RESEARCH ON THE DYNAMICS OF CELL DIVISION IN SOME LOCAL POPULATIONS OF SOLANUM TUBEROSUM L. FROM IN VITRO COLLECTION OF SUCEAVA GENEBANK

This study was conducted to analyze the cytogenetic effects induced by some growth inhibitors (daminozide, mannitol, and sorbitol) on cell division on five local varieties of potato from in vitro collection maintained by the Gene Bank of Suceava. We used four different culture media: medium of micromultiplication (control medium) - M14, medium with 30 mg/l daminozide - C22, the medium with 40 g/l mannitol - C23, the medium with 40 g/l sorbitol - C24. The effect of three substances on root meristems of genotypes analyzed was expressed as mitotic index, which ranged from 16,46% limits, the plantlets inoculated on medium with mannitol and 24,74% for the seedlings inoculated with daminozide medium. We observed a decrease in mitotic index in all five genotypes on mannitol and sorbitol medium and increase its on medium with daminozide. The studies showed that in most cells, regardless of culture medium used were normal mitosis. Were also found abnormal cell division, which included delayed, expelled and picnotic chromosomes, bridges and chromosomal fragments and micronuclei, but their percentage was lower in all genotypes, in all medium variations experienced.