Highly effective cell synchronization in plant roots by hydroxyurea and amiprophos-methyl or colchicine

Effective somatic cell synchronization in root-tip meristems and improved chromosome spreading were achieved in white campion, wheat, rye, and barley by application of hydroxyurea and amiprophos-methyl or colchicine, combined with a pretreatment of ice water and modified fixative, as well as enzymatic digestion of the meristems. The protocol provides metaphase indices of approximately 50%. The chromosomes and chromosomal DNA were with minimum distortion, providing useful material for chromosome banding studies, in situ DNA–DNA hybridization, microdissection, and microcloning.Key words: Melandrium album, rye, wheat, barley, cell cycle, root meristem, synchronization, metaphase index, chromosome preparation.