台湾水青冈ISSR-PCR体系的优化

分析了ISSR-PCR体系中Mg2+、dNTP和BSA浓度,以及模板DNA、引物和TaqDNA聚合酶用量等6个因素对反应结果的影响,建立了适合于台湾水青冈ISSR-PCR扩增的反应体系:10μL PCR反应液中,含10 ng DNA,1.5 mmol.L-1Mg2+,0.125 mmol.L-14×dNTP,1×TaqDNA聚合酶配套缓冲液(10 mmol.L-1Tris-HCl,pH值9.0,50 mmol.L-1KCl,0.1%Triton X-100),0.6 UTaqDNA聚合酶,2 mg.mL-1BSA和3pmol引物。应用优化的ISSR-PCR体系从100个ISSR引物中筛选出12个稳定性好,重复性高的引物,对22株台湾水青冈个体的DNA进行扩增,结果表明优化的ISSR-PCR体系完全适合于台湾水青冈的ISSR分析。     

Isozyme and RAPD polymorphisms in Heterobasidion annosum in Italy

Isozyme and random amplified polymorphic DNA (RAPD) polymorphisms were used to study variability in a group of 41 isolates from the Italian population of Heterobasidion annosum. The isolates belonged to the intersterility groups P and S, and particularly to the group that is most widely distributed in Italy, group F. Isozyme analysis was effective in identifying the three intersterility groups and revealed a high degree of genetic divergence within the P group isolates; the mannose phosphate isomerase (MPI-2) locus was diagnostic in the attribution of isolates to the more correlated F and S groups. RAPDs were detected following amplification by the polymerase chain reaction (PCR). 74 RAPD fragments, obtained through amplifications with eight primers, were scored. Isolates from the 3 intersterility groups were clearly divergent based on analysis of RAPD markers. However, a similarity index calculated for the isolates within the F population indicated a high uniformity of the isolates collected throughout the Italian peninsula.     

Relationships between gas exchange and carbon isotope discrimination of Sitka x interior spruce introgressive genotypes and ribosomal DNA markers

Effects of hybridization on physiological performance were investigated in seven natural introgressive populations and one F(1) population of Sitka (Picea sitchensis (Bong.) Carr.) x interior spruce (P. glauca (Moench) Voss. x P. engelmannii Parry ex Engelm.). Each population was represented by a Sitka-interior spruce ribosomal DNA (Si rDNA) index that was calculated from the relative abundance of species-specific DNA polymorphisms. Gas exchange parameters were measured under well-watered conditions on current-year needle tissues, which were also analyzed for carbon isotope discrimination. Sitka spruce populations had higher gas exchange rates (net photosynthesis, stomatal conductance to water vapor), but lower carbon isotope discrimination values than interior spruce populations. The natural hybrid populations had intermediate values of these parameters consistent with their Si rDNA index. The F(1) population had gas exchange parameters resembling those of Sitka spruce populations, but its carbon isotope discrimination was skewed toward that of interior spruce populations. These results confirmed previous findings that physiological performance of introgressive hybrid spruce populations varied as their DNA constitution changed.     

江西省7种新记录植物

报道7种江西新分布的植物,即小叶南烛Vaccinium bracteatum var. chinense (Lodd.) Chun ex Sleumer、仿栗Sloanea hemsleyana (Ito) Rehd. Et Wils.、厚叶石斑木Rhaphiolepis umbellate (Thunb.) Makino、狭叶黄牛奶树Symplocos laurina (Retz.) Wall. ex G. Don var. bodinieri (Brand) Hand.-Mazz.、深圆齿堇菜Viola davidii Franch.、光枝米碎花Eurya chinensis var. glabra Hu&L. K. Ling、菱叶菝葜Smilax hayatae T. Koyama。     

Restriction map and polymorphisms of nuclear ribosomal genes of Populus balsamifera

Balsam poplar (Populus balsamifera) clones from five populations, which were collected along a transect from northern Wisconsin to the northern tree line, were evaluated for polymorphisms in nuclear ribosomal DNA. For this purpose, a restriction map was constructed using four six-cutter enzymes in single and double digests of genomic DNA. After electrophoretic separation on agarose gels and Southern transfer, blots were hybridized to non-radioactively labeled heterologous rDNA probes of soybean. Among populations, variation was detected in the length of the intergenic spacer between the tandem repeats of the coding regions and in the degree of methylation of one restriction enzyme recognition site. Based on a comparison of the derived restriction map of balsam poplar and other poplars, high homology was evident in the rDNA coding regions among species, whereas the intergenic spacer varied slightly in both length and number of restriction sites.     

