Preliminary Study On The Molecular Mechanism Of Self-incompatibility In Brassica Napus L

Self-incompatibility is one of the most important ways for utilizing heterosis. However,there are few reports on molecular mechanism of self-incompatibility in Brassica napus L.Sef-incompatible Brassica napus line,S1300,and 124 self-compatible Brassica napus accessions are used to do the preliminary analysis of the molecular mechanism of self-compatiblility / self-incompatibility of Brassica napus by cloning SRK,SP11 and SLG(BnSRK-S-1300,BnSP11-S-1300 and BnSLG-S-1300) genes of S-1300,estabilishing the molecular marker system of SCAR to identify S genotype of brassica napus and analyzing differential expression of SRK and SP11 among S-1300,the male parents and F₁.The main results are as follows:1.Full length of nucleotide sequence of SRK,SP11 and SLG of S-1300 is acquired respectively.BnSRK-S-1300 has 8367 bp,containing 7 extrons and 6 introns; BnSP11-S-1300 has 607 bp,containing 2 extrons and 1 intron;BnSLG-S-1300 has 1672 bp,containing 2 extrons and 1 intron.2.BnSRK-S-1300 has the highest identity,98%,with BrSLG-60.Diversities between BnSRK-S-1300 and BrSLG-60 are mainly in Exon4,Intron4,Intron5 and Intron6. Compared with BrSRK-60,Exon4 of BnSRK-S-1300 has 91%identity,and Intron4,Intron5 and Intron6 of BnSRK-S-1300 are all below 82%identity.BnSP11-S-1300 is 100%identity with BrSP11-60,but between BnSP11-S-1300 and BoSP11-15 with 97% identity,having 5 bp insertion and 2 bp deletion.BnSLG-S-1300 has the highest identity, 99%,with BrSLG-60 and with BoSLGB,98%identity.All the results demonstrate that S-1300 owns a new S haplotype and might have the same ancestor with B.rapa S60.3.One set of SCAR molecular marker system has been developed,which includes two multi-PCR markers(ISLG+SP110,ISLGb+ SP11a) and one single-PCR marker (SRKa) for identifying S genotype of Bassica napus.4.Selecting Brassica napus of E genotype and F genotype as male parents by molecular markers,S-1300 as female parent as well as their F₁ for expression research. The results of Northern blot and Realtime PCR all show that SP11 only expressed in S-1300,and SRK expressed in all materials and highest in S-1300.