Cytological changes in callus cultures of Allium commutatum Guss.

Callus tissue was induced on root tips of in vitro cultured seedlings of Al lium commutatum Guss. cultured on MS medium supplemented with 4.6 mu M kine tin and 4.5 mu M 2,4-dichlorophenoxyacetic acid (2,4-D). Developed calli we re transferred to the same basal medium with addition of 1.0, 2.5 and 5.0 m u M 2,4-D or without 2,4-D. After three weeks in culture adventitious shoot and root induction was observed in compact greenish coloured callus on med ium without 2,4-D. On media supplemented with 1.0 and 2.5 mu M 2,4-D the ca llus was compact and yellowish with adventitious roots. No organogenesis wa s noticed on medium with 5.0 mu M 2,4-D and callus tissue was whitish and s limy. For preliminary cytological analyses samples of callus tissue were co llected on the 7. and 14. day after the transfer. Fixed calli fragments wer e hydrolized in 1 N HCl at 60 degrees C for 11 minutes and stained in tote with basic fuchsin. The slides were prepared according to standard Feulgen squash technique. In each sample 1000 cells were screened for mitotic activ ity and for establishing the rate of abnormalities. Relatively low level of genetic alterations was found, Among them micronuclei and polyploid cells were observed.