Abstract: Allele variation of ten low-polymorphic enzyme-encoding genes were analyzed among 349 accessions of Aegilops tauschii Coss., 183 of ssp. tauschii and 166 of ssp.strangulata (Eig) Tzvelev, representing all the species area. The data obtained indicated that both of these subspecies had originated and occupied their areas in ancient times. In ssp. tauschii and ssp. strangulata geographic occurrence of rare allozymes was sporadic and rather even through the subspecies areas. The probability of finding a rare allele of some of the ten loci studied in Ae. tauschii accession was also similar in the two subspecies and made up 0.066 and 0.060 for ssp. tauschii and ssp. strangulata, respectively. In both ssp. tauschii and ssp. strangulata an accession was found (k-1954 and t-9¹s, respectively) having more than one rare allele. Both accessions are of Caucasian origin, indicating that Ae. tauschii originated in this geographic region. Geographic distribution of rare allozymes occurrences reveals that genetic exchange between ssp. tauschii and ssp. strangulata takes place. Also this distribution indicates that in Ae. tauschii the same allozymes could have originated independently in different local populations: there are examples when the same rare allele was found in local populations located geographically very far from one another and belonging to different subspecies. Therefore it seems that the genetic system of Ae. tauschii local populations are in stochastic steady state. This makes this species a perfect model object for the studies of genetic basis of adaptive divergence.

Key words: Aegilops tauschii, allozymes, evolutionary history, genetic variation.