Preliminary Study Of Compatibility In Recessive Self-compatibility(SC) Accessions ‘230’ And ‘326’

Self-incompatibility systems have been exploited in many Brassica plant families to enforce outcrossing(by preventing self-fertilization),of course, which is also necessary for adaptation.The cultivated Brassica napus is self-compatible, while artificially synthesized Brassica napus is self-incompatible, indicating that cultivated Brassica napus have lost self-incompatibility in the evolutionary process. In the present study, many cultivated Brassica napus are more dominant than the line ‘S-1300’, which are known as dominant self-compatibility(SI) accessions, the others are called recessive self-compatibility(SC) accessions. SI line ‘S-1300’ and ‘230’, ‘326’ recessive self-compatibility(SC) accessions were used to identify genetic mechanism of recessive SC lines through the methods of clone and expression of S-locus gene, genetic investigation, genetic transformation. The key results were listed as follows:1. The function of SMI on the promoter of SCR(both are in II class) in ArabidopsisClone SMI gene on C genome in Brassica napus with homology based candidate gene methodology to transform Arabidopsis, at the same time, clone the promoter of SCR in Brassica napus and combine GUS CDS to transform Arabidopsis. The SMI gene(II class) in Brassica napus has no function on the promoter of SCR(II class) in Arabidopsis system.2. Gene expression of SCRBnSCR-6 and BnSCR-7 were expressed in ‘230’ anthers, while not in ‘326’, indicating that different regulations occur in SCR of ‘230’ and ‘326’. BnSCR-1300 transcripts were presented at high levels in anther of self-incompatible ‘S-1300’ and F1 hybrids, indicating that BnSCR-1300 expression is necessary for the SI.3. Genetic analysis of the compatibility in ‘230’ and ‘326’‘230’ and ‘326’ had the S genotype BnS-7 on the A genome, BnS-6 shared with the ