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1.
Phellodendron amurense is an endangered tree with important medicinal and economic value in China. In this study, eight nuclear SSR primer pairs were employed to assess the genetic diversity and structure of 22 natural populations, including 516 individuals. A total of 66 alleles were detected with an average of 8.3 alleles per locus ranging from 3 to 17. The expected heterozygosity (He) of each SSR locus varied from 0.347 to 0.877 (average 0.627). Analysis of molecular variance (AMOVA) revealed that the main variation component existed within populations (95.11%) rather than among populations (4.89%). The Wilcoxon's sign-rank tests did not show any recent bottleneck effect in any population. A Mantel test displayed a significant correlation between the geographic distances and genetic distances for all populations (r = 0.566, P = 0.0001), indicating conformity to the isolation by distance model. Bayesian clustering and UPGMA supported grouping the populations into two groups. The present genetic structure of P. amurense may be explained by geographical isolation. The lack of genetic structure and genetic diversity decreased with increasing latitude within the Northeast China group may be due to postglacial northward expansion from a single refugium. Proper conservation measures are proposed for this species. 相似文献
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3.
U. Hohmann A. Graner T. R. Endo B. S. Gill R. G. Herrmann 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(4):618-626
Comparative genetic maps among the Triticeae or Gramineae provide the possibility for combining the genetics, mapping information and molecular-marker resources between different species. Dense genetic linkage maps of wheat and barley, which have a common array of molecular markers, along with deletion-based chromosome maps of Triticum aestivum L. will facilitate the construction of an integrated molecular marker-based map for the Triticeae. A set of 21 cDNA and genomic DNA clones, which had previously been used to map barley chromosome 1 (7H), were used to physically map wheat chromosomes 7A, 7B and 7D. A comparative map was constructed to estimate the degree of linkage conservation and synteny of chromosome segments between the group 7 chromosomes of the two species. The results reveal extensive homoeologies between these chromosomes, and the first evidence for an interstitial inversion on the short arm of a barley chromosome compared to the wheat homoeologue has been obtained. In a cytogenetically-based physical map of group 7 chromosomes that contain restriction-fragment-length polymorphic DNA (RFLP) and random amplified polymorphic DNA (RAPD) markers, the marker density in the most distal third of the chromosome arms was two-times higher than in the proximal region. The recombination rate in the distal third of each arm appears to be 8–15 times greater than in the proximal third of each arm where recombination of wheat chromosomes is suppressed. 相似文献
4.
Microsatellite DNA markers for rice chromosomes 总被引:45,自引:1,他引:44
H. Akagi Y. Yokozeki A. Inagaki T. Fujimura 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(7):1071-1077
We found 369 complete microsatellites, of which (CGG/GCC)n was the most frequent, in 11 798 rice sequences in the database. Of these microsatellites, 35 out of 45 could be successfully converted into microsatellite DNA markers using sequence information in their flanking regions. Thus, the time and labor used to develop new microsatellite DNA markers could be saved by using these published sequences. Twenty eight polymorphic markers between Asominori (japonica) and IR24 (indica) have been correctly mapped on the rice genome and microsatellites appear to be randomly distributed in the rice chromosomes. Integration of these markers with the published microsatellite DNA markers showed that about 35% of the rice chromosomes were covered by the 56 microsatellite DNA markers. These microsatellites were hypervariable and were easily to assay by PCR; they were distributed to all chromosomes and therefore, one can easily select plants carrying desired chromosome regions using these microsatellite DNA markers. Thus, microsatellite maps should aid the development of new breeds of rice saving time, labor, and money. 相似文献
5.
Martin WJ McCallum J Shigyo M Jakse J Kuhl JC Yamane N Pither-Joyce M Gokce AF Sink KC Town CD Havey MJ 《Molecular genetics and genomics : MGG》2005,274(3):197-204
The Poales (which include the grasses) and Asparagales [which include onion (Allium cepa L.) and other Allium species] are the two most economically important monocot orders. Enormous genomic resources have been developed for the grasses;
however, their applicability to other major monocot groups, such as the Asparagales, is unclear. Expressed sequence tags (ESTs)
from onion that showed significant similarities (80% similarity over at least 70% of the sequence) to single positions in
the rice genome were selected. One hundred new genetic markers developed from these ESTs were added to the intraspecific map
derived from the BYG15-23×AC43 segregating family, producing 14 linkage groups encompassing 1,907 cM at LOD 4. Onion linkage
groups were assigned to chromosomes using alien addition lines of Allium fistulosum L. carrying single onion chromosomes. Visual comparisons of genetic linkage in onion with physical linkage in rice revealed
scant colinearity; however, short regions of colinearity could be identified. Our results demonstrate that the grasses may
not be appropriate genomic models for other major monocot groups such as the Asparagales; this will make it necessary to develop
genomic resources for these important plants.
