HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Figures Only Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hu, G. Articles by Bonman, J. M. Search for Related Content PubMed Articles by Hu, G. Articles by Bonman, J. M. Agricola Articles by Hu, G. Articles by Bonman, J. M. Related Collections Oat Comparative Genomics Crop Genetics

GENOMICS, MOLECULAR GENETICS & BIOTECHNOLOGY

Expansion of PCR-based Marker Resources in Oat by Surveying Genome-Derived SSR Markers from Barley and Wheat

USDA-ARS, Small Grains and Potato Germplasm Research Unit, 1691 South 2700 West, Aberdeen, ID 83210

^* Corresponding author (gongsheh{at}uidaho.edu).

	ABSTRACT

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Identifying polymerase chain reaction (PCR)-based markers in crop genomes and amplifying them with specific primer pairs has provided convenient molecular markers for mapping projects. Oat (Avena sativa L.) lags behind other crops in the utilization of PCR-based markers due to limited development of genomic and genetic resources in Avena species. We surveyed 356 genome-derived simple sequence repeat (SSR) markers from wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), chosen on the basis of even dispersal across different chromosomes, to search for an alternate method of expanding the PCR-based marker pool in oat. Primer pairs for these SSR markers were tested for amplification and polymorphism between parental lines from Ogle1040/TAM-O-301 (OT) and Kanota/Ogle157 (KO) mapping populations. Eighty-nine of 210 wheat primer pairs (42%) and 56 of 146 barley primer pairs (38%) successfully amplified sequences in oat. Forty-five percent of the amplified markers, representing 19% of the total markers, showed polymorphism between parental lines of at least one mapping population. The polymorphism was primarily the presence or absence of a product band. Fifteen PCR products from 10 primer pairs were tested for reproducibility by amplifying each marker in the OT population. When assayed with the same PCR conditions used in the survey, the segregation ratio of 14 markers did not differ from the 1:1 ratio expected for a single locus. This study indicates that genomic SSR primer pairs from wheat and barley may be a good way to efficiently generate PCR-based DNA markers for oat genetics research.

Abbreviations: CTAB, cetyl trimethyl ammonium bromide • EST, expressed sequence tag • KO, Kanota x Ogle157 • OT, Ogle1040 x TAM-O-301 • PCR, polymerase chain reaction • RIL, recombinant inbred line • SSR, simple sequence repeat

Expansion of PCR-based Marker Resources in Oat by Surveying Genome-Derived SSR Markers from Barley and Wheat

USDA-ARS, Small Grains and Potato Germplasm Research Unit, 1691 South 2700 West, Aberdeen, ID 83210

^* Corresponding author (gongsheh{at}uidaho.edu).

Identifying polymerase chain reaction (PCR)-based markers in crop genomes and amplifying them with specific primer pairs has provided convenient molecular markers for mapping projects. Oat (Avena sativa L.) lags behind other crops in the utilization of PCR-based markers due to limited development of genomic and genetic resources in Avena species. We surveyed 356 genome-derived simple sequence repeat (SSR) markers from wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.), chosen on the basis of even dispersal across different chromosomes, to search for an alternate method of expanding the PCR-based marker pool in oat. Primer pairs for these SSR markers were tested for amplification and polymorphism between parental lines from Ogle1040/TAM-O-301 (OT) and Kanota/Ogle157 (KO) mapping populations. Eighty-nine of 210 wheat primer pairs (42%) and 56 of 146 barley primer pairs (38%) successfully amplified sequences in oat. Forty-five percent of the amplified markers, representing 19% of the total markers, showed polymorphism between parental lines of at least one mapping population. The polymorphism was primarily the presence or absence of a product band. Fifteen PCR products from 10 primer pairs were tested for reproducibility by amplifying each marker in the OT population. When assayed with the same PCR conditions used in the survey, the segregation ratio of 14 markers did not differ from the 1:1 ratio expected for a single locus. This study indicates that genomic SSR primer pairs from wheat and barley may be a good way to efficiently generate PCR-based DNA markers for oat genetics research.

