The stability of isochromosomes

Abstract

[EN] The relative stability of the centromeres of an isochromosome and its original chromosome has been studied in the meiosis of subcompactoid wheat. The statistical analysis of the observations show that the isochromosome is provided with a centromere of normal strength and that its instability is due to its being an univalent and not to itself being an isochromosome. The possibility is suggested that there are two types of telocentrics: the stable telocentrics which arise through whole arm detection and the unstable ones which are produced by misdivision and can be transformed into isochromosomes by secondary misdivision.