AFLP标记在毛新杨×毛白杨BC1群体中的分离

利用AFLP分子标记技术 ,以毛新杨×毛白杨BC1群体中的 12 0个单株为材料 ,在整个基因组水平上研究AFLP标记在该群体中期望的孟德尔分离情况 .4 1对AFLP引物组合共检测到 2 70 7个位点 ,其中在分离群体的亲本毛新杨和毛白杨间具有多态性的位点有 712个 .经卡方检验后得到在P <0 .0 1水平上 ,符合期望孟德尔 1∶1分离的位点共有 5 71个 ,占多态性位点的 80 .2 % ,该结果表明AFLP标记技术很适合用于毛白杨指纹分析和遗传连锁图谱构建     

RFLPs IN INTERNAL TRANSCRIBED SPACERS OF RIBOSOMAL DNA FROM THREE SPECIES OF TILITIA

ManyTilletiasPeciesareAnPohanplantpathogenswithworldwidedistribution.TilletialaevisKuhnandrtrihei(Bjerk.)Winter,tkatincitecommonbuntdiseaseofwheat,andTcontroversaKuhn,whichincitesdWatbuntdiseaseofwheat,arecloselyrelatedfilamen-todsbasidiomvcetCs.TcontroversaislistedasquarantinePestbysomeunepidedriccountriesbecauseofitsscriJusdamapeanddifficulty'tocontfol.Tlael,:,withnoreticulationontelio-sPOrewall,isdistinctmorphologicallyfrom77conho1)`,rsaandTtriIici.However'therearemorPhologicaloverl…     

A molecular marker associated with low-temperature induction of dormancy in red osier dogwood (Cornus sericea)

Dormancy induction in temperate deciduous plants is thought to be regulated by short photoperiods, but low temperature has been shown to eliminate the short photoperiod requirement in northern ecotypes. An F2 population (191 plants) red osier dogwood (Cornus sericea L.) derived from a polycross of an F1 population produced from reciprocal crosses of the parental clonal ecotypes, Northwest Territories (NWT, 62 degrees N) and Utah (42 degrees N), was examined to identify molecular markers of temperature-induced endodormancy. Dormancy induction curves were generated for each individual in the F2 population and a standard point prior to vegetative maturity (i-VM) was inferred from the change in slope of the dormancy acquisition curve. Under Saskatoon, Saskatchewan field conditions (52 degrees N), the NWT ecotype entered i-VM on average 5-6 weeks before the Utah ecotype. Two sub-populations of the F2 population were distinguishable based on VM acquisition on exposure to low temperature but not to short photoperiods. A sequence characterized amplified region (SCAR) marker was developed that correctly (> 92%) identified individual plants within the F2 subpopulation that were responsive to low-temperature induction of VM. Timing of bud break was strongly associated with the timing of VM in the geographical ecotypes but not in the F2 population, indicating that these are separate traits under genetic control.     

Plant somatic hybrid cytoplasmic DNA characterization by single-strand conformation polymorphism

Unlike maternal inheritance in sexual hybridization, plant somatic hybridization allows transfer, mixing and recombination of cytoplasmic genomes. In addition to the use of somatic hybridization in plant breeding programs, application of this unique tool should lead to a better understanding of the roles played by the chloroplastic and mitochondrial genomes in determining agronomically important traits. The nucleotide sequences of cytoplasmic genomes are much more conserved than those of nuclear genomes. Cytoplasmic DNA composition in somatic hybrids is commonly elucidated either by length polymorphism analysis of restricted genome regions amplified with universal primers (PCR-RF) or by hybridization of total DNA using universal cytoplasmic probes. In this study, we demonstrate that single-stranded conformational polymorphism (SSCP) analysis is a powerful, quick and easy alternative method for cytoplasmic DNA characterization of somatic hybrids, especially for mitochondrial DNA. The technique allows detection of polymorphisms based on both size and sequence of amplified targets. Twenty-two species of the subfamily Aurantioideae were analyzed with eight universal primers (four from chloroplastic and four from mitochondrial regions). Differences in chloroplastic DNA composition were scored in 98% of all possible two-parent combinations, and different mitochondrial DNA profiles were found in 87% of them. Analysis by SSCP was also successfully used to characterize somatic hybrids and cybrids obtained by fusion of Citrus sinensis (L.) Osb. and C. excelsa Wester protoplasts.     

