engleski

Cytogenetic stability of Allium commutatum Guss. callus tissue

Callus tissue was derived from root-tips of in vitro grown Allium commutatum plantlets and maintained on MS medium containing 4.5 mM 2, 4-D and 4.6 mM kinetin. Influence of culture ageing and different concentrations of 2, 4-D and kinetin on morphogenetic and cytogenetic status was investigated. Callus tissue grown on MS medium without growth regulators was soft and whitish. It proliferated poorly and during subculturing numerous necrotic areas were observed. On media containing growth regulators callus tissue was yellowish, compact and nodular. The best proliferation was observed on media with both 2, 4-D and kinetin. Kinetin, especially when added in higher concentrations, resulted in a significant increase of mitotic index in short-term cultures. However, in long-term cultures kinetin had no significant influence on mitotic index. In calli grown on nutrient media containing 4.5 mM 2, 4-D and 4.6 mM kinetin, mitotic index in short- and long-term cultures was almost the same. Equimolar concentrations of 2, 4-D and kinetin favoured maintenance of undifferentiated cells. In callus interphase cells with different number of nucleoli (2-12) of equal or different size were observed. The number of cells with 3 or more nucleoli increased with culture ageing. Cytogenetic analysis showed low level of chromosomal abnormalities ; only few anaphase and telophase bridges and polyploid cells were noticed. The number of chromosomal abnormalities slightly increased during subculturing. Our investigations showed that A. commutatum callus tissue was relatively stable during long period of cultivating.

Allium commutatum Guss.; callus tissue; cytogenetic analysis

nije evidentirano