Relationships among the A Genomes of Triticum L. Species as Evidenced by SSR Markers, in Iran

The relationships among 55 wheat accessions (47 accessions collected from Iran and eight accessions provided by the Institute of Plant Biology of the University of Zurich, Switzerland) belonging to eight species carrying A genome (Triticum monococcum L., T. boeoticum Boiss., T. urartu Tumanian ex Gandilyan, T. durum Desf., T. turgidum L., T. dicoccum Schrank ex Schübler, T. dicoccoides (Körn. ex Asch. & Graebner) Schweinf. and T. aestivum L.) were evaluated using 31 A genome specific microsatellite markers. A high level of polymorphism was observed among the accessions studied (PIC = 0.77). The highest gene diversity was revealed among T. durum genotypes, while the lowest genetic variation was found in T. dicoccoides accessions. The analysis of molecular variance (AMOVA) showed a significant genetic variance (75.56%) among these accessions, representing a high intra-specific genetic diversity within Triticum taxa in Iran. However, such a variance was not observed among their ploidy levels. Based on the genetic similarity analysis, the accessions collected from Iran were divided into two main groups: diploids and polyploids. The genetic similarity among the diploid and polyploid species was 0.85 and 0.89 respectively. There were no significant differences in A genome diversity from different geographic regions. Based on the genetic diversity analyses, we consider there is value in a greater sampling of each species in Iran to discover useful genes for breeding purposes

Phylogenetic comparison of the A genome using karyotype analysis in some Triticum species

The Karyotype analysis was performed on 46 wheat accessions belonging to five species (Triticum monococcum, T. urartu, T. durum, T. turgidum and T. aestivum) and two subspecies (T. boeoticum subsp. thaodar and T. boeoticum subsp. boeoticum) carrying A genome. All chromosomal sizes were measured with computer-aided program Micro Measure 3.3. Software. RL, TCL, MCL, arm ratio, centromeric index, TF%, mean of long and short arms, AsI%, S%, DRL, A1, A2 and karyotype formula were calculated for each chromosome. All the accessions were placed in 1A category of stebbines asymmetry categories. The scatter diagram based on A1 and A2 constructed three groups of karyotype asymmetry in the accessions studied: 1- T. aestivum with the highest asymmetrical karyotype, 2- T. monococcum, T. boeoticum subsp. thaodar and T. boeoticum subsp. boeoticum with the lowest asymmetrical karyotype and 3- T. urartu, T. turgidum and T. durum being with an intermediate between the two previous groups. T. monococcum based on the A1 and A2 index (asymmetric index) had the oldest and the most primitive karyotype among diploid species. According to the results, it might be suggested that T. durum is more primitive than T. turgidum and T. monococcum could be considered as a donor of A genome to T. durum and T. aestivum