Electronic Supplementary Material Supplementary material is available for this article at 相似文献
6.
Inter simple sequence repeat (ISSR) analysis, using 14 primers was performed to estimate genetic diversity among 27 landraces of Hassawi rice growing in Al-Ahsa region of Saudi Arabia and deposited at King Abdulaziz City for Science and Technology with KACST IDs. The average polymorphism produced by 11 selected primers was more than 75%. The analysis of ISSR polymorphism divided the examined rice landraces into two groups; In one group (A), one accession (KACST 191) was clearly delimited as a distant landrace from other 12 landraces grouped in two clusters; cluster I of seven landraces of close geographic distributions; four of them grow at close geographic locations (KACST IDs 32, 183, 184, 185, 186, 187 and 188) and cluster II is comprised of five landraces KACST IDs (190, 308, 352, 353 and 355). In group B, the landraces were more closely related to each other as compared to the landraces of group A. In this group a small cluster of two landraces (KACST 305 & KACST 333) was clearly distant from a large group of three clusters comprised of landraces having KACST IDs 189 & 192, landraces 302, 306, 307, 308 & 310 and landraces with KACST IDs 334, 351, 354, 356 & 357 respectively. These results indicate that ISSR fingerprints are efficient in the identification and resolution of genetic diversity between the landraces of the Hassawi rice and will be an efficient method in the authentication of the rice germplasm in the gene bank of Saudi Arabia. 相似文献
7.
Y. Weng N. A. Tuleen G. E. Hart 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(3-4):519-527
Extended physical maps of chromosomes 6A, 6B and 6D of common wheat (Triticum aestivum L. em Thell., 2n=6x=42, AABBDD) were constructed with 107 DNA clones and 45 homoeologous group-6 deletion lines. Two-hundred and ten RFLP loci
were mapped, including three orthologous loci with each of 34 clones, two orthologous loci with each of 31 clones, one locus
with 40 clones, two paralogous loci with one clone, and four loci, including three orthologs and one paralog, with one clone.
Fifty five, 74 and 81 loci were mapped in 6A, 6B and 6D, respectively. The linear orders of the mapped orthologous loci in
6A, 6B and 6D appear to be identical and 65 loci were placed on a group-6 consensus physical map. Comparison of the consensus
physical map with eight linkage maps of homoeologous group-6 chromosomes from six Triticeaespecies disclosed that the linear
orders of the loci on the maps are largely, if not entirely, conserved. The relative distributions of loci on the physical
and linkage maps differ markedly, however. On most of the linkage maps, the loci are either distributed relatively evenly
or clustered around the centromere. In contrast, approximately 90% of the loci on the three physical maps are located either
in the distal one-half or the distal two-thirds of the six chromosome arms and most of the loci are clustered in two or three
segments in each chromosome.
Received: 19 April 1999 / Accepted: 28 July 1999 相似文献
8.
Characterization and analysis of microsatellite loci in Elymus caninus (Triticeae: Poaceae) 总被引:4,自引:0,他引:4
G.-L. Sun B. Salomon R. V. Bothmer 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(5):676-682
Microsatellites are highly variable DNA sequences that can be used as markers for the genetic analysis of plants. The potential
of microsatellite markers for use in a genetic diversity study in Elymus species was evaluated. Genomic libraries of Elymus caninus were constructed. The libraries were screened with two dinucleotide, (GA)n and (GT)n, and two trinucleotide repeats, (TCT)n
and (CAC)n. A total of 19 positive clones were found for the two dinucleotide repeats; no positive clone was found for the
trinucleotide repeats. Positive clones were sequenced to confirm the presence of microsatellites and to generate polymerase
chain reaction (PCR) primers based on the sequences flanking the microsatellite. All sequenced (GA)n clones have repeats of
n>10; over half of the (GT)n microsatellites have n<10 repeats. Primer pairs were designed and evaluated for 8 selected microsatellites. PCR products were amplified from 15
Elymus caninus accessions. The number of alleles found for the eight loci varied from 1 for ECGA89 and ECGT35 to 13 for ECGA22, as determined by non-denaturing polyacrylamide electrophoresis. Six microsatellite loci were found to be polymorphic in
E. caninus. The eight primer pairs were tested on three other species; seven were successful in amplifying DNA from Elymus alaskanus and E. mutabilis, and four amplified DNA from E. caucasicus. Based on these results, microsatellites appear to be useful markers in detecting variation in E. caninus.
