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Journal of Applied Genetics 42(1), 2001, pp. 21-32

Karyological characterization of sugar beet gynogenetic lines cultured in vitro


Abstract: Flow cytometry was used to screen ploidy levels in 47 cultured in vitro sugar beet gynogenetic lines of various origin and age, obtained after plant regeneration from unfertilized ovules. When donor plants were diploid, the majority of regenerants were found to have cells with 1C, 2C and 4C relative DNA content (mainly haploid and diploid) and there were large differences in the rate of spontaneous in vitro chromosome doubling between individual homozygous lines. Six ovule-derived lines regenerated from fertile and sterile diploid donors of forty-five lines were solid diploids from the very early stages of their in vitro cultivation, and thus could not be classified as doubled haploids. In the case of tetraploid donor plants, the gynogenetic regenerants demonstrated 2x-ploidy level. The results obtained in chimeric plants with both haploid and diploid cells indicated the possibility to overcome mixoploidy by their re-cultivation through generative shoot tip culture. The flow cytometry method confirmed data obtained by conventional microscopic chromosome counting in dividing leaf cells and was found very useful for screening of a large number of regenerants and for characterizing the process of in vitro gynogenetic lines formation in sugar beet.

Key words: Flow cytometry, DNA content, ploidy, sugar beet, gynogenetic lines, chromosome doubling, doubled haploids.

Correspondence: A. Svirshchevskaya, Institute of Genetics and Cytology, Belarus National Academy of Sciences, Akademicheskaya 27, 220072 - Minsk, Republic of Belarus.