Abbreviations: CTAB, cetyl trimethyl ammonium bromide • EST, expressed sequence tag • KO, Kanota x Ogle157 • OT, Ogle1040 x TAM-O-301 • PCR, polymerase chain reaction • RIL, recombinant inbred line • SSR, simple sequence repeat

	INTRODUCTION

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
SIMPLE SEQUENCE REPEATS (SSRs), or microsatellites, are abundant in plant genomes (Wang et al., 1994) and variations of the repeat number among different lines within a species occur at high frequency. These characteristics, along with an evenly dispersed genomic distribution, are properties which make SSRs ideal genetic markers (Morgante and Olivieri, 1993; Powell et al., 1996). In addition, the convenience and rapid assays accompanying SSR markers make them useful for a wide range of genetic and genomic applications (McCouch et al., 2002; Röder et al., 1995; Varshney et al., 2005). In oat (Avena sativa L.) there are currently few polymerase chain reaction (PCR)-based markers, including SSR types, available due to limited genomic sequence information.

The SSR markers are popular in species that are closely related to oat. In wheat (Triticum aestivum L.), over 2000 SSRs have been mapped (Eujayl et al., 2002; Gupta et al., 2002; Paillard et al., 2003; Pestsova et al., 2000; Röder et al., 1998; Somers et al., 2004; Song et al., 2005; Torada et al., 2006; Yu et al., 2004). La Rota et al. (2005) summarized over 9000 potential SSR sequences identified in wheat. Based on this information, it is expected that high density wheat SSR maps will be developed in the future. Similarly, over 400 SSR markers have been mapped in barley (Hordeum vulgare L.) (Li et al., 2003; Ramsay et al., 2000) and approximately 5000 additional candidate SSR markers exist (La Rota et al., 2005). In contrast, a small number of SSR markers have been mapped in oat (Jannink and Gardner, 2005; Li et al., 2000). A major disadvantage for identifying SSRs in oat compared to wheat and barley is the lack of genetic information available. This makes the development of SSR markers from the oat genome difficult.

A possible way to generate PCR-based markers in oat would be to use SSR primer pairs from related species such as barley and wheat. Jones et al. (2001) tested the amplification efficiency of SSR primer pairs from ryegrass (Lolium perenne L.) and found that 12% amplified in oat species. Li et al. (2000) tested 54 SSR primer pairs from barley on 12 wild oat species and 20 oat cultivars. Twenty-six percent (14 of 54) amplified distinguishable bands using an annealing temperature of 53°C. Gupta et al. (2003) reported that 24 of 59 (40.7%) wheat expressed sequence tag (EST)-SSR primer pairs successfully amplified fragments in five species, including oat. The objective of this study was to test the feasibility of using genomic SSR primer pairs from barley and wheat for large scale development of PCR-based marker in oat.

	MATERIALS AND METHODS

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
DNA Extraction
Seed of TAM-O-301, Ogle 1040, Kanota156, Ogle157 (Holland et al., 2001; Portyanko et al., 2001), and the 136 F6:10 Ogle/TAM-O-301 (OT) recombinant inbred lines (RIL) (Portyanko et al., 2001), were germinated on moistened filter paper in petri dishes incubated in a dark cabinet. After 5 d, approximately four coleoptiles per genotype were harvested and DNA was extracted using a cetyl trimethyl ammonium bromide (CTAB) protocol. In brief, each sample was frozen with liquid N and ground in a 2.0-mL eppendorf tube (Sigma, St. Louis, MO) with a sterile plastic pestle. Five hundred microliters of DNA extraction buffer (containing 140 mmol L^–1 sorbitol, 220 mmol L^–1 Tris, 22 mmol L^–1 EDTA, 800 mmol L^–1 NaCl, 0.8% CTAB, and 1.0% Sarcosine) was added to each tube and after incubation at 65°C, 300 µL of chloroform/isoamyl alcohol (24:1) was added. The solution was gently mixed, then centrifuged at 6000 g for 25 min. The resulting supernatant was added to an equal volume of chilled 70% isopropyl alcohol to precipitate the DNA. Using a sterile pipette tip, the precipitant was removed, washed with 70% ethanol, dried overnight, and resuspended in TE/RNase (1 µg mL^–1 DNase-free RNase) buffer.

