Genetic structure of wild emmer wheat populations as reflected by transcribed versus anonymous SSR markers.
Simple sequence repeat (SSR) markers have become a major tool in population genetic analyses. The anonymous genomic SSRs (gSSRs) have been recently supplemented with expressed sequence tag (EST) derived SSRs (eSSRs), which represent the transcribed regions of the genome. In the present study, we used 8 populations of wild emmer wheat (Triticum turgidum subsp. dicoccoides) to compare the usefulness of the two types of SSR markers in assessing allelic diversity and population structure. gSSRs revealed significantly higher diversity than eSSRs in terms of average number of alleles (14.92 vs. 7.4, respectively), polymorphic information content (0.87 vs. 0.68, respectively), and gene diversity (He; 0.55 vs. 0.38, respectively). Despite the overall differences in the level of diversity, Mantel tests for correlations between eSSR and gSSR pairwise genetic distances were found to be significant for each population as well as for all accessions jointly (RM=0.54, p=0.01). Various genetic structure analyses (AMOVA, PCoA, STRUCTURE, unrooted UPGMA tree) revealed a better capacity of eSSRs to distinguish between populations, while gSSRs showed a higher proportion of intrapopulation (among accessions) diversity. We conclude that eSSR and gSSR markers should be employed in conjunction to obtain a high inter- and intra-specific (or inter- and intra-varietal) distinctness.
Peleg
Zvi
Z
The Robert H. Smith Institute of Plant Science and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
Fahima
Tzion
T
Abbo
Shahal
S
Krugman
Tamar
T
Saranga
Yehoshua
Y
D000483:Alleles; D002874:Chromosome Mapping; D020224:Expressed Sequence Tags; D005819:Genetic Markers; D014644:Genetic Variation; D018745:Genome, Plant; D005838:Genotype; D018895:Microsatellite Repeats; D010641:Phenotype; D014908:Triticum / Q000235:genetics*
D005819:Genetic Markers