New PCR based markers allowed to identify <Emphasis Type="Italic">Secale</Emphasis> chromatin in wheat-<Emphasis Type="Italic">Secale africanum</Emphasis> introgression lines

The genus of Secale has many agronomically important characters. In order to use the best of this species, markers tracking the rye chromatin incorporated into wheat must be developed. In this study, one rye genome-specific random amplified polymorphic DNA (RAPD) marker was isolated from Secale africanum (R^a genome). Two cloned markers, named OPP13₁₁₆₅ and OPP13₆₆₂, were 1165 bp and 662 bp, respectively. Sequence analysis revealed that OPP13₁₁₆₅ was highly homologous to a part of a new class of transposon-like gene called the Revolver family, and OPP13₆₆₂ was partially similar to LTR gypsy-like retrotransposon. Fluorescence in situ hybridization (FISH) showed only OPP13₁₁₆₅ localized within the whole arms of rye except their terminal regions and no signal was detected on wheat chromosomes, while OPP13₆₆₂ had no hybridization signal detected on wheat and rye genomes. Based on these sequences, two pairs of sequence-characterized amplified region (SCAR) primers were designed, and the resulted SCAR markers were able to target both cultivated and wild Secale species. The FISH patterns and the two SCAR markers should be able to identify and track all wheat-rye translocation lines, especially the S. africanum chromatin.     

Relationships among <Emphasis Type="Italic">Leymus</Emphasis> species assessed by RAPD markers

The DNA genetic diversity of 40 accessions of genus Leymus was analyzed by random amplified polymorphic DNA (RAPD) markers. A total of 352 products were amplified by 34 10-mer arbitrary primers, among which 337 products (95.74 %) were found to be polymorphic. 5–14 polymorphic bands were amplified by each polymorphic primer, with an average of 9.91 bands. The data of 352 RAPD bands were used to generate Jaccard’s similarity coefficients and to construct a dendrogram by means of UPGMA. Great genetic diversity in genus Leymus was observed, the genetic diversity among the different species more abundant than that of the different accessions, and the different accessions in a species or the species from the same areas were clustered together.     

Isolation and chromosomal distribution of a novel Ty1-copia-like sequence fromSecale, which enables identification of wheat—Secale africanum introgression lines

A repetitive sequence of 411 bp, named pSaO5₄₁₁, was identified in theSecale africanum genome (R^a) by random amplified polymorphic DNA (RAPD) analysis of wheat and wheat—S. africanum amphiploids. GenBank BLAST search revealed that the sequence of pSaO5₄₁₁ was highly homologous to a part of a Ty1-copia retrotransposon. Fluorescence in situ hybridization (FISH) analyses indicated that pSaO5₄₁₁ was significantly hybridized toS. africanum chromosomes of a wheat—S. africanum amphiploid, and it was dispersed along theSecale chromosome arms except the terminal regions. Basing on the sequence of pSaO5₄₁₁, a pair of sequence-characterized amplified region (SCAR) primers were designed, and the resultant SCAR marker was able to target both cultivated rye and the wildSecale species, which also enabled to identify effectively theS. africanum chromatin introduced into the wheat genome.     

Chloroplast DNA variation in the genusSecale (Poaceae)

The chloroplast genomes of 44 accessions ofSecale were surveyed for restriction site polymorphisms. The accessions were chosen to represent the geographic as well as taxonomic range of the genus. Using 12 restriction enzymes a total of 348 sites were detected. Twenty-nine mutation sites were phylogenetically informative and used in a cladistic analysis. Further, a 0.1 kb insertion separatedSecale from the outgroup species. Only the annual speciesS. sylvestre was distinct from the rest of the taxa. Cultivated rye together with both wild annual and wild perennial accessions were mixed among each other. Sequence divergence (p) among taxa ofSecale was low, varying from 0.000 to 0.005, suggesting a rather recent origin of the genus.     

RAPD Profiling in Detecting Genetic Variation in Endemic Coelonema (Brassicaceae) of Qinghai-Tibet Plateau of China

Random amplified polymorphic DNA (RAPD) markers were used to measure genetic diversity of Coelonema draboides (Brassicaceae), a genus endemic to the Qilian Mountains of the Qinghai-Tibet Plateau. We sampled 90 individuals in 30 populations of Coelonema draboides from Datong and Huzhu counties of Qinghai Province in P.R. China. A total of 186 amplified bands were scored from the 14 RAPD primers, with a mean of 13.3 amplified bands per primer, and 87% (161 bands) polymorphic bands (PPB) was found. Analysis of molecular variance (AMOVA) shows that a large proportion of genetic variation (84.2%) resides among individuals within populations, while only 15.8% resides among populations. The species shows higher genetic diversity between individuals than other endemic and endangered plants. The RAPDs provide a useful tool for assessing genetic diversity of rare, endemic species and for resolving relationships among populations. The results show that the genetic diversity of this species is high, possibly allowing it to adapt more easily to environmental variations. The main factor responsible for the high level of differentiation within populations and the low level of diversity among populations is probably the outcrossing and long-lived nature of this species. Some long-distance dispersal, even among far separated populations, is also a crucial determinant for the pattern of genetic variation in the species. This distributive pattern of genetic variation of C. draboides populations provides important baseline data for conservation and collection strategies for the species. It is suggested that only populations in different habitats should be studied and protected, not all populations, so as to retain as much genetic diversity as possible.     

