The level of genetic variability of cells in prolonged suspension culture of Arabidopsis thaliana

The level of heterogeneity and genetic variability of cells in a suspension of Arabidopsis thaliana cultured in vitro for more than seven years was studied. The considerable heterogeneity of the suspension in cell size was shown. As revealed by nuclear DNA cytophotometry, the suspension culture was mixoploid and the amount of DNA in the cells varied from 4 to 16 C. However, PCR with 6 RAPD- and 4 ISSR-primers and their intragroup combinations showed the lowest degree of variability of DNA markers. The genetic distances of clones obtained from a suspension culture of the parent plant were only 1.5%. Differences between the clones were identified with only one pair of 31 primer combinations tested, indicating low level of genetic heterogeneity of the suspension. The results showed that variations in the amount of DNA in the suspension culture cells are not accompanied by significant changes in the DNA sequence.