Relationship Between the Chloroplast Number in Stomatal Guard Cells,

In this study for the first time the possibility of using stomatal guard cells chloroplasts counting and flow cytometry as a simple and easy alternative method for determining the ploidy level in Onobrychis was evaluated. Three randomly selected middle leaves of greenhouse grown plants were used for chloroplast counting in twenty pairs of stomatal guard cells per each leaf. Chromosome numbers were also determined in root tip squashes of studied plants. The ploidy level was highly correlated (r=0.95) with the number of chloroplast in stomatal guard cells of lower surface of the leaf. Number of chloroplasts in tetraploid species O. viciaefolia. And O. altissima was approximately twice as many as the number of chloroplasts in diploid species O. mazanderanica, O. amoena subsp. meshhedensis, O. amoena subsp. amoena , O. subnitens, O. schahuensis,O. chorassanica , O. michauxii and O. pulchella . With compare the peak and the ratio of mode of the control sample (O. amoena subsp. amoena) and the other samples, ploidy levels of samples were estimated and this ratio in tetraploid species was approximately twice as many as the ratio in diploids species. Our results suggest that these methods can successfully be used for determination of ploidy level in Onobrychis species .