Mahbubue Arabbeigi arabbeigy_20@yahoo.com 2009/03/01 Department of Agronomy and Plant Breeding Isfahan University of Technology, Isfahan 84156-83111, Iran Degree: M.Sc Language: Farsi Supervisor 1: Dr. A. Arzani a_arzani@cc.iut.ac.ir Supervisor 2: Dr. G. Saeidi gsaeidi@cc.iut.ac.ir To study the karyotype, meiotic behavior and NORs of wild, synthetic and common wheats, this research was conducted at Plant Breeding Laboratory of the Isfahan University of Technology. Twenty one genotypes including 10 wild wheat accessions, 7 common wheat genotypes and 4 synthetic hexaploid wheats were grown in the field. For meiotic studies, immature anthers containing pollen mother cell (PMC) were fixed in Carnoy solution and then stained with hematoxylin and finally squashed for microscopic observation. Overall, average number of ring bivalents at metaphase I ranged from 60% to 100% in the studied genotypes with the lowest rate belonging to diploid wild relative wheat species. Four meiotic abnormalities including precocious chromosome migration to the poles at metaphase, chromosome stickiness, laggard chromosomes at anaphase and telophase and formation of micronuclei in tetrad cells were found in the mentioned genotypes. The most meiotic abnormalities were found in synthetic wheat accessions, while meiotic index in all kind of wheat genotypes was more than 90% indicating their normal meiotic behavior. Analysis of mitotic metaphase chromosomes conducted via seed germination, pretreatment, fixation, storage, hydrolyzation, staining and observing under light microscope resulted in karyotype and ideogram. Results of analysis of variance showed that the wild, synthetic and common wheat populations possessed statistically significant variation in chromosomal characteristics including total chromosomal length, long and short arm lengths, arm ratio, centromery index and form percentage. Synthetic haxaploid wheat Altar84 / Ae. squarrosa (192) had the longest long arm (
