CYTOGENETIC INVESTIGATIONS OF A CHLOROPHYLL MUTANT IN BROMEGRASS, BROMUS INERMIS LEYSS

Abstract
A dominant yellow mutant showed tetrasomic genetic ratios rather than disomic, hexasomic, or octosomic. Most mutant plants were simplex, a few were duplex or triplex. There were no quadruplex plants and a pure breeding yellow strain could not be formed. Chromosome segregation was more common than chromatid segrega-tion. Root-tip chromosomes showed a normal complement of 2n=56. Two chromosome pairs had large satellites and one pair has minute satellites. These observations confirm previous cytological evidence of an auto-alloploid derivation for the species.