A COMPARATIVE CYTOLOGICAL STUDY IN THE D GENOME-BEARING SPECIES OF TRITICUM-AEGILOPS COMPLEX

The wild D genome-bearing Aegilops L. species. are considered to be sources of useful alleles which can be used in bread wheat improvement. We examined the karyotype asymmetry of the D genome-bearing species and analyzed the data to look for their evolutionary correlations. A total number of eleven accessions belonging to seven D genome species and Triticum aestivum L. were used for this study. The observations of the analyzed factors showed that Ae. vavilovii (Zhuk.) Chen. posses the most symmetric karyotypes and Ae. cylindrica Host. the most asymmetric ones. Both species Ae. crassa Boiss. and Ae. vavilovii carrying a common genomic formula (XD) showed a similar karyotype asymmetry. The results of this study compared with the literature showed that the degree of karyotype asymmetry of the D genome has a correlation with the time of divergence from its ancestral progenitors. Our results suggest that the karyotype asymmetry analysis can be a useful tool to have an overall view over the genomic relationships and modifications and also a good measure to estimate the relative date of the origin of allopolyploidy of the D genome cluster.