Abstract
The incompatibility reaction in Brassica depends on the interaction between SP11 (pollen) and SRK (stigma), both of which are encoded in the S locus. Brassica oleracea and Brassica rapa are generally self-incompatible, but there are a few self-compatible strains. In our study, the cause of the self-compatibility was investigated using self-compatible strains in B. oleracea and B. rapa. There is a self-incompatible strain which has the same S haplotype as the self-compatible strain in B. oleracea. Pollination test and RT-PCR analysis indicated that SP11 and SRK are not functional and not transcribed. In the self-compatible strain in B. rapa, a large S locus region was cloned and gene structures of SP11 and SRK were analyzed. RT-PCR analysis revealed that SP11 and SRK were not transcribed. The self-compatibility of these lines was found to be resulted from disruptions of both SP11 and SRK.
