IDENTIFICATION OF A STABLE MAINTAINER LINE FOR POLIMA CYTOPLASMIC MALE-STERILITY IN RAPESEED (BRASSICA-NAPUS L)

'Polima' cytoplasmic male sterility (CMS) was transferred to three dif ferent genotypes of B. napus i.e. GSL-1, ISN706 and HNS-8 by repeated backcrossing and was found to be completely stable in the nuclear back ground of synthetic B. napus genotype, ISN706, derived from a cross B. campestris ssp. oleifera var. brown sarson x B. oleracea var. botryti s cv. 'Pusa Katki'. The BCs and BC6 generation lines of ISN706, GSL-1 and HNS-8 with 'Polima' CMS were grown under a range of temperature an d photoperiod conditions to test their stability. No breakdown in ster ility was observed in 'Polima' ISN706 and, therefore, this genotype ca n be used as a maintainer for hybrid seed production.