月季SSR-PCR反应体系的建立和优化

采用L16(54)正交设计和二因素完全随机试验,分析了月季SSR-PCR反应体系的主要成分Taq DNA聚合酶、样本浓度、Mg2+浓度、dNTP浓度以及引物浓度对扩增结果的影响,建立了适合月季的SSR反应体系.研究结果表明:在20μL反应体系中,Taq DNA聚合酶宜加入1.5U,样本最适宜浓度为30～40 ng,Mg2+的最适浓度为1～1.5 mmol/L,dNTP最适浓度为0.2 mmol/L,单引物的最适浓度均为1μmol/L.用建成的反应体系对19对引物筛选,对12个月季品种扩增,3%的琼脂糖凝胶电泳检测,品种间DNA谱带多态性丰富,证明该体系稳定可靠.     

正交设计优化青蒿SRAP-PCR反应体系及引物筛选

为了建立青蒿的SRAP最佳扩增体系,并筛选出SRAP多态性引物,本研究以青蒿叶片DNA为模板,采用正交试验设计,以Mg^2+、dNTP Mix、Taq DNA聚合酶、引物和DNA模板5种因素5个水平,对青蒿SRAP反应体系进行研究。结果表明,青蒿SRAP-PCR最佳反应体系为:引物0.6μmol/L、Mg^2+2.0 mmol/L、模板DNA 5.1 ng、Taq DNA聚合酶2.0 U、dNTPs 0.25 mmol/L,总体积为25μL。各因素对扩增反应均有不同影响,其中引物浓度的影响最大,dNTPs的影响最小。运用该体系对不同种质资源的青蒿进行验证,证明该体系稳定可靠,并在30个引物组合中筛选出了25对扩增条带清晰,多态性丰富的引物组合。这一结论为今后利用SRAP标记技术进行青蒿分子遗传学研究提供了科学依据。     

叶用莴苣TRAP 反应体系的建立

以叶用莴苣为试材,采用正交设计和单因素试验2种方法研究叶用莴苣TRAP反应体系中Mg^2＋、Taq DNA聚合酶、dNTPs、引物等4个因素的浓度变化对扩增结果的影响,建立最佳反应体系。结果表明：TRAP-PCR反应最优体系是在20μL反应体系中含DNA模板60～100 ng、10×PCR buffer（Mg^2＋free）2μL、Mg^2＋终浓度2.0 mmol/L、Taq DNA聚合酶含量1.0 U、dNTPs终浓度0.2 mmol/L、引物终浓度0.75μmol/L。该体系对叶用莴苣种质的扩增结果稳定,条带清晰度高且多态性丰富,可用于对叶用莴苣种质资源的遗传多样性分析和亲缘关系鉴定。     

水稻TRAP-PCR反应体系优化与P-糖蛋白基因片段的分析

对影响TRAP-PCR反应体系的各参数,包括模板DNA、dNTP、Taq DNA聚合酶和引物浓度进行了优化,建立了适合水稻的稳定,可重复的TRAP-PCR反应体系.在20μL PCR反应体系中,含80 ng模板DNA,0.25 mmol/L dNTP,0.75 U Taq DNA聚合酶,5 ng/μL随机引物和7.5 ng/μL特异引物.本研究对P-糖蛋白基因片段进行了克隆并序列分析,为深一步研究奠定了基础.     

淮山RAPD-PCR反应体系的建立

摘要：采用改良CTAB法提取淮山的叶片总DNA。通过单因子实验法分析DNA浓度、引物浓度、dNTP浓度、Taq聚合酶以及Mg2+浓度对RAPD-PCR扩增结果的影响,建立了适合于淮山RAPD-PCR反应体系,即20μL体系中包括：模板DNA为50 ng、Taq酶为0.2U、Mg2+浓度为3.0mmol/L、引物浓度为0.2μmol/L、dNTPs浓度为0.2mmol/L。     

利用正交设计优化水曲柳ISSR-PCR反应体系

利用正交设计L16(4^5）对水曲柳ISSR-PCR反应体系的5因素(Taq酶,Mg^2 ,模板DNA,dNTP,引物)在4个水平上进行优化试验,PCR结果用统计软件MINITAB分析：①各因素的不同水平对PCR反应结果都有显著的影响,其中Taq酶量影响最大;②筛选出各反应因素的最佳水平,建立水曲柳ISSR-PCR反应的最佳体系(20μl)为：Taq酶1．0U,Mg^2 2．0mmol/L,模板DNA50-200ng,dNTP0．15mmol/L,引物0．31μmol／L。最后,对水曲柳ISSR-PCR最佳反应体系进行梯度退火,得到最佳退火温度为58．3℃。这一优化系统的建立为今后利用ISSR标记技术,研究水曲柳的地理变异提供一个标准化程序。     