PCR Amplifications and Scoring
Polymerase chain reaction amplifications were set up in a 96-well format. Each 25-µL reaction contained 60 ng of template DNA, 1 µL of each primer (10 µmol L^–1), 2.5 µL of 10x buffer, 1 µL of dNTPs with 2.5 mmol L^–1 concentration for each nucleotide, and 1 unit of Taq polymerase (RedTaq, Sigma). The PCR program was 94°C for 3 min followed by 39 cycles of 94°C for 30 s, 50°C for 30 s, and 72°C for 1 min, followed by a 4°C hold. Polymerase chain reaction products were analyzed on 6% nondenaturing polyacrylamide gels stained with ethidium bromide. Polymerase chain reaction amplification products that were consistent in two repeated PCR amplifications were scored for polymorphisms. The sizes of PCR products in oat were estimated using a DNA ladder (100-bp ladder, Bio-Rad, Hercules, CA) in the same gel.

SSR Primer Set Selection
We selected approximately 20 SSR primer pairs from each chromosome in the barley genome based on the major SSR marker maps (Li et al., 2003; Ramsay et al., 2000). Additional SSR or sequence tagged site primer pairs from chromosome 2 were also tested as they were available in our laboratory. Ten SSR primer pairs from each chromosome of the hexaploid wheat map (Somers et al., 2004) were selected to represent the individual chromosomes in the three wheat subgenomes. The criteria for SSR primer selection were to evenly cover as much of the genome as possible and to have publicly available sequence information. A total of 146 SSR primer pairs from barley and 210 from wheat were surveyed in this study. Detailed information for the selected SSR markers, including sequences, optimized PCR conditions, mapping locations, and sources, are available at the GrainGenes website (http://wheat.pw.usda.gov/GG2/index.shtml).

	RESULTS

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
Amplification of SSR Primers in Oat
Using DNA from the four oat parental lines, 55 of the 146 barley SSR primer pairs (38%) and 90 of the 210 wheat primer pairs (43%) produced reproducible PCR products in two separate PCRs. Amplification frequencies were also calculated from each barley chromosome, wheat subgenome, and respective chromosomes of the different wheat subgenomes. Although the numbers of SSR primers from each chromosome whose primer pairs were tested in oat were too few to provide rigorous statistical comparisons, the results indicated that variation may exist among amplification frequencies with SSR primer pairs from different barley chromosomes and wheat subgenomes (Table 1 ). For instance, the frequency of barley SSR primer set amplification in oat ranged from 15% for sets from chromosome 7 to 56% for sets from chromosome 6. The overall amplification frequencies in oat of SSR primer pairs selected from wheat differed among the subgenomes with genome A (50%) > genome B (44%) > genome D (34%) (Table 1). As with the primer pairs selected from different barley chromosomes, amplification frequencies in oat appeared to vary among primer pairs from different wheat chromosomes in the same subgenome. For example, in wheat genome B, 20% of SSR primer pairs from chromosome 1 and 70% of the primer pairs from chromosome 2 yielded PCR products in oat. If SSR markers from barley and wheat are equally amplified in oat, we should see an even distribution of amplified markers along a chromosome. However, markers amplified by SSR primers from both barley (Fig. 1 ) and wheat (Fig. 2 ) were not evenly distributed based on the SSR location in some of the chromosomes. For example on the short arm of barley chromosome 2 (Ramsay et al., 2000), only one primer pair out of eight selected between Bmac0314 and EBmac0715 representing 43 cM genetic distance (from position 5 to position 48 in the map from Ramsay et al., 2000) amplified in oat. In contrast, six out of nine primer pairs between HvXan and EBmag0793 covering about the same distance (from position 54 to position 95) on the long arm of chromosome 2 amplified in oat (Fig. 1). Although these results suggest that certain locations in the barley and wheat genomes are more likely to provide markers applicable to oat, more markers must be tested to confirm this hypothesis.

View larger version (52K): [in this window] [in a new window]   Figure 1. Distribution of simple sequence repeat (SSR) primers selected from barley. Distances between markers do not reflect the exact map positions. Primer pairs in bold letters produced positive polymerase chain reaction (PCR) products in oat lines.

