The SLGs corresponding to the same S²⁴-haplotype are perfectly conserved in three different self-incompatible Brassica campestris L.

We have identified three strains of the same S²⁴-haplotype in self- incompatible B. campestris L. Two of them, S-12j and 1-1j, have been derived from Japanese populations and one, 27-1t, from Turkish one. The cDNA clones of SLG²⁴ (S²⁴-locus glycoprotein), which linked to the S-locus, were isolated from each strain, and sequenced. Each clone isolated from S-12j, 1- 1j and 27-1t, was designated as SLG²⁴ (S-12j), SLG²⁴ (1-1j) and SLG²⁴ (27-1t), respectively. Their nucleotide sequences were completely identical in coding region, 5' non-coding region, and 3' non-coding region, though the position of the polyadenylation site was slightly different among the cDNA clones. This result suggests that the origin of S²⁴-haplotype in these three strains might be common, and that the nucleotide sequences of SLG²⁴ of the same S²⁴-haplotype are completely conserved among different populations. The high conservation of the SLG²⁴ nucleotide sequences is probably essential for the recognition of self or non-self of self- incompatibility in this S²⁴-haplotype.