马铃薯不同品种(系)遗传多样性的ISSR分析

本研究运用ISSR分子标记技术对30份马铃薯品种(系)材料进行多态性和聚类分析,分析各品种(系)间亲缘关系。结果表明:从56条ISSR引物中筛选出6条引物进行PCR扩增,共扩增出52条带,多态性条带为47个,多态性比率约为90.38%。通过UPGMA法对30份马铃薯品种(系)材料聚类分析显示,30份供试材料品种间遗传相似系数为0.40~0.95,平均相似系数为0.675;在相似性系数0.75附近,30份马铃薯品种(系)可分为6个大类,包括5大复合组和1个独立类。这些结果说明所选取的30个马铃薯品种(系)的遗传差异比较大,遗传多样性较丰富;该研究结果为马铃薯的遗传多样性利用及种质鉴定和杂交育种提供了有力的理论依据。     

俄罗斯马铃薯种质资源遗传多样性的SSR分析

俄罗斯马铃薯种质资源具有综合抗性强的特点。尤其适合东北三省及内蒙古东部地区种植。为了丰富中国马铃薯品种改良的基因资源,本试验选取54份俄罗斯血缘的马铃薯品种,利用SSR分子标记技术对其遗传多样性进行分析,从DNA分子水平上明确各品种间的遗传差异。本试验从50对SSR引物中筛选出14对多态性好,目的条带清晰的引物,对供试的54份品种进行PCR扩增,共扩增出229个多态性条带,多态性条带百分率到达92.7%。扩增片段在100~1 500 bp。其中引物STM0030可以将供试的54个品种全部区分开。遗传相似性系数的变幅为0.52~0.99,平均为0.68。经聚类分析,在遗传相似性系数0.756处,将供试品种分为10类,从分子水平上揭示了各供试品种间的亲缘关系。     

湖南省饭豆地方种质资源遗传多样性的RAPD和ISSR分析

为揭示湖南省饭豆地方品种的遗传多样性,促进种质资源的有效保护和利用。本研究利用RAPD和ISSR标记分析了源于湖南省各地36份古老饭豆地方品种的遗传多样性,并采用UPGMA方法进行了遗传聚类分析。结果表明：12个RAPD引物和4个ISSR引物在供试材料中共扩增产生81条带型清晰的条带,平均每个引物扩增产生5.06个条带;其中59个为多态性条带,占总扩增条带的72.84%,具有多态性引物的PIC值在0.397~0.968之间;通过UPGMA法进行聚类分析表明供试材料的遗传相似系数在0.605~0.877之间,供试材料被分为4大类,且聚类结果表现明显的地域特征。本研究结果可为本省饭豆种质资源保护和育种研究提供理论依据。     

东北地区部分马铃薯品种遗传多样性的SSR分析

为对东北地区马铃薯品种鉴定提供分子水平上的依据,选用部分主栽品种（系）18 份,利用筛选出的18对多态性较好的马铃薯SSR引物进行扩增,对供试材料进行遗传多样性分析并构建指纹图谱。结果表明,供试材料共扩增出156个等位位点,其中146个为多态性位点,多态性比率达92.4%,扩增产物片段在100~800bp。利用STM1021、STI051、S170、S7、STI030、STPATP1和STM2023这7对引物构建了供试品种（系）的SSR指纹图谱。其中引物S7可以将18份品种（系）完全区分开。经聚类分析,在遗传相似系数0.61处,所有供试材可明显分为2个类群,其中14个品种（系）聚在一类,表明,聚类分析结果与供试材料来源有较好的一致性。从分子水平上表明供试材料的遗传基础较狭窄。     

中国88个马铃薯审定品种SSR指纹图谱构建与遗传多样性分析

为对马铃薯品种鉴别、优良杂交组合选配提供分子水平上的依据,利用SSR标记构建了中国2000-2007年审定的88个马铃薯品种的指纹图谱并进行了遗传多样性分析。以138对SSR引物对16份遗传差异较大的马铃薯材料的基因组DNA进行了扩增,筛选出10对多态性高、谱带清晰的引物。利用10对SSR引物对全部供试材料进行扩增及电泳检测,共检测到135个等位位点,其中133个为多态性位点,多态性比率达98.52%。每对SSR引物扩增出的等位位点数7~22个,平均13.5个,多态性信息量变化范围为0.7604~0.9375,平均0.8501。通过对电泳检测结果的统计分析,利用S180、S25、S7、S151、S184及S192等6对引物构建了88份供试材料的SSR指纹图谱。聚类分析表明,在相似系数0.620处,所有供试材料被被聚为一类,在相似系数0.652处,81.8%的材料仍然聚在一起,从分子水平上表明供试材料遗传基础非常狭窄。聚类分析结果与供试材料系谱来源有较好一致性,同一栽培区域育成的品种在不同程度上聚在一类。     