View larger version (39K): [in this window] [in a new window]   Figure 2. Distribution of simple sequence repeat (SSR) primers selected from wheat. Distances between markers do not reflect the exact map positions. Primer pairs in bold letters produced positive polymerase chain reaction (PCR) products in oat lines. Numbers at the top represent the specific chromosomes. A, B, and D after each number designate the different subgenomes of the chromosomes. Marker Barc59 is indicated on both chromosomes 5B and 2D.

Amplification and Relationship between the Repeat Sequences of SSR Markers
To determine if there was a relationship between motif sequence in the donor species SSRs and whether the primer set produced amplification in oat, we summarized the SSR sequence composition in the selected markers and calculated the percentage of each sequence type producing amplified products in oat. Results were derived from 132 of the 146 barley markers because motif information for 14 markers was unavailable. Barley primer pairs most frequently producing amplification in oat were those targeting the motifs AC/TG, AG/TC, CT/GA, and CA/GT (Table 3 ). These targeted motifs accounted for 89% (117/132) of the total, which was expected since they were the most tested. Motif information was available for 186 of 210 wheat SSR markers. Primer pairs most frequently producing amplification in oat were CA/GT, CT/GA, AC/TG, and ATT/TAA, accounting for 91% (169/186) of the total (Table 3). The primer pairs for the motif CT/GA from both barley and wheat showed a high frequency of PCR amplification in oat. However, primer pairs amplifying barley markers with the AC/TG repeat sequence showed a high amplification frequency (41%) in oat whereas those for wheat SSRs with the same motif showed no amplification in oat (Table 3). This result indicates that there is no useable correlation between the motif of the marker in the donor and amplification in oat.

A high level of polymorphism was detected between Ogle1040 and Ogle157. Seventeen primer pairs produced different PCR profiles between these two Ogle lines. Some primers produced additional fragments in one of the two lines. For example, Bmac213 showed an extra 400-bp fragment in Ogle1040 in addition to the 290-bp common fragment (Table 5). Other primer pairs, such as Bmag375, produced totally different amplification profiles in the two Ogle lines. The amplification profile of Bmag375 shows three fragments of 150, 280, and 300 bp in Ogle1040, but two fragments of 500 and 700 bp in Ogle157. Such results, with 26% (17/66) of primers producing polymorphisms in the two Ogle lines, may reflect either the highly complex nature of the oat genome or heterogeneity in the original cultivar. Our results support those of Fox et al. (2001), who found 10 of 66 restriction fragment length polymorphism banding patterns differed between single plant selections from Ogle. They concluded that genetic variability within the original cultivar was responsible for the differences.

Testing the Polymorphic PCR Products in the Oat Mapping Population under the Screening PCR Conditions
The 50°C annealing temperature in the marker screening experiment is lower than the optimized annealing conditions for most SSR primer pairs in the species from which they originated. To test the reproducibility of PCR products produced in this study, 10 primer pairs that produced polymorphic markers between TAM-O-301 and Ogle1040 were randomly selected for testing on the OT RIL population (Table 6 ). Among the 15 PCR products tested, 14 segregated in a 1:1 ratio as did the control marker AM112 (Table 6). Three of the PCR products were codominant markers. Thus, most of the polymorphic PCR products derived from barley and wheat SSR primers sets are useful markers that could be mapped in the same way as the oat sequence-derived PCR markers.

	DISCUSSION

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

The majority of SSR primer pairs in our study yielded good quality PCR products that were easily scored. In addition to those products, there were also some weakly amplified fragments (Fig. 3 ). Most of this background amplification was likely due to the generalized PCR parameters. It was necessary to use a single PCR condition for all the primer pairs in the survey due to the large number of primers to be tested. It was thus not practical to optimize amplification conditions for each primer in the survey, but such optimization will be possible in subsequent work aimed at mapping these markers. Another important discovery in this study is that the polymorphic PCR products scored at 50°C annealing temperature are mappable under the same PCR condition (Table 6). Detection and mapping of the PCR products at the same lower annealing temperature as that used in screening may be a good approach to enrich PCR-based markers in oat because the relaxed PCR condition allows partially homologous primers to amplify products. After sequencing such products, primers could be redesigned to create better PCR-based markers for oat.