Genetic variation and mtCOI phylogeny for Bemisia tabaci (Hemiptera, Aleyrodidae) indicate that the ‘B’ biotype predominates in Iran

Despite a large number of investigations on the molecular genetics and population structure of the whitefly Bemisia tabaci (Gennadius) complex, no such study had been conducted in Iran. The genetic variation of B. tabaci was examined using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) for 18 field collections from cucumber, eggplant, and tomato in four provinces of Iran. PCR amplification and restriction digestion with two enzymes detected 388 RFLP fragments, of which 16 fragments showed polymorphisms. Cluster analysis of these data placed all B. tabaci individuals within a single group, and there was no evidence for between- or within-population genetic variation. Phylogenetic (Clustal W) analysis of 42 B. tabaci mtCOI sequences (n = 21 field collections) from Iran, and a comparison with well-studied haplotype or biotype reference sequences available in public sequence databases, revealed that the Iranian B. tabaci populations were most closely related to the B biotype at 0–1.2% nucleotide identity. The B biotype is a well-known member of a sister clade from the Middle East–North African region of the world, owing to its nearly worldwide distribution and invasive characteristics. This report indicates that a single major haplotype of B biotype is prevalent in Iran and that its closest relative is the B biotype. Also, given the extent of known variation in the Middle East and African continent, data indicate somewhat surprisingly that the B. tabaci collections sampled in Iran had limited genetic variation and population substructure. Knowledge that the B biotype of B. tabaci predominates in Iran is important for designing effective pest management strategies given that biotypes of B. tabaci are known to differ greatly with respect to insecticide resistance, host range, virus–vector interactions, and other key biological characteristics.     

水分胁迫对杂种马褂木与双亲重要生理性状的影响

水分胁迫状态下鹅掌楸属 (Liriodendron)种间正反交F1 杂种及双亲的一些重要生理性状的研究表明 :水分胁迫状态下亲本与杂种叶片的相对含水量、叶绿素含量、蛋白质含量的降低速率和RNase活力的升高速率排序为马褂木 >北美鹅掌楸 >正交F1 >反交F1 ;短时间水分胁迫对马褂木伤害最大。3H Gly标记取得的直接证据证明 ,水分胁迫导致亲本与杂种RNase基因在翻译水平上表达而从头合成RNase ,RNase基因表达强度排序为马褂木 >北美鹅掌楸 >正交F1 >反交F1 。蛋白质生物合成抑制剂取得的间接证据表明 ,水分胁迫状态下双亲RNase活力升高除与细胞质mRNA翻译有关外 ,还可能涉及叶绿体和 或线粒体RNase的释放、活化和 或合成 ,而正反交杂种RNase活力升高可能主要来自细胞质mRNA的翻译而不涉及到叶绿体和 或线粒体。上述实验证据充分证明 ,杂种马褂木正反交F1 杂种具有对水分胁迫抗性的显著超亲杂种优势 ,而正反交杂种中反交F1 的抗性又强于正交F1 。研究结果从水分胁迫抗性差异角度揭示了杂种马褂木强大正向生长、适应性和抗性杂种优势现象形成的分子机理 ,并表明在杂种马褂木杂种优势固定利用实践中必须特别注意反交F1 杂种无性系的选育与开发     

刺五加AFLP分子标记技术体系的建立

用改良的的试剂盒法提取刺五加叶片的基因组DNA,可以获得高质量的刺五加基因组DNA,DNA降解较少、污染低、电泳条带清晰,可以用于PCR扩增反应,可以被内切酶EcoRⅠ和MseI彻底消化。通过优化酶切反应、引物连接、预扩增、选择扩增,建立了优化的刺五加AFLP分析技术体系,从64对引物中筛选到5对高效扩增引物,并利用这5对引物在6个刺五加种源中获得了89个多态性AFLP分子标记。建立了利用红外荧光检测技术和Li-Cor4300DNA分析系统,进行刺五加AFLP分析的分子标记技术。     

Assembling a physical map of the genome by marker sequences

lntroductionAfteragenomehasbeenfragmented,thefrag-mentsclonedtogenerateagen0miclibrary.ltisnecessaryt0assemblethecIonedfragmentsinthesameIinearorderasfoundinthechromos0mesfromwhichtheyarederived.OnemethodofIinkingcIonedfragmentswaschromosomewalking(Benderetal.1983),whichwasoriginaIlydevelopedfOrtheis0Iationofgenesequenceswhosefunctionwasunknownbutwhosegeneticlocationwasknown.Forthepurposesofmapping,asinglecIonedfragmentwasseIectedandusedasapr0betodetectotherclonesintheIibrary,withwhichthep…     

RFLPs in internal transcribed spacers of ribosomal DNA from three species ofTilletia

