马铃薯种质遗传多样性分析的AFLP反应体系优化与引物筛选

本试验主要对AFLP反应体系进行优化,并用该体系筛选适用于马铃薯种质资源遗传多样性分析的引物。酶切连接、预扩增和选择性扩增体系的优化结果表明,建立的马铃薯AFLP反应体系为:模板DNA160ng,37℃酶切连接12h;预扩增体系中dNTP浓度为0.2mmol/L,TaqDNA聚合酶用量为1U;选择性扩增体系中预扩增产物稀释20倍,引物终浓度为2.5ng/μL。利用优化后的AFLP反应体系,以5个马铃薯品种为试材筛选选择性引物,可以从81对引物组合中选出16对条带丰富且多态性较高的引物组合。本研究为种质资源鉴定、马铃薯遗传多样性以及马铃薯抗病性研究等奠定了良好的基础。     

大麻基因组DNA提取及AFLP体系的建立

本研究以大麻嫩叶为材料,以改进的SDS法,提取了高质量的大麻基因组DNA,经过酶切、连接、预扩增、选择性扩增、银染等试验条件的优化,建立了AFLP反应体系。研究结果表明:在常规的SDS提取液里加入8μL/mLβ-巯基乙醇(V/V)和3%PVP(M/V)能够提取到高质量的适用于AFLP的基因组DNA;选取150ng大麻基因组DNA来进行酶切,EcoRⅠ和MseⅠ各0.5U,在37℃酶切4h,即可完全酶切。最优的选择性扩增体系为20μL反应体系中含有1.0U Taq DNA polymerase、1.0μL25mmol/L Mg2+、0.4μL10mmol/LdNTPs、50ng/μL引物各1.0μL、4.0μL稀释50倍的预扩增产物及2μL10×PCR Buffer;使用该方法,获得了清晰、稳定的图谱并筛选到了18对多态性较好的AFLP引物组合。     

独脚金AFLP反应体系的优化及引物筛选

为了构建一套适合中国独脚金种质资源的AFLP反应体系,本研究以独脚金幼嫩茎叶为材料,对影响AFLP反应体系的酶切连接反应、预扩增和选择性扩增过程中的一些关键因素进行优化,并利用优化的反应体系对AFLP引物进行筛选。结果表明,最佳的酶切反应体系为DNA模板200 ng,MseⅠ/EcoRⅠ用量3 U,总体积20μL,37℃酶切反应时间3 h,72℃灭活20 min;最佳连接反应体系为T4连接酶5 U,16℃连接过夜;最佳预扩增反应体系为dNTP浓度0.2 mmol/L,Taq DNA聚合酶浓度2 U,总体积25μL;选择性扩增的反应体系为d NTP浓度0.2 mmol/L,Taq DNA聚合酶浓度1 U,预扩增产物稀释5～10倍,总体积10μL。采用优化的AFLP反应体系,对来自3个不同来源地的独脚金样本进行选择性扩增,100对引物组合均能扩增出清晰、丰富的条带,且在参试样本中均能表现出一定的扩增多态性。本研究筛选出的引物组合可用于后续独脚金种质资源遗传多样性的研究,为独脚金遗传多样性研究、种质资源保存和鉴定提供一定的参考。     

甘肃金鳟AFLP体系建立及应用

甘肃金鳟是我国自主培育的虹鳟新品种,为进行其种质资源研究和遗传管理,以其尾鳍为试验材料,提取基因组DNA,对影响甘肃金鳟扩增片断长度多态性(AFLP)反应体系进行优化,包括模板DNA浓度、基因组酶切时间、选择性扩增中Mg2+、预扩增产物稀释倍数及选扩性引物M+3/E+3配比等进行比较分析,建立了适于甘肃金鳟的AFLP反应体系。即：100 ng 基因组DNA,3 U EcoR I 37℃酶切3 h,再 Mse I 65℃酶切5 h;然后用1 U的T4连接酶连接12 h, 选扩25 μl PCR反应体系中Mg2+2.0 mmol/L,预扩产物稀释30倍,选扩引物M+3/E+3配比为8∶1,所得产物经电泳和银染后可获得清晰条带,效果良好;筛选出了适宜甘肃金鳟品种分析的13对选择性引物。     

甘薯AFLP分子标记体系建立

AFLP是目前最常用的几种标记之一。本文以甘薯为材料,通过DNA提取、酶切、PCR扩增、凝胶电泳等系列程序摸索和优化,建立了甘薯的AFLP分子标记体系。优化的甘薯AFLP分子标记体系的程序如下:将4μl100ng/μl的甘薯DNA用EcoRⅠ酶、MseⅠ酶各5U进行双酶切,在37℃下酶切3h后再在65℃下酶切3h;然后加入10μl连接混合液在22℃下连接3h后在16℃下连接10h;取连接产物5μl,10μmol/LEcoRⅠ预扩引物和10μmol/LMseⅠ预扩引物各1.5μl,PCR缓冲液25μl,ddH2O17μl进行预扩增;取5μl稀释20倍后的预扩增产物,50ng/μlEcoRⅠ选扩引物和50ng/μlMseⅠ选扩引物各1μl,PCR缓冲液10μl,ddH2O3μl,进行选择性扩增。本研究为甘薯黑斑病和其他真菌性病害的分子标记克隆及抗病育种的辅助选择提供了有力工具。     