View larger version (100K): [in this window] [in a new window]   Figure 3. Example of marker production profiles of four primer pairs in oat. The primer pairs were from barley; polymerase chain reaction (PCR) products were separated on a 6% polyacrylamide gel. The first lane is a 100-bp ladder. T, TAM-O-301; O1, Ogle1040; K, Kanota156; O2, Ogle157.

The transferability of markers from a donor genome depends on sequence conservation in specific regions of the recipient genomes where the primers are located. Our study showed that transferability rates might vary in different regions within the same donor genome. For example, amplification rates of SSR primers from the long arms of wheat chromosomes 4D and 6A appeared higher than those from the long arms of 1B and 7B (Fig. 2). For the practical purpose of enriching PCR-based markers in oat, the transfer rates from wheat and barley are acceptable and may be further improved if we can confirm that some subgenomes have higher transfer frequencies, and then select SSR primer pairs for testing based on this information. Despite some possible difference in transferability frequency for barley and wheat markers, the large number of available SSR primer sequences from these two species is a rich resource for oat marker generation.

In addition to genomic SSR markers, EST-derived SSR markers from other species may be another useful source for oat PCR-based marker development. In general, EST-SSR markers have a higher transferability across species than do genomic markers, while genomic SSR markers are more polymorphic. EST-SSR markers originate in coding sequences that are more conserved during evolution compared to genomic sequences. Direct comparisons of polymorphic rates between genomic SSR and EST-SSR markers have been reported (Gonzalo et al., 2005; Torada et al., 2006). In wheat, 46% of genomic SSR markers detected polymorphisms in nine cultivars while only 34% of EST-SSR markers detected polymorphisms in the same cultivars (Torada et al., 2006). Gupta et al. (2003) reported that 24 of 64 wheat EST-SSR primer pairs amplified fragments in oat using unspecified PCR conditions. Thus, the transfer frequency of the genome derived SSRs from our study appears to be higher than that of wheat EST-SSRs (Gupta et al., 2003).

Cultivated oat has a large genome with an estimated size of 13,000 Mb (Bennett and Smith, 1976) and highly rearranged genomic structures (Hayasaki et al., 2000). The complexity of the oat genome could affect the detection of polymorphic molecular markers. Most of the oat PCR-based markers identified in the present study are of the dominant type. Our results showed that at least 63 to 80% (Table 5) of markers are dominant; that is, either present in one line and absent in another or amplifying extra products in one of the two parental lines. We are not aware of such a high percentage of dominant markers in any other plant species, at least for SSR sequence-based markers. One possible explanation for the high frequency of dominant marker is that some of the PCR products derived from SSR primer pairs are actually random amplified polymorphic DNA markers. Another explanation is that possible imperfect duplication of sequences in the oat genome created multiple binding sites resulting in extra PCR fragments in some genotypes. Sequencing of the dominant fragments may help to understand the nature of the dominant PCR products. Additional evidence of genomic complexity in oat is the relatively high polymorphism rate between parental lines from two sources of the same cultivar Ogle. Nineteen percent of polymorphic markers identified in our experiment detected polymorphisms between Ogle1040 and Ogle157 even though they are both derived from the same cultivar of Ogle. For a self-pollinated species, this percentage is surprisingly high between lines presumably derived from the same cultivar.

In summary we surveyed 356 SSR primer pairs from both wheat and barley for their ability to amplify DNA fragments in oat. Approximately 40% yielded PCR-based markers. Forty-five percent of the amplified markers detected polymorphisms between parental lines of two oat mapping populations and 14 of 15 produced expected segregation ratios in the OT mapping population. The results of this study illustrate that wheat and barley are good genetic resources for marker development in oat. The results also point to the potential for future utilization in oat of other types of DNA markers, such as single nucleotide polymorphisms, from barley and wheat.

	ACKNOWLEDGMENTS

 
We thank Mr. Robert Campbell for his technical assistance and Dr. Donald Obert and Dr. Phil Bregitzer for their critical review of the manuscript.

	NOTES

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher.

Received for publication December 29, 2006.

