No abstract

Centaurea ragusina L. (Asteraceae) is an endemic Croatian plant species, which developed xeromorphic characteristics as a consequence of its natural environment -vertical limestone cliffs above the Adriatic sea. Cytogenetic status of C. ragusina long-term culture (94th subculture) and C. ragusina seedlings was analysed and compared after 4 weeks of growth. Cytogenetic stability was investigated in root meristem cells of C. ragusina cultured plants originated from Pend -a (cliffs near Dubrovnik) and seedlings originated from three different localities in south Adriatic (Pend -a, Pasjacˇa -cliffs near Dubrovnik and island of Komizˇa) using mitotic index and mitotic and chromosomal abnormalities as parameters. Mitotic indices of cultured plants and 'Pend -a' seedlings were similar and showed significant increase compared to mitotic indices of 'Komizˇa' and 'Pasjacˇa' seedlings. Although the highest number of mitotic abnormalities was recorded in root meristem cells of cultured plants, it was only a bit higher than in root tips of 'Pasjacˇa' and 'Pend -a' seedlings, while that of 'Komizˇa' was two times lower compared to cultured plants. Pattern of analysed mitotic abnormalities was very similar in root tips of cultured plants and 'Pasjacˇa' and 'Pend -a' seedlings, with exception of 'Komizˇa' seedlings. Presented results suggest that long-term cultivation of C. ragusina has almost no effect on culture ageing considering similar distribution of scored mitotic abnormalities as in 'Pend -a' and 'Pasjacˇa' seedlings.