Relations between Photosynthetic Pigment Accumulation and Microsporogenesis in Secale, Triticale, and Secalotriticum

The accumulation of photosynthetic pigments in underflag and flag leaves as well as the process of microsporogenesis in lines of tetraploid Secale, hexaploid Triticale, and hexaploid Secalotriticum were studied. Significant positive correlations were found between the amounts of chlorophyll a (Chl a), carotenoids (Car), Chl a/b ratio, and the normal proceeding of meiosis. High probability of paternal type of inheritance of specifities of meiosis of pollen mother cells and variation in photosynthetic pigments during plant transition from the stalk-shooting to heading stage were demonstrated.     

应用SRAP标记绘制88份南瓜属种质资源DNA指纹图谱

为了给南瓜属种质资源鉴定和分类提供分子生物学依据,本研究采用SRAP分子标记技术与DNAMAN指纹图谱绘制软件对88份南瓜属种质资源(包含美洲南瓜、中国南瓜、印度南瓜)进行分子指纹图谱绘制。结果表明:35对SRAP多态性引物共扩增出499条清晰条带,其中多态性条带438条,多态性条带比率高达87.8%。根据扩增出的条带成功绘制出88份南瓜属种质资源的DNA指纹图谱,每一份种质都具有其独特的分子身份证,使得每份种质均可被区别开来。其中,多态性最好的引物是E5EM8,可以同时绘制72份南瓜属种质资源的指纹图谱。所有供试材料用5对多态性SRAP引物即可全部区别开来。研究表明,SRAP分子标记技术可成功地绘制南瓜属种质资源DNA指纹图谱。本研究对南瓜属种质资源鉴别、分子数据库构建及品种权保护具有较重要的意义。     

秦岭山区美容杜鹃五个野生种群遗传多样性的ISSR分析

美容杜鹃是杜鹃花科杜鹃花属常绿观花植物,也是秦岭地区的特有属,在维持当地生态平衡方面发挥着重要作用,但目前资源正在遭受严重的破坏。该文通过ISSR分子标记技术对秦岭地区5个美容杜鹃野生种群进行遗传多样性分析,了解美容杜鹃不同种群的遗传分化,从而为美容杜鹃野生种质资源保护策略的制定提供理论依据。用8个ISSR引物对5个天然种群的90个单株进行扩增,共扩增出78条带(平均每条引物产生9.75条带),其中65条带是多态的,多态位点占总位点的百分率为83%。种群总的Nei’s基因多样性指数为0.3386,Shannon信息多态性指数为0.4972,表明美容杜鹃总的遗传多样性水平较高。种群多态位点百分率为82.71%~90.25%,Shannon信息多态性指数为0.4161~0.5867,Nei’s基因多样性指数为0.3044~0.4122,表明美容杜鹃不同种群遗传多样性水平差异较大。其中镇安木王种群和柞水牛背梁种群的遗传多样性水平较高。AMOVA分析表明种群内的遗传变异(91.22%)大于种群间的遗传变异(8.78%)。UPGMA聚类分析表明5个种群的遗传分化程度与地理距离没有相关性。因此建议尽可能地保护美容杜鹃所有的天然种群原生境条件,以最大限度保护其遗传变异。由于镇安和柞水种群具有较高的遗传多样性,因此建议优先对这2个种群实施就地保护和迁地保护。     

Electrophoretic analysis of the lipopolysaccharides ofBacteroides spp.

Lipopolysaccharide (LPS) extracts of reference strains and isolates ofBacteroides spp. prepared by the proteinase K method were resolved by tricine-sodium-dodecyl-sulphate-polyacrylamide gel electrophoresis and located by silver staining. A considerable diversity of LPS profiles was evident within theBacteroides genus although profiles were essentially species-specific, with some minor interstrain variations apparent among isolates ofB. uniformis, B. ovatus, B. eggerthii andB. thetaiotaomicron. The LPS of most species consisted of a major rough LPS component of 2–5 kDa and a series of higher molecular weight bands which varied with species.B. vulgatus LPS was distinctive in showing an extensive ladder of multiple repeating oligosaccharide units with molecular weights ranging from 4 to >17 kDaB. stercoris LPS included a high molecular weight (>17 kDa) ladder of repeating oligosaccharide units.B. fragilis andB. thetaiotaomicron differed from most other species in producing a short ladder of repeating oligosaccharide units interspersing the rough LPS and a 5.6 kDa (B. fragilis) or 9 kDa (B. thetaiotaomicron) yellow-staining component. The heterogeneity of LPS profiles within theBacteroides genus may reflect the differences in pathogenicity among the species and prove useful for typing.     