	REFERENCES

TOP NOTES ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 

• Bennett, M.D., and J.B. Smith. 1976. Nuclear DNA amounts in angiosperms. Philos. Trans. R. Soc. London B 274:227–274.[Web of Science][Medline]
• Eujayl, I., M.E. Sorrells, M. Baum, P. Wolters, and W. Powell. 2002. Isolation of EST-derived microsatellite markers for genotyping the A and B genomes of wheat. Theor. Appl. Genet. 104:399–407.[CrossRef][Web of Science][Medline]
• Fox, S.L., E.N. Jellen, S.F. Kianian, H.W. Rines, and R.L. Phillips. 2001. Assignment of RFLP linkage groups to chromosomes using monosomic F1 analysis in hexaploid oat. Theor. Appl. Genet. 102:320–326.[CrossRef][Web of Science]
• Gonzalo, M.J., M. Oliver, J. Garcia-Mas, A. Monfort, R. Dolcet-Sanjuan, N. Katzir, P. Arus, and A.J. Monforte. 2005. Simple-sequence repeat markers used in merging linkage maps of melon (Cucumis melo L.). Theor. Appl. Genet. 110:802–811.[CrossRef][Web of Science][Medline]
• Gupta, K., S. Balyan, J. Edwards, P. Isaac, V. Korzun, M. Röder, and M.F. Gautier. 2002. Genetic mapping of 66 new microsatellite (SSR) loci in bread wheat. Theor. Appl. Genet. 105:413–422.[CrossRef][Web of Science][Medline]
• Gupta, P.K., S. Rustgi, S. Sharma, R. Singh, N. Kumar, and H.S. Balyan. 2003. Transferable EST-SSR markers for the study of polymorphism and genetic diversity in bread wheat. Mol. Genet. Genomics 270:315–323.[CrossRef][Web of Science][Medline]
• Harvey, B.L., and G.G. Rossnagel. 1984. Harrington barley. Can. J. Plant Sci. 64:193–194.
• Hayasaki, M., T. Morikawa, and I. Tarumoto. 2000. Intergenomic translocations of polyploid oats (genus Avena) revealed by genomic in situ hybridization. Genes Genet. Syst. 75:167–171.[CrossRef][Web of Science][Medline]
• Holland, J.B., S.J. Helland, N. Sharopova, and D.C. Rhyne. 2001. Polymorphism of PCR-based markers targeting exons, introns, promoter regions, and SSRs in maize and introns and repeat sequences in oat. Genome 44:1065–1076.[Medline]
• Jannink, J.L., and S.W. Gardner. 2005. Expanding the pool of PCR-based markers for oat. Crop Sci. 45:2383–2387.[Abstract/Free Full Text]
• Jones, E.S., M.P. Dupal, R. Kolliker, M.C. Drayton, and J.W. Forster. 2001. Development and characterisation of simple sequence repeat (SSR) markers for perennial ryegrass (Lolium perenne L.). Theor. Appl. Genet. 102:405–415.[CrossRef][Web of Science]
• La Rota, R.M., R.V. Kantety, J.K. Yu, and M.E. Sorrells. 2005. Nonrandom distribution and frequencies of genomic and EST-derived microsatellite markers in rice, wheat, and barley. BMC Genomics 6:23–35.[CrossRef][Medline]
• Li, C.D., B.G. Rossnagel, and G.J. Scoles. 2000. The development of oat microsatellite markers and their use in identifying relationships among Avena species and oat cultivars. Theor. Appl. Genet. 101:1259–1268.[CrossRef][Web of Science]
• Li, J.Z., T.G. Sjakste, M.S. Röder, and M.W. Ganal. 2003. Development and genetic mapping of 127 new microsatellite markers in barley. Theor. Appl. Genet. 107:1021–1027.[CrossRef][Web of Science][Medline]
• McCouch, S.R., L. Teytelman, Y. Xu, K.B. Lobos, K. Clare, M. Walton, and B. Fu. 2002. Development and mapping of 2240 new SSR markers for rice (Oryza sativa L.). DNA Res. 9:199–207.[Abstract]
• Morgante, M., and A.M. Olivieri. 1993. PCR-amplified microsatellites as markers in plant genetics. Plant J. 3:175–182.[CrossRef][Web of Science][Medline]
