INHERITANCE OF RAPESEED (BRASSICA-NAPUS) SPECIFIC RAPD MARKERS AND A TRANSGENE IN THE CROSS BRASSICA-JUNCEA X (BRASSICA-JUNCEA X BRASSICA-NAPUS)

We have examined the inheritance of 20 rapeseed (Brassica napus)-speci fic RAPD (randomly amplified polymorphic DNA) markers from transgenic, herbicide-tolerant rapeseed in 54 plants of the BC1 generation from t he cross B. juncea x (B. juncea x B. napus). Hybridization between B. juncea and B. napus, with B. juncea as the female parent, was successf ul both in controlled crosses and spontaneously in the field. The cont rolled backcrossing of selected hybrids to B. juncea, again with B. ju ncea as the female parent, also resulted in many seeds. The BC1 plants contained from 0 to 20 of the rapeseed RAPD markers, and the frequenc y of inheritance of individual RAPD markers ranged from 19% to 93%. Th e transgene was found in 52% of the plants analyzed. Five synteny grou ps of RAPD markers were identified. In the hybrids pollen fertility wa s 0-28%. The hybrids with the highest pollen fertility were selected a s male parents for backcrossing, and pollen fertility in the BC1 plant s was improved (24-90%) compared to that of the hybrids.