应用RAPD分子标记技术探讨3种石斛属植物的种间关系

采用RAPD分子标记技术,分析了金钗石斛、铁皮石斛和齿瓣石斛三种石斛属植物的种间关系。10个引物产生的113条DNA扩增片段中,106条（93.81%）具有多态性,利用113个RAPD标记,计算遗传距离,利用非加权组平均法建立聚类图。结果表明,RAPD标记技术较好地从分子水平揭示金钗石斛、铁皮石斛和齿瓣石斛三种石斛属植物的遗传背景、亲缘关系,并为后期在DNA水平上对药用石斛的开发利用提供资料。     

40份玉米自交系的ISSR遗传多样性分析

利用ISSR分子标记技术对40份玉米自交系进行亲缘关系分析。从59条ISSR引物中筛选出10条重复性高、多态性好的引物,分别对全部供试材料进行扩增,共扩出90条清晰谱带,其中多态性条带81条,多态性比率为90.00%,表明供试材料基因组DNA的多态性较高。用 NTSYSpc-2.10软件中的 UPGMA进行聚类分析,40份玉米自交系的遗传相似系数变化范围在0.65~1.00之间,在此基础上构建聚类分析树状图,揭示了玉米各自交系间的亲缘关系。本研究为今后分子水平上玉米优良自交系的改良与选育提供了一定的参考依据。     

应用ISSR标记研究仲彬草属植物的遗传变异

利用ISSR标记对仲彬草属14个种和1个变种共32份材料进行了研究。结果表明:仲彬草属材料间ISSR标记多态性较高,变异较大。12个引物共扩增出593条带,其中535条(90.2%)具有多态性,每个引物可扩增出11~80条多态性带,平均44.6条。ISSR标记遗传相似系数在种间变化范围为0.430~0.866,平均值为0.620。从聚类分析得知,ISSR标记能将32份仲彬草属材料完全分开,32份材料聚为4类。同种不同居群的材料分别聚在一起,亲缘关系较近,同时,在分子水平上种内不同居群间也存在分化;种间存在明显的遗传差异;形态相似、地理分布一致的物种倾向于聚类在一起,有一定的亲缘关系。因此,ISSR分子标记能有效地评价仲彬草属物种的亲缘关系。     

菘蓝二倍体及其同源四倍体遗传差异的ISSR分析

以1个菘蓝二倍体及其10个同源四倍体株系为材料,利用19个随机扩增ISSR引物分析其遗传差异性,为菘蓝多倍体诱变的基因表达调控以及遗传改良提供依据。结果显示:菘蓝二倍体与其同源四倍体及四倍体之间的ISSR多态性有明显差异,除主要遗传位点相同外,有些四倍体株系扩增条带数多于二倍体,有些四倍体株系扩增条带数少于二倍体,四倍体株系间亦有多态位点;11个株系共扩增111条多态性条带,多态性达55.22%。聚类分析显示,不同四倍体株系与二倍体的遗传差异大小亦不同。研究表明,菘蓝二倍体与其同源四倍体具有中等偏高的遗传差异性。     

忍冬属植物的遗传多样性及其种间关系研究

应用RAPD标记技术对甘肃省境内的23种忍冬属(Lonicera Linn．)植物的遗传多样性及其种间关系进行了探讨。从34个随机引物中共选出9个多态性和重复性较好且谱带清晰的引物,这9个引物扩增出的DNA片段大多在300～3000bp之间,所形成的多态性位点数差距较大。POPGENE 1．31软件分析结果表明：甘肃省忍冬属植物具有较为丰富的遗传多样性,其多态性比率为71．93％,Shannon多样性指数与Nei指数分别为0．3230和0．2086。Nei‘s遗传距离和UPGMA分析结果显示,23种忍冬明显地聚为2大类,其下又有较多分支,即隶属于同一亚组或相近亚组的不同种基本归为一类,其种间关系与传统的形态学分类结果基本一致。但也有个别种的归属及种间关系稍有变化,如形态学上差异较大的毛药忍冬和毛花忍冬在本研究中聚在一起。这可能与不同的分类水平有关。     

