14个八仙花品种亲缘关系的ISSR分析

利用ISSR技术对14个八仙花品种进行了亲缘关系的研究。从49个引物(引物选自加拿大哥伦比亚大学UBC公司公布的100条引物)中筛选了8个条带清晰、多态性高、重复性好的引物,对14个八仙花品种DNA进行扩增,共扩增出478条带(平均每个引物扩增59.75条DNA片段),多态性条带420条。用POPGENE分析数据得到14个品种的遗传距离为0.000 2～0.087 4,遗传相似性系数为0.916 3～1.000 0;利用NTSYSpc 2.1聚类分析,在遗传相似性系数约为0.38处将14个八仙花品种明显分为两大类,其中花园蕾丝、绿色夏天和圣代草莓被聚为第一类,其余11个品种被聚为第二类。     

红花品种遗传多样性的SRAP分析

利用相关序列扩增多态性SRAP(Sequence-related amplified polymorphism)技术对8份国内不同来源以及8份国外不同国家的,共计16份红花栽培种进行遗传多样性分析。选用20对多态性较高的引物组合对材料进行PCR扩增,而后进行聚丙烯酰胺凝胶电泳,获得多态性条带。共获得354条清晰的条带,其中,135条为多态性条带,多态性比率为38.14%。遗传相似系数在0.3~0.9之间,平均相似系数为0.65,表明红花种内不同栽培种之间具有较高的遗传多样性和相似性。     

不同基因型谷子的RAPD分析

利用随机多态性DNA (RAPD)分子标记技术分析了9种不同基因型谷子的遗传差异.采用20个随机引物对谷子基因组DNA进行RAPD-PCR扩增,共得到616条带,其中多态性条带有389条,多态性比例达到了63.2％.聚类分析表明,以遗传相似系数为0.68处可将9个谷子品种划分为3类.     

惠州引种马铃薯品种的ISSR分子鉴定

采用ISSR分子标记技术对7个惠州市引种的马铃薯品种进行遗传多样性研究.从30条ISSR引物中共筛选出3条引物,对7个马铃薯品种基因组DNA进行有效扩增,共扩增出25条带,其中多态性带20条,多态性比率为80%.用NTSYS-pc22.10 e软件计算各马铃薯品种阃的Jaccard遗传相似系数,7个马铃薯品种之间的遗传相似性系数界于0.35～0.85,平均遗传相似性系数为0.693.利用UPGMA进行的系统聚类分析表明,7个马铃薯可划分成2组,广引1号独立聚为一类,剩下6个马铃薯聚为另一大类.试验结果说明,引种的马铃薯品种间亲缘关系较近,遗传基础狭窄,有必要进一步扩大引种的数量和范围.     

22种石斛兰遗传多样性分析及DNA指纹图谱构建

为合理利用收集保存的石斛兰种质资源,采用ISSR分子标记方法对22种石斛兰的亲缘关系及遗传多样性进行分析。从100条引物中共筛选出6条扩增条带清晰、多态性高、重复性好的引物;利用筛选出的引物对22种石斛兰基因组DNA进行PCR扩增,共扩增出241条谱带,其中多态性谱带241条,多态性条带比例为100%;采用GenAlEx 6.5软件计算22种石斛兰的平均观测等位基因数(Na)为1.983,平均有效等位基因数(Ne)为1.167,平均Nei's遗传多样性指数(He)为0.133,平均Shannon信息多样性指数(I)为0.247,22种石斛兰表现出丰富的遗传多样性;采用NTSYS-pc 2.1软件计算22种石斛兰的遗传相似系数为0.698 4～0.878 7;基于遗传相似系数进行UPGMA聚类,在相似系数0.795处,可将22种石斛兰划分为10个类群,UPGMA聚类结果与传统的形态学分类结果一致。利用3对引物构建的DNA指纹图谱均可单独鉴别出22种石斛兰。该研究为石斛兰种质资源鉴定、杂交育种亲本选择等提供了理论基础。     

柳州汪洞乡古茶树种质资源遗传多样性的ISSR分析

本研究利用ISSR分子标记技术对柳州融水县汪洞乡古茶树种质资源的遗传多样性和亲缘关系进行分析,选取10个ISSR引物对87株柳州汪洞乡古茶树单株及4个对照茶树品种的基因组DNA进行扩增。10条引物共扩增出67条谱带,其中多态性条带共64条,多态性比率达95.5%,每条引物扩增条带为5~9条,平均多态性条带6.4条。每条引物扩增条带的多态性为80%~100%,扩增条带大小在100~2 000 bp。供试样品的Jaccard相似系数在0.35~0.85之间,平均值为0.60。在相似系数0.6处可将全部91份样品划分为10大类群。本研究从分子水平上揭示了该古茶树群体资源单株间的亲缘关系,可为该资源的进一步开发利用提供研究基础。     

观赏向日葵种质资源遗传多样性RAPD分析

利用RAPD标记技术,从90条随机引物中筛选出16条对16个观赏向日葵种质资源进行DNA水平上的多态性检测,共获得242条DNA片段,大小分布在200～2800 bp之间,其中162条带具有遗传多态性,约占总数的66.9%,揭示了观赏向日葵较为丰富的遗传多样性.16个观赏向日葵的遗传相似性分析表明,各基因型间的Nei氏相似性系数分布在0.36～0.84之间,平均相似性系数为0.590 3;聚类分析结果在一定程度上可区分出不同的基因型,多数来源相同的种质资源表现出较为密切的亲缘关系.     

菜心ISSR分子标记技术初步研究

以菜心为研究对象,初步建立起菜心的ISSR分子标记技术体系,包括DNA提取、退火温度、循环次数和引物筛选等.对退火温度进行优化,确定最佳退火温度为48℃,最优循环次数为45次.共筛选了49条引物,其中11条引物能扩增出多态性带,选择4个条带清晰的引物对6个品种进行扩增,共检测出32条带,其中多态性带为22条,多态性比例为68.80%,6个品种的遗传相似性系数为0.19～0.77.说明ISSR标记能够揭示材料间较高的遗传多样性,本试验为菜心的种子纯度鉴定和新品种选育提供理论依据.     

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。     

贵州桃种质资源ISSR标记体系建立及遗传多样性分析

采用正交设计方法,针对影响贵州桃ISSR-PCR反应的引物浓度、模板DNA、Master Mix及退火温度等因素进行优化,建立了适于贵州桃ISSR-PCR标记的反应体系。20μL反应体系含有Master Mix 10.0μL、引物浓度0.375μmol/L、DNA模板40 ng、退火温度为52℃。利用该体系对71份贵州桃资源进行分析,扩增条带清晰,扩增产物在175~2 300 bp之间。12条ISSR引物共扩增112条带,其中多态性条带79条,多态性比率为70.54%。供试材料的Nei's遗传多样性指数(H)为0.211 1±0.184 4,Shannon's信息指数(I)为0.325 1±0.260 8。聚类分析显示71份贵州桃资源遗传相似系数变幅为0.669 6~0.919 6,在相似系数0.80水平处可将供试材料分为8个类群,表明贵州桃资源具有较为丰富的遗传多样性。     

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.     

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.