A STABLE CYTOPLASMIC MALE-STERILE LINE OF BRASSICA-JUNCEA CARRYING RESTRUCTURED ORGANELLE GENOMES FROM THE SOMATIC HYBRID TRACHYSTOMA-BALLII -JUNCEA( BRASSICA)

A cytoplasmic male-sterile (CMS) line of Brassica juncea has been deve loped by combining the cytoplasm originating from the somatic hybrid T rachystoma ballii+B. juncea, and the nucleus of B. juncea cv. Pusa Bol d by repeated backcrossing. Male-sterile plants closely resembled the normal fertile B. juncea in general morphology, but had delayed flower ing (5-7 days) when compared with fertile 'Pusa Bold' which flowered i n 45 days. Stamens of the male-sterile line were transformed into peta loid structures. Pollen abortion occurred after tetrad formation. Fema le fertility of the male-sterile line was normal. Molecular analysis o f organelle genomes indicated extensive mitochondrial DNA recombinatio ns in the CMS line. Preliminary analysis of the chloroplast genome of the CMS line also indicated chloroplast DNA recombination.