• Paillard, S., T. Schnurbusch, M. Winzeler, M. Messmer, P. Sourdille, O. Abderhalden, B. Keller, and G. Schachermayr. 2003. An integrative genetic linkage map of winter wheat (Triticum aestivum L.). Theor. Appl. Genet. 107:1235–1242.[CrossRef][Web of Science][Medline]
• Pal, N., J.S. Sandhu, L.L. Domier, and F.L. Kolb. 2002. Development and characterization of microsatellite and RFLP-derived PCR markers in oat. Crop Sci. 42:912–918.[Abstract/Free Full Text]
• Pestsova, E., M.W. Ganal, and M.S. Röder. 2000. Isolation and mapping of microsatellite markers specific for the D genome of bread wheat. Genome 43:689–697.[Medline]
• Portyanko, V.A., D.L. Hoffman, M. Lee, and J.B. Holland. 2001. A linkage map of hexaploid oat based on grass anchor DNA clones and its relationship to other oat maps. Genome 44:249–265.[Medline]
• Powell, W., G.C. Marchray, and J. Provan. 1996. Polymorphism revealed by simple sequence repeats. Trends Plant Sci. 1:215–222.[Web of Science]
• Ramsay, L., M. Macaulay, S. degli Ivanissevich, K. MacLean, L. Cardle, J. Fuller, and K.J. Edwards. 2000. A simple sequence repeat-based linkage map of barley. Genetics 156:1997–2005.[Abstract/Free Full Text]
• Röder, M.S., V. Korzun, K. Wendehake, J. Plaschke, M.H. Tixier, P. Leroy, and M.W. Ganal. 1998. A microsatellite map of wheat. Genetics 149:2007–2023.[Abstract/Free Full Text]
• Röder, M.S., J. Plaschke, S.U. Konig, A. Borner, M.E. Sorrells, S.D. Tanksley, and M.W. Ganal. 1995. Abundance, variability and chromosomal location of microsatellites in wheat. Mol. Gen. Genet. 246:327–333.[CrossRef][Web of Science][Medline]
• Somers, D.J., P. Isaac, and K. Edwards. 2004. A high-density microsatellite consensus map for bread wheat (Triticum aestivum L.). Theor. Appl. Genet. 109:1105–1114.[CrossRef][Web of Science][Medline]
• Song, Q.J., J.R. Shi, S. Singh, E.W. Fickus, J.M. Costa, J. Lewis, B.S. Gill, R. Ward, and P.B. Cregan. 2005. Development and mapping of microsatellite (SSR) markers in wheat. Theor. Appl. Genet. 110:550–560.[CrossRef][Web of Science][Medline]
• Torada, A., M. Koike, K. Mochida, and Y. Ogihara. 2006. SSR-based linkage map with new markers using an intraspecific population of common wheat. Theor. Appl. Genet. 112:1042–1051.[CrossRef][Web of Science][Medline]
• Varshney, R.K., A. Graner, and M.E. Sorrells. 2005. Genic microsatellite markers in plants: Features and applications. Trends Biotechnol. 23:48–55.[CrossRef][Web of Science][Medline]
• Wang, Z., J.L. Weber, G. Zhong, and S.D. Tanksley. 1994. Survey of plant short tandem DNA repeats. Theor. Appl. Genet. 88:1–6.[Web of Science]
• Wight, C.P., N.A. Tinker, S.F. Kianian, M.E. Sorrells, L.S. O'Donoughue, D.L. Hoffman, and S. Groh. 2003. A molecular marker map in ‘Kanota’ x ‘Ogle’ hexaploid oat (Avena spp.) enhanced by additional markers and a robust framework. Genome 46:28–47.[Medline]
• Yu, J.K., M. La Rota, R.V. Kantety, and M.E. Sorrells. 2004. EST derived SSR markers for comparative mapping in wheat and rice. Mol. Genet. Gen. 271:742–751.[Web of Science][Medline]
• Zhang, L.Y., M. Bernard, P. Leroy, C. Feuillet, and P. Sourdille. 2005. High transferability of bread wheat EST-derived SSRs to other cereals. Theor. Appl. Genet. 111:677–687.[CrossRef][Web of Science][Medline]

This Article Abstract Figures Only Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hu, G. Articles by Bonman, J. M. Search for Related Content PubMed Articles by Hu, G. Articles by Bonman, J. M. Agricola Articles by Hu, G. Articles by Bonman, J. M. Related Collections Oat Comparative Genomics Crop Genetics