The materials consisted of field collections (Fig. 1) made as seed accessions and herbarium specimens, or the herbarium specimens from different herbaria of Iran (Table 2). Taxonomic studies were performed on both herbarium specimens and the field materials. Each accession was provided with a voucher specimen deposited at the herbarium of Isfahan University.
In order to gain a general idea of the morphological characters in the genus, 160 morphological characters were studied. Of these, eight quantitative and qualitative characters were selected as the most informative ones for this study. The characters studied are listed in Table 3. Morphological descriptions are based on Bor (1970) and Steam(1983). For flag leaf width and length, 30 individuals for each population were examined. Mean and cv. (coefficient of variation) were calculated for each species. In order to avoid misidentifications caused by the deficiency of taxonomic descriptions and poorly constructed keys, particularly in the case of T. aestivum, T. turgidum and T. durum, a cytotaxonomic survey was performed on all accessions examined in this study. For each accession 1-3 root tips were studied (Waines and Kimber 1973; Lange and Jochemzen 1992).
The names and authorities of the diploid species and of T. dicoccoides are taken from Van Slageren (1994), and those of the tetraploid and hexaploid species from Bor (1970). Drawings are based on the herbarium sheets deposited in the herbarium of Isfahan University (Fig. 2); the code number of each sheet used for drawing is designated as Tr- followed by the number of wheat collection in the above herbarium.