CYTOGENETIC OBSERVATIONS ON SOME IN VITRO REGENERANTS PROVIDED BY OVARIES OF BRASSICA OLERACEA L. VAR. CAPITATA

The cytogenetic studies on in vitro-derived plants (by means of direct or indirect gynogenesis) – 6 genotypes of Brassica oleracea L. var. capitata, aimed to evince if and to what extent this type of conventional culture altered the mitotic cell division. There were some differences regarding the mitotic index, the distribution of cells on each phase of mitosis, and also on the percentage of abnormal ana-telophases. The gynogenetic shoots (Z2-12 genotype) obtained from callus on a culture medium supplemented with 1 ml-1 BAP and 0.1 ml-1 IAA displayed the highest mitotic index (51.74%), compared to the control (18.10%) and to the other studied vitroplants. The cytogenetic analysis of the shoots provided by direct organogenesis on several hormone variants (Z2-12 and TRM1 genotypes) evinced a decrease of the mitotic activity, compared to the control (18.10%). Regarding the cell distribution on mitotic phases, the highest percentage was registered by prophases, followed by metaphases, telophases and anaphases (in all the analyzed variants, including the control). The cytogenetic studies displayed a rather similar and high percentage of abnormal ana-telophases. The frequency of chromosomal abnormalities was significantly influenced by the presence of growth regulators in the culture medium and also by the genotype.