14个板栗品种遗传多样性的RAPD分析

利用RAPD分子标记手段,研究板栗品种的遗传多样性。采用从100个随机引物筛选的20个引物对14个板栗品种的基因组DNA进行扩增,通过对140条谱带的聚类,分析了供试板栗品种的系统发育;运用特殊谱带,建立了板栗品种的分子检索表,结合扩增的特殊位点,提出了重点保存的板栗品种。     

The structure,amount and chromosomal localisation of defined repeated DNA sequences in species of the genus Secale

The structure, copy number and chromosomal location of arrays of four families of highly repeated sequences have been investigated in representative species of the genus Secale. The four unrelated families, previously characterised in Secale cereale, have repeating units of 480, 610, 630 and 120 base pairs respectively. The following general conclusions can be drawn in addition to detailed knowledge of the sequence content of heterochromatin in each accession studied: (1) Every species is unique in its complement or chromosomal distribution or both of the four highly repeated sequence families. S. montanum and S. cereale accessions studied here show the same complement of repeated sequences, but they differ substantially in the amounts they contain of the 610 and 630 base pair (bp) families, and in the distribution over the chromosomes of the 480 bp family. The structure of the repeating unit is also different in many members of the 480 bp family in S. montanum. — (2) The substantial differences between species in the amounts of the most highly repeated DNA sequences exist in the absence of any such conspicuous differences in most other repeated sequences which were detected as fluorescent bands after restriction enzyme digestion and gel electrophoresis. — (3) Each of the different highly repeated families can exist independently of the other families, though all the families have telomeric sites. Also, in the outbreeding species, heteromorphisms are frequent, and are particularly conspicuous in hybridisation detecting the 480 bp sequence family. — (4) The association of the highly repeated sequences with heterochromatin, discussed in the accompanying paper is generally true for other species in the genus, and the lower amounts of heterochromatin in other Secale species compared to S. cereale are associated with lower amounts of specific families of highly repeated DNA sequences. — (5) Analysis of highly repeated sequence families is likely to provide an easy method of identification of new accessions of Secale.     

Genetic variation of the genus Kengyilia by ISSR markers

We investigated the genetic variation within 32 accessions distributed to 14 species and one variety by using ISSR (inter-simple sequence repeat) markers. The results showed that genetic variation was relatively higher among the accessions. A total of 593 bands were amplified by 12 ISSR primers, of which 535 bands (90.2%) were polymorphic. Eleven to 80 polymorphic bands were amplified from each prime, with an average of 44.6 bands. The interspecies GS (genetic similarity) value ranged from 0.430 to 0.866, and the average was 0.620. Cluster analysis showed that all accessions could be classified into 4 groups by ISSR markers. The different accessions in a species were clustered together, but they had genetic variation in molecular levels. There was obvious interspecies genetic variation. Species with similar morphological characteristics and from the same areas or neighboring geographical regions were clustered together and had close relationships. ISSR markers are useful in analyzing interspecies variation in Kengyilia. __________ Translated from Guihaia, 2006, 26 (4): 375–380 [译自: 广西植物]     

Cytogenetic evolution in the Triticinae: Homoeologous relationships

The subtribe Triticinae consists of five genera, namely Aegilops, Agropyron, Haynaldia, Secale and Triticum, all with x=7 as the basic number and possibly derived from a common ancestor (PP). The homoeologous relationships known to exist between individual chromosomes from different genomes of hexaploid wheat, are being extended to other members of the subtribe. The available work in the area of homoeologous relationships in the subtribe Triticinae has been reviewed in detail. Homoeologous relationships of one chromosome of each of the four species of Aegilops i.e. Ae. comosa, Ae. caudata, Ae. umbellulata and Ae. bicornis are now known. Similarly, in the genus Agrophyron, relationships of six chromosomes of A. clongatum (2n=70), two chromosomes of A. clongatum (2n=14) and of two chromosomes of A. intermedium are known. The genus Secale, for which the author's own work is also available, has been most extensively studied and relationships of at least five chromosomes of S. cereale are now known. No other species of Secale has been used in similar studies. In the genus Haynaldia, no chromosome could be shown to have any relationship with a wheat chromosome, perhaps due to low erossability with Triticum aestivum. The above work has been discussed and reviewed.     

用RAPD分子标记探讨沙拐枣属的种间关系

利用随机扩增多态性DNA（RAPD）技术分析了14种沙拐枣属（Calligonum L.)植物,通过对16个Sangon公司十聚体随机引物进行PCR扩增,3个引物能产生多态性带。对3个引物扩增产生的45条扩增产物,计算单匹配系数,应用UPGMA方法构建亲缘关系树状图。分析结果表明：（1）物种间遗传差异明显,具有丰富的遗传多样性;（2）14种沙拐枣属植物明显聚为4类,与传统的形态学分类结果基本一致。