Edaphic microsatellite DNA divergence in wild emmer wheat, Triticum dicoccoides, at a microsite: Tabigha, Israel

Twenty eight microsatellite markers were used to analyze genetic divergence in tandem dinucleotide repeated DNA regions between two edaphic subpopulat ions of Triticum dicoccoides growing on the contrasting terra rossa and bas alt soils from a microsite at Tabigha, north of the Sea of Galilee, Israel. The terra rossa soil niche was drier and more stressful than the basalt th roughout the growing season (November to May). Significant microsatellite d ivergence in allele distribution, repeat length, genetic diversity, and lin kage disequilibria were found between emmer wheat from the two soil types o ver two short transects of 100 m each. Soil-specific and -unique alleles an d linkage disequilibria were observed in the terra rossa and basalt subpopu lations. A permutation test showed that the effects of random genetic drift were very low for the significant genetic diversity at microsatellite loci between the two subpopulations, suggesting that an adaptive molecular patt ern derived by edaphic selection may act upon variation of the microsatelli tes.