The cytology of tetraploid "Bromus inermis'' and the Co colchicine-induced octoploid

Abstract

A seed lot of Bromus obtained from the Botanic Garden of Novosibirsk, U.S.S.R., gave rise to fertile tetraploid plants, morphologically similar to natural octoploids of Bromus inermis. The cytology and morphology of this strain corresponds to that of a previously described tetraploid clone. The multivalent frequency in the Co generation of the colchicine-induced octoploids is significantly higher than that reported for natural octoploids. Possible explanations for this difference are discussed as it relates to the evolutionary origin of the natural octoploids.