Received: 8 September 1997/Accepted: 6 October 1997 相似文献
9.
D. E. Delaney S. Nasuda T. R. Endo B. S. Gill S. H. Hulbert 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1995,91(4):568-573
We have constructed cytologically based physical maps (CBPMs), depicting the chromosomal distribution of RFLP markers, of the group-2 chromosomes of common wheat (Triticum aestivum L. em Thell). Twenty-one homozygous deletion lines for 2A, 2B, and 2D were used to allocate RFLP loci to 19 deletion-interval regions. A consensus CBPM was colinearily aligned with a consensus genetic map of group-2 chromosomes. The comparison revealed greater frequency of recombination in the distal regions. Several molecularly tagged chromosome regions were identified which may be within the resolving power of pulsed-field gel electrophoresis. The CBPMs show that the available probes completely mark the group-2 chromosomes, and landmark loci for sub-arm regions were identified for targeted-mapping. 相似文献
10.
Marta Monteiro Conceio Santos Reinier M. Mann Amadeu M.V.M. Soares Tina Lopes 《Environmental and Experimental Botany》2007,60(3):421-427
Cadmium (Cd) is a non-essential element and is a widespread environmental pollutant. Exposure to cadmium can result in cytotoxic, carcinogenic and mutagenic effects. Mutagenesis is indicative of genetic instability and can be assayed using microsatellites. Microsatellites or simple sequence repeats (SSRs) are composed of tandem repeats of short sequence motifs (1–6 bp) that are polymorphic, mainly in the number of tandem repeated units. Therefore, chromosomic mutations like inversion, deletion or translocation and point mutations can be detected by this type of molecular marker. In this study we have evaluated the mutagenic/genotoxic effects of cadmium in lettuce (Lactuca sativa L.). Five-week-old lettuce plants grown in a modified Hoagland's medium were exposed for a further 14 days to a medium containing 100 μM Cd(NO3)2. Genomic DNA was extracted from lettuce leaves and roots, harvested at days 0, 1, 3, 7 and 14, and nine SSRs were tested, amplified and analysed to evaluate microsatellite instability (MSI). Mutagenic effects of cadmium on microsatellite DNA loci were assessed and no MSI was observed in the used markers. 相似文献
11.
Analysis of a sugarcane (Saccharum spp.) EST (expressed sequence tag) library of 8678 sequences revealed approximately 250 microsatellite or simple sequence repeats (SSRs) sequences. A diversity of dinucleotide and trinucleotide SSR repeat motifs were present although most were of the (CGG)n trinucleotide motif. Primer sets were designed for 35 sequences and tested on five sugarcane genotypes. Twenty-one primer pairs produced a PCR product and 17 pairs were polymorphic. Primer pairs that produced polymorphisms were mainly located in the coding sequence with only a single pair located within the 5′ untranslated region. No primer pairs producing a polymorphic product were found in the 3′ untranslated region. The level of polymorphism (PIC value) in cultivars detected by these SSRs was low in sugarcane (0.23). However, a subset of these markers showed a significantly higher level of polymorphism when applied to progenitor and related genera (Erianthus sp. and Sorghum sp.). By contrast, SSRs isolated from sugarcane genomic libraries amplify more readily, show high levels of polymorphism within sugarcane with a higher PIC value (0.72) but do not transfer to related species or genera well. 相似文献
12.
