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Title: DEVELOPMENT OF SIMPLE SEQUENCE REPEAT (SSR)MARKERS AND THEIR USE IN STUDYING GENETIC VARIATION IN ALFALFA GERMPLASM.

Author
item HE, CHUNLIN - USDA-ARS BELTSVILLE
item Bauchan, Gary
item Campbell, Travis

Submitted to: International Symposium of Molecular Breeding of Forage Turf
Publication Type: Abstract Only
Publication Acceptance Date: 7/3/2005
Publication Date: 7/3/2005
Citation: He, C., Bauchan, G.R., Campbell, T.A. 2005. Development of simple sequence repeat (ssr)markers and their use in studying genetic variation in alfalfa germplasm.. International Symposium of Molecular Breeding of Forage Turf. Aberystwyth, Wales July 3-5, 2005. page 258.

Interpretive Summary:

Technical Abstract: Simple sequence repeat (SSR) markers are codominant and hypervariable molecular markers that are being widely used in genetic mapping, phylogenetic studies and marker-assisted selection. There are not many SSR markers available for use in alfalfa. Thus, this study was conducted to develop SSRs from alfalfa genomic libraries. Genomic DNA was isolated from the alfalfa germplasm W10 and libraries constructed with the vector pUC19 following restriction digest. Probes containing simple sequence repeats of CT, CAT, GAT, GTT were used for screening the colonies carrying inserts from the genomic libraries. The screening for CT repeats has been completed. In total 94 colonies with a positive signal were sequenced. Of the 94 sequences, 9 sequences did not contain any SSR, 11 were redundant and thus eliminated. Among the remaining 74 sequences, 31 could not be used for PCR primer design due to the terminal position presence of the SSR or unusable DNA sequence, thus 43 DNA sequences were used for primer design. After PCR testing, the vast majority (40) of the PCR primer pairs amplified the expected PCR fragments while the other three did not produce any PCR products. Based on preliminary screening using two parents from an alfalfa mapping project, 28(70%)of the 40 working primer pairs generated polymorphisms.