Karyomorphological studies of ten strains of Indian mustard (Brassica juncea Coss.)

Summary Karyomorphological studies on ten cultivated strains of Brassica juncea Coss. (Indian mustard) have been made. All of them were found to possess 2n=36 chromosomes and meiotic studies revealed 18 regular bivalents. A great many structural differences between chromosome complements have been recorded. It has been shown that though homogeneous in gross morphology, minute structural differences between the strains are noted in relation to the number of secondary constrictions, the position of primary constrictions as well as the changes in the arm ratio. A histogram of the haploid chromatin complement of the somatic set of ten strains illustrates the differences.