determination of ploidy levels of some populations of agropyron cristatum (poaceae) in iran by flow cytometry

flow cytometry (fcm) was used to determine the ploidy levels of six different populationsof agropyron cristatum (l.) gaertn. (poaceae) in iran, using a diploid cultivated barley (hordeumvulgare l.) as an internal reference. according to flow cytometric data, tetraploid (2n = ± 28) andhexaploid (2n = ± 42) levels were detected among the examined populations and these results weresupported by chromosome counting on the same materials included in this study. the mean nucleardna content (2c value) of the populations were then estimated, ranging from 26.41 to 27.56 pg for twovarieties of agropyron cristatum subsp. pectinatum, and 43.47 pg for agropyron cristatum subsp.incanum. the relationships between morphological variations observed among the taxa and ploidy levelswere also discussed.