Pollen Mitosis in Induced-Tetraploid (2n=28) Crested Wheatgrass (Agropyron cristatum (L.) Gaertn.)

Authors: Ayşe Nihal GÖMÜRGEN

Abstract: The pollen mother cells (PMC) of an induced tetraploid (2n=28) Agropyron cristatum (L.) Gaertn. (which was obtained using colchicine treatment) stained with acetocarmine, the same method used in the analysis of meiosis. In this way there was no need to find a new method to observe the pollen mitosis. With these preparations it was possible to observe pollen mitotis just after the tetrad stage. In these observations chromosome counts could be made successfully since each PMC was discrete on the slide. Chromosome numbers constitute half of the 2n number in pollen mitosis, so counting the chromosome numbers is a simple process. Althogh it is well known that, in root-tip somatic cells, chromosome viscosity can be a hindrance to chromosome counting. However in this study, counting was carried out accurately through the use of pollen mitosis. In metaphase in pollen mitosis, well separated chromosomes were observed and the morphology was identified. In addition to this, young pollen with n=14, n+1 = 15, n-1 = 13 and n-2=12 chromosomes were found. These aneuploid cells were one of the results of the colchicine effects.

Keywords: Agropyron cristatum, pollen mitosis, aneuploidy.