DNA polymorphisms were evaluated for the eight strains representingTilletia controversa Kuhn,T. laevis Kuhn andT. tritici (Bjerk.) Winter using polymorase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. DNA regions coding for the internal transcribed spacers (ITS) were amplified and digested with five four-base restriction enzymes (Msp I,Hinf I,Taq I,Hha I andHae III). No differences were shown in the PCR-RFLP patterns among the strains tested. This indicatedT. controversa, T. laevis andT. tritici are very closely related. This study was supported in part by systematic Mycology & Liohenology Laboratory of Sciance Institute of China     

筛选与杨树抗云斑天牛基因连锁的RAPD标记

筛选与杨树抗云斑天牛基因连锁的ＲＡＰＤ标记王京兆，王斌，卞学瑜，韩一凡（中国科学院遗传研究所北京１００１０１）（中国林业科学研究院林业研究所北京１０００９１）关键词杨树，云斑天牛，ＲＡＰＤ，多态性产物植物抗虫基因工程是当前比较活跃的研究领域，但真正能...     

Nuclear,chloroplast, and mitochondrial DNA polymorphisms as biochemical markers in population genetic analyses of forest trees

DNA analyses have been used only occasionally to investigate genetic polymorphisms in forest tree populations. Nonetheless, these analyses have already contributed to significant discoveries, such as paternal chloroplast and maternal mitochondrial DNA inheritance in Pinaceae. DNA polymorphisms will be increasingly exploited in the future by forest population geneticists, because available technology permits large sample sizes and yields excellent resolution. The utility of chloroplast, mitochondrial, and nuclear DNA polymorphisms is expected to be greatest when less expensive genetic markers are unavailable, insufficiently numerous, or ineffectively polymorphic. For example, DNA fingerprinting may permit the unambiguous elucidation of genetic relationships within and among populations of woody species.     

Genetische Methoden zur Schädlingsbekämpfung

Summary Genetics has provided means for the improvement of livestock and crop and guidelines for the betterment of human populations (eugenics). Only very recently interest has turned also to deleterious genetic factors and mechanisms for control and eradication of pests (dysgenics). As probable candidates for such measures are listed: cytoplasmic incompatibility, hybrid sterility, artificial sterilization, translocations, inversions and deleterious genes. These mechanisms are described briefly and their use for control is discussed. In this evaluation it turus out that besides cytoplasmic incompatibility the use of translocations would be very promising (Fig. 2). Other mechanisms have certain drawbacks and the application of deleterious genes seems to have the least prospects (Fig. 3). Total eradication of a field population of Culex fatigans by cytoplasmic incompatibility is reported (Fig. 1).     

Use of DNA markers in forest tree improvement research

DNA markers are rapidly being developed for forest trees. The most important markers are restriction fragment length polymorphisms (RFLPs), polymerase chain reaction- (PCR) based markers such as random amplified polymorphic DNA (RAPD), and fingerprinting markers. DNA markers can supplement isozyme markers for monitoring tree improvement activities such as; estimating genetic diversity in breeding populations, germplasm identification, verifying controlled crosses, and estimating seed orchard efficiencies. Because the number of DNA markers is potentially limitless, it should be possible to map individual quantitative trait loci (QTL) by linkage analysis with high-density maps. Finally, if such associations can be found, it may also be possible to design marker-assisted breeding strategies for forest trees.     

Characterization of microsatellites in Fusicladium effusum,cause of pecan scab

Pecan scab, caused by the plant pathogenic fungus Fusicladium effusum, is the most destructive disease of pecan. Little is known of the population genetic diversity of this pathogen. In this study, microsatellites were mined from the F. effusum genome, and flanking primers were subsequently designed. A total of 275 microsatellites were screened, and 33 selected primers produced reliable, polymorphic markers against 46 isolates of F. effusum from 11 diverse locations in the southeastern USA. The number of alleles per microsatellite locus ranged from two to 17, and the polymorphic information content (PIC) from 0.475 to 0.911. A unique pattern informative combination (UPIC) analysis of three groups of 12 isolates each and 33 primers consistently showed a minimum number of markers required for the maximum discrimination of isolates equal to 3. The characteristics of the unique patterns (UP) and informative contents (IC) were very similar. However, the primers that were selected by UPIC were not necessarily the same for each of the three groups. Using all 46 isolates showed each locus was polymorphic, with a single‐population level Shannon's information index of 1.516, indicating substantial diversity. These markers show a range in polymorphic content and power of discrimination that will be valuable tools for studies of genetic diversity in F. effusum.