Oil seed rape (Brassica napus L.) cultivars, donors of quality (SC) and self-incompatible (SI) lines have been analysed using identification of S-locus. In several Brassica napus cultivars one S-locus SLG gene was detected as dominant and the second S-locus as recessive. Amplification class II SLG gene screened recessive gene in all analysed samples (SC and SI). The DNA fragment of recessive gene corresponded to SLG gene W found in cv. Westar. S-haplotypes
were analysed by PCR-RFLP. Different Brassica napus cultivars had an identical electrophoretic profile conforming with nonfunctional A10 allele in B. campestris. In B. napus A10 allele is localised in genome A. The functional recessive SLG gene is probably localised in genome C. Model of their segregation was suggested. SC and SI plants
segregated in F2 generation at the ratio of approximately 3:1. This indicates a recessive monogenic disposition of SI in the experimental population.
