[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.

[Freezing of dehydrated calluses of spring wheat (Triticum aestivum L.) in liquid nitrogen and their morphogenetic potential].

A cryopreservation method developed earlier was modified for freezing the calluses derived from mature embryos of four spring wheat (Triticum aestivum L.) pure lines. The effects of individual stages of cryopreservation protocol on the water content, number of calluses resuming growth, and rate of morphogenesis were analyzed.

[Analysis of specific RAPD- and ISSR-fragments in somaclonal maize (Zea mays L.) and development of SCAR markers based on them].

RAPD (Random Amplified Polymorphic DNA) and ISSR (Inter Simple Sequence Repeats) markers were used to analyse the genetic divergence between the regenerated plants derived from callus cultures and the original maize line A188. Analysis of polymorphism by using 38 RAPD- and 10 ISSR-oligonucleotide primers showed that the differences between eight examined somaclones and the original line ranged from 6.5 to 23%.

[RAPD-analysis of corn somaclones].

The genetic difference between maize line A188 and A188-derived somaclones was assessed via analysis of randomly amplified polymorphic DNA (RAPD). In total, 15 out of 17 decanucleotide primers used each allowed amplification of 2-17 fragments ranging 200-2000 bp. The RAPD patterns did not differ between individual plants of line A188, which demonstrated again its high genetic homogeneity.