新疆贝母DNA提取及ISSR-PCR体系的建立与优化

目的:从新疆贝母干叶片中提取高质量的DNA,建立ISSR-PCR体系并进行优化。方法:通过改进的CTAB法提取基因组DNA;综合利用单因素实验和L9(34)正交实验2种方法,对镁离子、dNTP、模板DNA含量、TaqDNA聚合酶量、引物浓度等因素进行优化,并采用温度梯度筛选引物的退火温度。结果:新疆贝母20μL ISSR-PCR最适反应体系dNTP为0.3 mmol/L,Mg2+为2.0 mmol/L,模板浓度为40～100 ng/(20μL),引物为1.2 mmol/L,Taq DNA聚合酶为1.0 U/20μL,引物UBC 859的最适退火温度为50.7℃。结论:此提取方法得到的DNA纯度高,ISSR-PCR扩增效果显著,为新疆贝母种质资源鉴定、遗传多样性分析奠定研究基础。     

苦瓜ISSR-CR反应体系的建立

以苦瓜（Momordica charantia L．）为试材，研究了PCR反应体系的主要成分及退火温度、循环次数对苦瓜ISSR扩增结果的影响。结果表明：在20μl的反应体系中，Mg^2＋的用量为1．2—1．6mmol／L，dNTPs浓度为0．2mmol／L，引物的浓度为0．25μmol／L，Taq DNA聚合酶的用量为1u，模板DNA的用量为30～50ng，在46．4—51.7℃的退火温度下35个循环，能得到清晰、多态性高的ISSR带谱。     

两种方法对广玉兰ISSR-PCR反应体系的优化比较

采用单因子和正交设计2种方法,对影响广玉兰ISSR-PCR反应体系的5个因素（Taq酶、Mg^2＋、dNTP、引模板DNA）进行优化。结果表明：正交设计采用直观分析法获得影响因素最佳反应水平与单因子试验找出影响因素最佳反应水平有一定差异,通过综合比较分析,最终建立了广玉兰ISSR．PCR的最佳反应体系：在20μl的反应体系中,TaqDNA聚合酶1．0U、Mg^2＋1．2—1．5mmoL／L、dNTP1．80mmoL／L、引物0．5—0．6μmoL／L、30ng模板DNA、10×PCR buffer。同时,通过PCR比较,确定延伸时间为2min,循环次数为35个较为合适,确定了引物最佳退火温度,得到了广玉兰ISSR—PCR反应的最佳扩增程序。     

软枣猕猴桃RAPD分子标记反应体系的优化

以长白山地区及韩国等9个采样点采集的软枣猕猴桃新鲜幼叶为试材,进行RAPD分子标记反应扩增体系的优化。对实验结果影响较大的5个因素(模板DNA浓度,引物浓度, MgCl_2浓度, dNTP浓度, Taq DNA聚合酶浓度)进行单因素设计,以寻找最佳反应浓度。结果表明,总反应体积为20μL时,模板DNA 40 ng、引物浓度0.3μmol/L、MgCl_2浓度2.0 mmol/L、dNTP浓度250μmol/L、Taq DNA聚合酶2.0 U。此时扩增条带多、电泳结果清晰稳定,表明该体系是一个适合软枣猕猴桃RAPD分子标记反应的体系。该体系的建立有利于软枣猕猴桃的亲缘关系和遗传多样性分析。     

pH敏感性离子凝胶/静电纺丝复合材料的制备及应用

食品营养和功效成分的稳态化技术是食品营养研究的热点之一,离子凝胶化是一种常用的制备酸度敏感性材料的方法,静电纺丝是一种制作纳米纤维的技术,这2种技术的结合有助于改善复合纳米材料的运载性能。介绍了pH敏感性离子凝胶化技术、静电纺丝技术及这2种技术的结合方面国内外最近研究进展,为离子凝胶/静电纺丝技术在食品稳态化技术应用方面提供技术参考。     

Identification of broad bean cultivars based on isozyme patterns

Summary With the increasing rate of new cultivar production for different crop plants, there is great need for methods of identifying each cultivar discriminatingly. Starch gel electrophoresis was employed to study the differences between the esterase and cathodal peroxidase isozyme patterns of 40 broad bean (Vicia faba L.) cultivars. A total of 10 and 17 medium to darkly stained bands were obtained for esterase and peroxidase systems, respectively. Bands from each enzyme system could be gropuped into three zones. Bands belonging to zone 1 of esterase (E₁) and zones 2 and 3 of peroxidase (P₂ and P₃) were quite distinct, stained intensely, and were especially useful for identification purposes.The differences in banding patterns among cultivars of the same origin were as great as those of cultivars of unrelated origin. A large proportion of the cultivars could be completely differentiated using both of the isozyme systems. There were no bands present in either enzyme system which were common to all cultivars.     

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...