贵州马铃薯引进品种SSR分子标记及遗传多样性分析

为了鉴定马铃薯品种间的亲缘关系,采用5对SSR分子标记引物,对18个贵州马铃薯生产品种进行SSR分子标记及遗传多样性分析.结果表明:5对SSR引物共扩增出77个多态性条带,每个组合的多态性条带数为10～24不等,平均每个引物组合产生15.4个多态性条带.18个马铃薯材料之间的遗传距离范围在0.376 6～0.909 0之间,平均为0.701 1.经聚类分析,18个马铃薯材料在遗传距离0.57水平上全部聚为一类,以遗传距离0.60为基准,可明显聚为4个类群.第Ⅰ类包括5个材料;第Ⅱ类仅1个材料;第Ⅲ类包括4个材料;第Ⅳ类包括8个材料.     

引进国外马铃薯种质资源的遗传多样性分析

应用RAPD标记技术研究国外马铃薯品种的遗传多样性,以期明确这些品种的亲缘关系,为马铃薯优良品种的选育提供理论依据。利用筛选的29条RAPD引物,对24份国外马铃薯品种进行遗传多样性分析。结果显示,29条RAPD引物共扩增出165个条带,其中116条为多态性条带,多态性比例为70.3%;试供的24个国外马铃薯品种间的遗传相似系数在0.514~0.816之间,平均为0.677;相似系数小于0.6的品种对仅为7.25%;24个马铃薯品种可聚为2大类6亚类。结果表明,试供的24个国外马铃薯品种间的遗传相似性高,遗传基础比较狭窄。     

36个马铃薯品种的SSR分析

为明确36个马铃薯品种在DNA分子水平上的遗传差异,利用SSR分子标记技术对其多态性进行了分析。试验从90对SSR引物中筛选出适宜于36个马铃薯品种基因组DNA扩增的引物10对,PCR扩增获得301个SSR条带,多态性条带百分率为71.1%。引物STACCA3和SSR111扩增的SSR指纹图谱差异明显,可作为36个马铃薯品种间鉴别的分子依据。36个马铃薯品种间的遗传距离(GD)变幅为0.33～0.85,平均为0.54,其中,大于GD平均值的品种有20个,占供试品种的55.56%。以GD值0.57为基准,将36个马铃薯品种划分成7类,从DNA分子水平揭示出各供试品种间的亲缘关系。     

富贵竹种质资源遗传多样性的ISSR分析

利用ISSR分子标记技术对10份富贵竹(Dracaena sanderiana)材料进行了遗传多样性研究。从 36个引物中筛选出 8个有效引物,共扩增出125条带,其中多态性条带为69条,多态性比率为55.2%,遗传相似性系数范围在0.64～0.95之间。根据ISSR标记的结果,采用UPGMA聚类分析方法,可将供试材料分为3大类群。研究结果表明, 供试富贵竹材料的遗传多样性相对较低,迫切需要拓宽富贵竹的遗传基础。     

克新系列马铃薯遗传多样性的RAPD分析

利用RAPD标记技术对19份克新系列马铃薯品种进行了遗传多样性分析,分别提取19份马铃薯品种的DNA,进行随机引物多态性扩增,从1000条随机引物中初步筛选出7条有多态性的引物进行详细研究,每条RAPD引物扩增出4~9条带,共获得52条带,其中多态性条带为43条;19份马铃薯品种的遗传距离介于0.17~0.72之间,平均值为0.39,平均遗传距离介于0.31~0.51之间;聚类分析结果在GS=0.53处可将克新系列马铃薯品种划分为三类,聚类结果与系谱分析基本相符,同时也说明克新系列马铃薯的遗传基础有所拓宽。研究表明：RAPD标记简便、快速、成本低,适用于分析马铃薯遗传多样性,指导马铃薯育种实践中的亲本组配。     

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.