g/m L),提取温度80℃,提取时间180 min,在该提取工艺条件下,得到甜菜树总黄酮平均提取率为1.67%。总黄酮质量浓度在0.009 3~0.046 5 mg/m L时,对DPPH·、·OH、O2-·的清除率可分别达到88.39%、91.47%、46.29%,说明甜菜树总黄酮具有较强的体外抗氧化活性。     

枇杷叶总黄酮超高压提取及抗氧化活性

为研究超高压提取的枇杷叶总黄酮的抗氧化能力。选用L9(34) 正交实验对枇杷叶总黄酮的提取工艺条件进行优选,以总黄酮得率为指标,考察乙醇浓度、超高压压力、超高压提取时间、固液比(g：mL)对总黄酮得率的影响。并且测定了总黄酮对DPPH自由基的清除作用。结果表明：总黄酮提取最佳工艺条件为：乙醇浓度50%、超高压压力400Mpa、超高压提取时间4.5min、固液比1：18。该条件下总黄酮的得率可达0.693%,总黄酮浓度和对DPPH自由基的清除作用呈现线性相关。超高压提取的总黄酮具有较强的抗氧化能力,具有较高的应用价值。     

微波辅助提取石榴皮黄酮及抗氧化活性研究

以石榴皮为原料,在单因素试验的基础上,采用响应面法优化石榴皮中黄酮化合物的微波辅助提取工艺,并就其对1,1-二苯基-2-三硝基苯肼自由基(DPPH·)清除能力进行探讨。结果表明,石榴皮黄酮化合物的微波辅助提取最佳工艺条件为:乙醇浓度60%,液料比40∶1(m L/g),微波提取时间2.70min,该条件下黄酮提取率的平均值为(4.424±0.168)%,与模型预测的黄酮提取率4.523%相近。制得的石榴皮提取物对DPPH·清除试验的IC_(50)为0.187 mg/m L,说明其具有较强的抗氧化活性。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

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.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

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.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

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.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

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.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

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.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

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).     

Screening techniques and sources of resistance to parasitic angiosperms

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.