利用SSR引物通用性分析杨柳科树种遗传多样性

利用SSR引物的种间通用性,本研究分别从杨属和柳属中各随机筛选出10对SSR引物,对17个杨树品种和20个柳树品种的遗传关系进行了分析。结果表明,18对引物在杨树品种有扩增,共扩增出155条多态性谱带,多态性比率为93.4%,平均每对引物扩增出8.6条谱带;16对引物对在柳树品种有扩增,共扩增出120条多态性谱带,多态性比率为91.6%,平均每对引物扩增出7.5条谱带。筛选出了14对杨柳树通用引物,14对通用引物可以将37个供试材料分成两大类,一类为杨树树种,一类为柳树树种,与传统的植物学分类相符。     

应用ISSR分子标记绘制红麻种质资源DNA指纹图谱

以6份红麻种质资源为材料, 对UBC807~UBC80等80个ISSR引物进行筛选, 筛选出多态性好的ISSR引物20个。利用这20个ISSR引物扩增来自国内外84份红麻种质资源, 共获得230条谱带, 平均每个引物扩增出11.5条谱带, 其中多态性谱带185条, 多态性条带比率为80.43%, 表明供试的红麻种质资源遗传多样性较丰富。以供试84份红麻种质资源的ISSR扩增谱带为基础, 建立了供试材料扩增条带指纹数据库的Excel文件。根据指纹图谱唯一性原则, 采用自行开发的DNA指纹数据分析软件, 再从20个多态性好的ISSR引物中遴选出UBC 813、UBC 825、UBC 836、UBC 888和UBC 889引物, 绘制出82个红麻种质资源的DNA指纹图谱, 为红麻种质资源分子身份证的构建奠定了基础。     

基于RAPD标记的芥蓝种质资源遗传多样性分析

调查了44份芥蓝种质的植物学性状,并利用RAPD分子标记分析了其遗传多样性。结果从150条随机引物中筛选出20个引物,20个引物共扩增出177条谱带,其中多态谱带105条,平均每个引物扩增出8.9条谱带和5.3条多态性谱,多态性比率为59.32%。基于RAPD标记,利用NTSYS-pc2.11构建了聚类树状图谱,遗传距离为0.70时,44份芥蓝资源可聚成六大类群。芥蓝种质存在着一定的遗传多样性,但原产华南而且主要产区也在华南,遗传多样性要小于芸薹属其他蔬菜。     

中国江、浙地区栽培大麦遗传资源的RAPD研究

采用随机扩增多态性（RAPD）标记，探讨了我国部分栽培大麦品种的遗传背景。结果表明：200个随机引物中，有30个引物扩增出的产物具有多态性，30个引物共扩增出223条谱带，其中130条谱带具有多态性，每个引物可扩增出2~9条多态性谱带，平均4.19条。67个大麦品种平均表型多样性值0.369，裸麦的表型多样性高于皮麦的表型多样性     

滩地13个杨树无性系遗传多样性的RAPD分析

利用RAPD分子标记手段,研究杨树无性系的遗传多样性。在探讨杨树叶片基因组DNA提纯方法和优化PCR扩增反应体系的基础上,采用18个引物对13个杨树无性系的基因组DNA进行扩增;每个引物扩增的DNA片段数为1~14个,共产生126条带,其中多态带53条,占42%,平均每个引物扩增出3条多态带。结果表明：通过对126条谱带的聚类,分析了供试杨树无性系的系统发育,并通过比较各品种间的特异带或特征带的差异进行无性系鉴别和测定,运用特殊谱带,建立了杨树无性系的分子检索表。     

AFLP分子标记鉴别大白菜品种

本试验采用AFLP技术,研究了90份来自7个不同栽培地区的大白菜品种材料。共筛选了20对引物,不同引物组合检测多态性谱带的能力有很大的差异,多态性谱带的数量从9条到32条不等。其中E—ACA／M—CTG是大白菜品种十分高效的引物组合,共产生7l条清晰的扩增带,其中有32条多态性谱带,多态性谱带的百分率为45．7％。通过该引物组合,能将90个品种全部区分开来。同时应用该引物组合检测2个大白菜杂交品种(北京新2号,京夏王)各10株,其中有1株北京新2号的谱带异常,其余同一品种不同单株的带型完全一致。表明AFLP标记用于研究品种指纹图谱,并鉴别品种是完全可行的。     

不同品种绵羊杂交后代RAPD的分析

对3个不同绵羊类群(无角道塞特二代公羊、杜泊一代公羊、杜泊二代公羊)共8个样本应用20个随机引物扩增进行RAPD分析。结果表明,在20个随机引物中,有7个随机引物扩增出不同程度的清晰可辨的RAPD谱带,其中标记总数为35条,多态标记数为24条。共得到147条清晰的谱带。杜泊一代与杜泊二代2个种群间遗传距离最小,为0.080 9;杜泊一代与无角道塞特2个种群间遗传距离最大,为0.515 2。     

广西藤县大果红山茶种质资源的遗传多样性分析

为了分析广西藤县大果红山茶的遗传多样性,应用分子标记技术对14个大果红山茶样本进行标记,并利用NTSYSpc 2.1软件对分子标记结果进行聚类分析。结果表明:5条引物对14份供试样本的DNA进行扩增检验,共扩增出38条谱带,其中多态性谱带37条,多态性比率为97.37%;14株样本间遗传距离为0.3952~2.1383,其中3-5号和1-12号的遗传距离最大,为2.1383;而N3号和JJ5号的遗传距离最小,为0.3952;说明大果红山茶种间的遗传多样性较高,遗传分化较显著。     

适于百合遗传多样性分析的RAPD引物筛选

为筛选出适于百合遗传多样性分析的RAPD有效引物,利用48个RAPD随机引物,对百合属的黄天霸、西伯利亚、兰州百合和川百合进行PCR扩增,共筛选出8条多态性丰富、条带清晰且可重复性好的有效引物,8条引物在4个样品中共扩增出112条DNA带,其中78条为多态性带,占总扩增带数的69.6%,平均每个引物扩增出14条带。该研究为应用RAPD标记技术进行百合属植物遗传多样性分析和品种分子鉴别等研究奠定了基础。     

茶树种质资源遗传多样性的RAPD分析

用随机扩增多态DNA（RAPD）标记对来自全国产茶省的31份种质资源、福建地区的10份种质资源以及湖南安化云台山种有性后代居群的30个单株的遗传多样性进行了检测。不同生态条件下的31份不同种质资源中,21个RAPD引物扩增出188条谱带,多态性比率为90.43%;福建10份种质资源,21个RAPD引物共扩增出154条谱带,多态性比率为81.81     

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...     

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.