菠菜AFLP反应体系初探

提取菠菜嫩叶DNA,运用改良CTAB法提取6份菠菜品种的DNA,对AFLP反应体系的DNA用量、酶切连接、预扩、选扩等试验条件进行了优化分析,初步建立适合于菠菜作物的AFLP反应体系.结果表明:①在PCR仪中酶切的效果比水浴的要好,酶切反应对酶切时间和DNA的浓度要求不敏感.②菠菜AFLP预扩选扩体系的反应体积为20 μL,Mg2+ (25 mmol/L) 1.2 μL,dNTPs (2.5 mmol/L) 1.6 μL,Taq-polymerase (5 U/μL) 0.2 μL最佳.为菠菜AFLP分子标记的品种亲缘关系鉴定和遗传育种等提供一定的理论基础.     

小麦锈菌AFLP分子标记技术体系的建立

以小麦条锈菌、杆锈菌、叶锈菌的夏孢子为材料,通过DNA提取、酶切、PCR扩增、凝胶电泳等系列程序摸索和优化,建立了锈菌的AFLP分子标记体系如下： 40μl酶切体系中采用了EcoRI、TrulI各5U,37℃3h,65℃3h双酶切4μl 100ng/μl的DNA; 然后加入10μl连接混合液22℃连接3h,16℃10h; 连接产物5μl,10μMEcoRI、10μMTru1I预扩引物各1.5μl,PCR反应液25μl,ddH2O 17μl进行预扩;预扩产物稀释20倍后取5μl,50ng/μl EcoRI、Tru1I选扩引物各1μl,PCR反应液10μl,ddH2O 3μl体系进行选择性扩增,为小麦锈病和其他真菌性病害的分子标记克隆及抗病育种的辅助选择提供了有力工具。     

水稻叶片cDNA-AFLP技术体系的建立和优化

以高温和常温处理的水稻幼苗叶片为材料,对影响cDNA-AFLP分析体系的关键因素进行了分析,建立了适宜水稻的cDNA-AFLP分析体系,并得到了清晰可辨的cDNA-AFLP指纹图谱。结果表明:离心柱式试剂盒提取的RNA较完整,纯度较高;双链逆转录试剂盒形成的cDNA经EcoRⅠ(37℃,2 h)和MseⅠ(65℃,2 h)完全酶切后,4℃连接过夜;20μL的体系中,连接产物稀释10倍液5.0μL作为预扩增的模板,并且预扩增反应的循环数为35,预扩增产物稀释20倍作为选择性扩增的模板,扩增结果较佳;6%PAGE分离快速银染法显示,64对选择性扩增引物中筛选出多态生条带丰富的AFLP引物50对。本研究为利用cDNA-AFLP分析水稻抗高温基因进行深入的研究奠定了基础。     

蓖麻标雌/单雌/两性系花序MSAP反应体系的建立

为了建立Lm型雌性系蓖麻不同发育时期的标雌/单雌/两性系花序MSAP反应体系,提取不同类型不同发育时期的花序基因组DNA,混合成基因池;用EcoRⅠ和HpaⅡ/MspⅠ的组合,12 h可将DNA酶切完全;16℃条件下,将酶切产物与EcoRⅠ、HpaⅡ/MspⅠ接头过夜连接;连接产物用于预扩增。优化后的预扩增反应体系为10×PCR Buffer 2.5μL、d NTPs(10 mmol/L)2.5μL、Mg2+(25 mmol/L)2.0μL、模板2.0μL、E0扩增引物(10pmol/μL)1.5μL、H0扩增引物(10 pmol/μL)1.5μL、LA Taq(5 U/μL)0.25μL、dd H2O 12.75μL。预扩增产物稀释10倍后用于选择性扩增。优化后的选择性扩增体系为10×PCR Buffer 2.5μL、d NTPs(10 mmol/L)2.0μL、Mg2+(25mmol/L)4.0μL、模板3.0μL、EX扩增引物(10 pmol/μL)1.0μL、H/MX扩增引物(10 pmol/μL)1.0μL、LA Taq(5U/μL)0.30μL、dd H2O 11.2μL。     

芒属植物AFLP分析体系的建立与优化

对AFLP实验流程中的基因组提取、酶切等关键因素进行优化,建立了芒属植物的AFLP(扩增片段长度多态性)分析体系。本研究分别采用常规CTAB法和改良的CTAB法提取芒属植物基因组DNA,基因组分别用HindⅢ/MseⅠ系统和PstⅠ/MseⅠ系统进行酶切和连接一步反应,连接产物稀释20倍后进行预扩增,预扩产物稀释20倍后进行选择性扩增。结果显示:采用改良CTAB法提取的DNA质量优于常规CTAB法;采用PstⅠ/MseⅠ系统酶切的DNA多态性高于HindⅢ/MseⅠ系统。采用优化后的AFLP体系分析30份供试芒属植物材料,从64对引物中筛选出8对多态性较好的AFLP选择性扩增引物,多态性比率达到100%,表明优化后的AFLP体系适合于芒属植物的分子标记分析,为芒属植物种质遗传多样性的分子研究奠定了技术基础。     

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.