葡萄5BB品种SRAP-PCR反应体系影响因素

为建立适合葡萄5BB品种的SRAP-PCR反应体系,利用正交设计对葡萄SRAP-PCR反应体系5种因素(Taq DNA聚合酶,Mg2+,模板DNA,dNTP,引物)4个水平进行优化。结果表明,各因素水平变化对PCR反应的影响从大到小顺序为:Mg2+,引物,dNTP,Taq DNA聚合酶,模板DNA;筛选出各因素的最佳水平,建立了葡萄5BB品种SRAP-PCR反应的最佳体系(20μL)为:Taq DNA聚合酶2U,Mg2+2.0mmol/L,模板DNA60ng,dNTP0.25mmol/L,引物0.10μmol/L。这一优化系统的建立为今后利用SRAP标记技术对葡萄进行相关研究提供了帮助。     

柑桔SRAP和ISSR分子标记技术体系的建立与优化

通过对PCR反应程序、反应体系(DNA模板量、PCR反应体积、Mg2 浓度、dNTP浓度、Taq酶用量、引物量)、电泳检测方法的系统优化,建立了柑桔SRAP-PCR和ISSR-PCR体系;以此进行大规模引物筛选,从而建立了柑桔SRAP和ISSR分子标记技术体系.SRAP-PCR:25μL体系,模板DNA25ng,Tris-HCl10 mmol/L,KCl50 mmol/L,Mg2 1.2 mmol/L,dNTP 120 μmol/L,Taq酶1.5U,引物0.4μmol/L,反应程序为94℃预变性5min,35个循环(94℃ 30s,47℃ 1min,72℃ 1min),72℃延伸10min;ISSR-PCR:25μL体系,模板DNA25ng,Tris-HCl10mmol/L,KCl50mmol/L,Mg2 1.6 mmol/L,dNTP200μmol/L,Taq酶1 U,引物0.8μmol/L.筛选出稳定性好、多态性高的24对SRAP引物和13条ISSR引物.     

应用正交设计建立芍药的SRAP反应体系

为快速建立优化的芍药SRAP扩增反应体系,应用L25(56)正交表,研究了Taq、Mg2+、随机引物、dNTPs和DNA模板5种反应组分的浓度变化对SRAP扩增结果的影响,直观分析和稳定性检测结果表明:正交设计可高效建立优化稳定的芍药SRAP反应体系;用该法建立的芍药SRAP-PCR优化反应体系为:25μL反应体系中含10×PCR Buffer(100 mmol/L Tris-HCl pH 8.3,500 mmol/L KCl)2.5μL,MgCl22.5 mmol/L,dNTP各0.25 mmol/L,引物各0.3μmol/L,TaqDNA聚合酶1 U,DNA模板120 ng。     

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.     

石斛属植物ISSR扩增体系的建立与优化

旨在建立并优化石斛属植物的ISSR-PCR反应体系。通过对ISSR-PCR反应体系中主要影响因子模板DNA、dNTP、10×PCR Buffer、引物以及Taq DNA聚合酶分别进行单因素优化,最终建立一套适用于石斛属植物的扩增多态性高、稳定性强、带型清晰的ISSR最佳反应体系。20μL反应体系的适宜浓度及用量分别为：模板DNA 10 ng/μL 3μL,dNTP 2.5 mmol/L 1.5μL,10×PCR Buffer 3.0μL,引物4μmol/L 3.5μL,TaqDNA聚合酶5 U 0.2μL。这一优化体系适用于石斛ISSR分析,为今后遗传多样性与亲缘关系分析、连锁图谱构建、QTL定位、基因定位与克隆等方面的研究提供了技术支撑。     

仙茅属植物SRAP-PCR反应体系的优化

通过单因子和双因子实验对仙茅属植物SRAP-PCR反应体系中主要成分(Mg2 、dNTP、引物、模板和Taq DNA聚合酶)进行优化,并比较了琼脂糖凝胶电泳与非变性PAGE电泳的检测效果.建立了适合仙茅属植物SRAP分析的反应体系:25 μL体系中内含1×PCR buffer、2.0 mmol/L Mg2 、250 μmol/L dNTP、0.2 μmol/L引物、40 ng模板、1 U Taq酶.非变性聚丙烯酰胺凝胶电泳分辨率较高且带型清晰,能更准确反映仙茅属植物间的差异.优化的反应体系可以用于仙茅属植物的SRAP分析.     

大豆SSR技术反应体系的优化

以大豆为材料,研究了PCR反应体系的主要成分模板DNA浓度、dNTP浓度、引物浓度、Taq酶浓度及退火温度对大豆SSR扩增结果的影响,探索影响SSR扩增结果的各因素的最佳用量及引物的退火温度。结果表明:在试验设计范围内,DNA浓度和dNTP浓度对扩增影响较大,引物浓度在0.05~0.2μmol/L范围内对扩增影响较小,Taq酶浓度对扩增有一定影响,引物要有其扩增适宜的退火温度。确立了适合大豆SSR分子标记研究的优化体系。最终确定总反应体系为20μL,模板DNA 20 ng,dNTP 200μmol/L,引物0.15μmol/L,Taq酶0.5 U,10×Taq Buffer 1.5 mmol/L,ddH2O补至20μL。     

花生SRAP-PCR反应体系的正交设计优化

本研究利用正交设计L16(45)对花生SRAP-PCR反应体系的5因素(引物,Taq酶,Mg2+,模板DNA和dNTP)在4水平上进行优化试验,结果表明,各因素的不同水平对PCR反应结果都有显著的影响,其中引物浓度的影响最大;最佳反应体系20μL包含:引物0.4μmol/L,Taq酶1U,Mg2+2.5mmol/L,模板DNA30ng,dNTP0.2mmol/L,不足部分以ddH2O补足。这一体系的建立为今后利用SRAP标记技术对花生进行分子遗传学基础研究提供了有力的支持。     

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。     

番石榴SRAP反应体系的建立与正交优化

采用正交设计方法,对影响番石榴SRAP反应体系的Mg2+、dNTPs、引物、Taq DNA聚合酶和模板DNA浓度等进行了优化,建立了适用于番石榴的SRAP反应体系。该优化的20 μL反应体系中包含2.5 mmol/L Mg2+,0.15 mmol/L dNTPs,0.4 μmol/L引物,1.5 U Taq DNA聚合酶和20 ng模板DNA。利用该优化体系通过64对SRAP引物组合对5份番石榴材料进行了SRAP-PCR扩增,结果表明SRAP引物及优化后的反应体系能够有效地用于番石榴种质资源鉴定及遗传多样性分析等研究。     

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.     

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.     

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.     

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...     

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.     

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.     

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.