Identification of S-haplotypes in DH-lines of broccoli (Brassica

摘要

Self-incompatibility (SI) in broccoli (Brassica oleracea L. var. italica) is common, and controlled by the S-locus which contains at least three genes: SLG (the S-locus glycoprotein), SRK (the S-locus receptor kinase), and SCR (the S-locus cysteine-rich protein) also named SP11 (the S-locus protein 11). As the S-locus is complex, the classical term 'S-allele' was changed to `S-haplotype'. Information on S-alleles in breeding lines is important for breeders to ensure cross-compatibility between lines. In this work, the S-haplotypes of 18 dihaploid (DH) broccoli lines were examined. For each line, fragments of the SRK and SCR/SP11 genes were amplified by PCR and their sequences were determined. The results showed that: (i) out of the 18 DH broccoli lines, 15 belonged to Class II S-haplotypes, while the other three lines were Class I, based on the amplification patterns of SRK and SCR/SP11; (ii) the sequences of Class II S-haplotype SRK and SCR/SP11 fragments of 15 of the DH lines were identical; (iii) the Class I S-haplotypes of three DH lines were different from each other, based on the DNA sequences of their SRK genes; and (iv) one Class II and three Class I S-haplotypes were present in the broccoli DH lines