طرح ملی مطالعات جامع ژنتیکی گندمی ( گراس ها) موجود در بانک ژن و بررسی امکان تلاقی بین گونه ای بمنظور دستیابی به پتانسیل های موجود گونه های مختلف مرتعی

Eleven Bromus species were first studied in an observational field experiment. B. tomentellus and B. inermis were selected for complementary studies. Twelve plant populations of B. tomentellus, collected from different parts of the country, were studied for morphologic, phonologic and karyotypic characteristics. The data collected on the mentioned studies were analyzed first based on a separate statistical model. Then, when significant statistical differences were detected between the studied plant populations for the studied morphologic and karyotypic characteristics, the data were subjected to a complementary statistical analysis. The plant populations were classified based on the recorded different chromosome dimensions. Then correlations between the studied populations were investigated using the karyotypic characteristics. Cluster analysis was used to classify the studied plant populations using the morphologic and karyotypic characters. Then the populations with the most and the least similarity were detected. A number of karyotypic asymmetry measuring statistical parameters were estimated and the most symmetric and asymmetric karyotypes were identified. The plant populations were significantly different based on all of the studied morphologic characters. The studied populations and their chromosomes were also significantly different based on the recorded karyotypic characters. The two factors, plant populations and their chromosomes, showed significant interaction effects as well. The plant populations showed strong correlations based on chromosome total length. There were also significant differences between the populations based on long arm to short arm ratios. The dendrogram generated by cluster analysis performed on morphologic and karyotypic characteristics, didn't show quit a similar trend. The most distant populations based on the karyotypic characteristics, which are suspected to show karyotypic incompatibility in breeding projects by producing infertile progenies, were also detected. The most distant populations based on the morphologic characteristics, by which genetic variation may be increased in the breeding projects, were also introduced. Bromus inermis plant populations showed the best compatibility to the local climatic conditions. Therefore, the populations of the species with an average positive conditions based on the studied characters, was used to produce half-sib progenies for further studies. The half-sib progenies were planted in a field experiment to study its genetic architecture. It is worthwhile to mention that a mail-sterile genotype on which no anther was observed was also detected between the studied progenies. The phenomenon may be used in the future breeding projects. Parallel to the mentioned studies, all the studied Bromus species were evaluated for their karyotypic characteristics. Keywords: Genetic variation, Genetic architecture, Karyotype, Miosis, Multivariate analysis, Bromus.