Genetic Correlation of Chromocentres and Chiasmata in some cultivated Crucifiers

摘要

Recently chromocentres have been identified as dark staining heteropycnotic bodies in the interphasic nuclei representing pericentric constitutive heterochromatin with varying number and size.(Lima de Faria and Taworska,1968;Nagl,1976). The chromocentres have now acquired special significance in chromosome pairing gene regulation, genetic recombination and evolution. Earlier studies on chromocentres demonstrated that the amount and distribution of constitutive heterochromatin are under polygenic control and depend on the heterozygosity of the material(Kumar,1997) The present study gives a comparative account of number and distribution of chromocentres and chiasmata in the cultivated crucifers in order to know whether an interrelationship exists between these nuclear characters.