Bijay Shankar Singha* & N. Dayalb
aCambridge Institute of Technology, Tatisilwai, Ranchi.
bDept. of Botany, Ranchi University, Ranchi, Jharkhand, India.
Received 5th August 2007; Revised 2nd September 2007
Abstract : Species of Raphanus, both wild and cultivated, are diploid (2n = 18). They have probably evolved us secondarily balanced polyploids from a common archetype having 12 chromosomes (x = 6). Raphanobrassica1 and Brassicoraphanus are synthetic artificial allopolyploids, used as genetic bridge for transfer of genes from one genus to another. They have also been exploited for genome substitution and may be used as genetic bridge for transfer of genes from one genus to another thus constituting an important tool in the hands of the plant breeders for the germplasm improvement in radish and brassicas. Use of colchicine induced polyploids in plant breeding may be quite rewarding as has been shown in this root crop earlier in Japan and recently by us in India2.