Comparative RFLP maps of the homoeologous group-2 chromosomes of wheat,rye and barley 总被引:11,自引:5,他引:6
K. M. Devos T. Millan M. D. Gale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1993,85(6-7):784-792
Summary Genetic maps of the homoeologous group-2 chromosomes were constructed, comprising 114 loci in wheat and 34 loci in rye. These include the genes coding for sucrose synthase, sedoheptulose-1,7-bisphosphatase, a bZIP protein (EmBP-1), a peroxidase and an abscisic acid-induced protein (#7). Overall, gene orders are highly conserved in the genomes of wheat, barley and rye, except for the distal ends of chromosome arms 2BS and 2RS, which are involved in interchromosomal, probably evolutionary, translocations. Clustering of loci in the centromeric regions of the maps, resulting from the concentration of recombination events in the distal chromosomal regions, is observed in wheat and rye, but not in barley. Furthermore, loci for which homoeoloci can be detected in rye and barley tend to lie in the centromeric regions of the maps, while non-homoeologous and wheat-specific loci tend to be more evenly distributed over the genetic maps. Mapping of the group-2 chromosomes in the intervarietal Timgalen x RL4137 cross revealed that the T. timopheevi chromosome segment introgressed into chromosome 2B in Timgalen is preferentially transmitted. Recombination is also greatly reduced in that segment. 相似文献
13.
Christiansen M.J. Andersen S.B. Ortiz R. 《Molecular breeding : new strategies in plant improvement》2002,9(1):1-11
Plant breeding may lead to narrowing genetic diversity of cultivatedcrops, thereby affecting sustained selection gains in crop improvement. A totalof 47 microsatellite primer pairs (mapped to the 21 wheat genetic linkagegroups) were assessed in 75 Nordic spring wheat cultivars bred during the20th century to determine the variation of genetic diversity in thisgermplasm throughout this period. The number of alleles ranged from one toseven, with an average of 3.6 alleles per microsatellite marker. A dendrogramresulting from analysis of the matrix of dissimilarities using the unweightedpair-group method with arithmetic average discriminated all cultivars andrevealed clusters of accessions released both from some geographical area inthe Nordic Region and the breeding era, i.e. before and after World War II. Geneticdiversity in this wheat material increased from 1900 to 1940 and again from1960 onwards. In between these two periods there was a loss of diversity, whichcould not be explained by changes in a single genome or in one or few chromosomesets. Effects of different selection within countries are revealed by cleardifferences in frequency of some microsatellite alleles. In adition somemicrosatellite alleles were lost during the first quarter of the century whileseveral new alleles were introduced in the Nordic spring wheat material duringthe second half of the century. These results suggest that genetic diversity inNordic spring wheat was enhanced by plant breeding in the first quarter of the20th century and following a decrease during the second quarter wasincreased again by plant breeding. 相似文献
14.
花生表型及SSR遗传多样性的研究 总被引:2,自引:0,他引:2
对山西省农业科学院经济作物研究所保存的75份花生材料(包括28个已审定的花生品种和47个地方品种)进行了包括株型、茸毛的有无、叶色、粒形、叶形、生长习性、开花习性、粒大小、粒色等表型性状的Shannon-Weaver遗传多样性指数(简称SWI)和Simpson遗传多样性指数(简称SI)分析。结果表明:参试的75份花生品种遗传多样性指数分别为SWI=0.924,SI=0.500,其中以开花习性最低(SWI=0.139,SI=0.014),而Shannon-Weaver指数以粒色最高为1.841,Simpson指数为0.712。利用48对SSR引物对这些材料进行了遗传多样性分析,结果如下:(1)在48对花生的SSR引物中,有35对(占所用引物总数的72.9%)具有多态性,共检测到215条多态性条带,平均每对引物可扩增6条多态性带。(2)根据SSR扩增结果对75份材料的聚类分析结果表明,这些材料的相似系数(GS)为0.25~0.85,平均GS值为0.55。28个审定品种的相似系数为0.39~0.85,平均为0.60。 相似文献
15.
