Abstract: Vicia faba seeds were treated with polysaccharide from Spirulina platensis before and after radiation. From the results of nuclear aberration frequency and types of chromosomal aberration in Vicia faba root tip ceils it is proposed that Spirulina p1antensis was a natural radioprotector. At a polysaccharide concentration of 0.1%–0.15%, radiation damage on Vicia faba could be reduced both in pretreated and posttreated groups. The effect of protection was more significant in posttreated group than in the pretreated one.

Key words: Spirulina platensis, Polysa chariede, Radioprotection, Root tip cells