Locating genotypes and genes for abiotic stress tolerance in barley: a strategy using maps, markers and the wild species 总被引:4,自引:1,他引:3
B. P. FORSTER J. R. RZUSSELL R. P. ELLIS L. L. HANDLEY D. ROBINSON C. A. HACKETT E. NEVO R. WAUGH D. C. GORDON R. KEITH W. POWELL 《The New phytologist》1997,137(1):141-147
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K. M. Devos M. D. Atkinson C. N. Chinoy C. J. Liu M. D. Gale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1992,83(8):931-939
Summary Genetic maps of chromosomes 3A, 3B and 3D of wheat and 3R of rye were developed using 22 DNA probes and two isozyme marker systems. Analysis of the 49 loci mapped showed extreme clustering around the centromere in all four maps, with large gaps in the distal chromosome regions, which is interpreted as being due to strong localisation of recombination towards the ends of the wheat and rye chromosomes. In the centromeric regions gene orders are highly conserved between the three wheat genomes and the rye genome. However, the unpredictable behaviour of the DNA clones that map in distal chromosome locations may indicate that the genomes are diverging most rapidly in the regions of higher recombination. A comparison of cDNA and genomic probes showed the latter to be much more efficient for revealing RFLP. Some classes of gDNA clones, i.e. chromosome-specific sequences and those hybridizing in a non-homoeologous manner, were seen to be most polymorphic. Correlations between map locations and RFLP levels showed no clear relationship. In addition to anonymous DNA clones, the locations of known function clones, sedoheptulose-1,7-bisphosphatase (XSbp), carboxypeptidase I (XCxp1) and a bZIP protein (XEmbp), were ascertained along with those for two isozyme loci, Mal-1 and Est-5. 相似文献
18.
RFLP-based genetic maps of wheat homoeologous group 7 chromosomes 总被引:23,自引:0,他引:23
S. Chao P. J. Sharp A. J. Worland E. J. Warham R. M. D. Koebner M. D. Gale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,78(4):495-504
Summary Restriction fragment length polymorphism (RFLP) mapping was attempted using 18 cDNA clones, 14 anonymous and 4 of known function, which had been shown to have homologous DNA sequences on the group 7 chromosomes of wheat. The loci identified by these probes have been mapped on one or more chromosomes in this homoeologous group using linkage data derived from various F2, random inbred, doubled haploid and single chromosome recombinant populations. The maps also include three isozyme loci, five disease resistance loci, two anthocyanin pigment loci and a vernalisation response locus. The mapping data have been used to determine the extent of map co-linearity over the A, B and D genomes, the degree of RFLP variability in the three genomes and the relative efficiency of various restriction enzymes in detecting RFLPs in wheat. The strategy for future mapping in wheat, particularly the use of alien genomes or segments, such as that from Aegilops ventricosa used here, is discussed. 相似文献
19.
Abundance, polymorphism and genetic mapping of microsatellites in rice 总被引:71,自引:0,他引:71
Dinucleotide microsatellites have been characterized and used as genetic markers in rice. Screening of a rice genomic library with poly(dG-dA)·(dC-dT) and poly(dG-dT)·(dC-dA) probes indicated that (GA)n repeats occurred, on average, once every 225 kb and (GT)n repeats once every 480 kb. DNA sequencing of ten randomly selected microsatellites indicated that the numbers of repeats ranged from 12 to 34 and that the patterns of microsatellites in rice were similar to those of humans and other mammals. Primers to these microsatellite loci as well as to four published microsatellite-containing sequences have been designed and degrees of polymorphism has been examined with 20 rice accessions. Multiple alleles, ranging from 5 to 11, have been observed at all the microsatellite loci in 20 rice accessions. Alleles specific to two cultivated subspecies, indica and japonica, were found in some microsatellite loci. Heterozygosity values of all the microsatellite markers were significantly higher than those of RFLP markers, based upon a parallel comparison. Ten microsatellite loci have been genetically mapped to four rice chromosomes. The genomic distribution of microsatellites appears to be random in rice. 相似文献
20.
Physical mapping of the Vrn-A1 and Fr1 genes on chromosome 5A of wheat using deletion lines 总被引:1,自引:0,他引:1
J. Sutka G. Galiba A. Vagujfalvi B. S. Gill J. W. Snape 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,99(1-2):199-202
Homozygous deletion lines of wheat for 5AL, generated in the variety ‘Chinese Spring’, were tested for flowering time without
vernalization and for frost resistance after cold hardening. It was found that the Vrn-A1 gene for vernalization requirement mapped between breakpoints 0.68 and 0.78, whilst the frost resistance gene Fr1 was flanked by deletion breakpoints 0.67 and 0.68. This confirms previous evidence that these genes are linked but are not
the pleiotropic effect of a single gene. A comparison between the physical and genetic maps for Vrn-A1 and Fr1 shows that the linear order is identical. These results indicate that cytogenetically based physical maps of Vrn-A1 and Fr1 loci, together with genetic maps, could be useful in the further study of genome synteny and in elaborating a gene cloning
strategy.
Received: 16 November 1998 / Accepted: 28 November 1998 相似文献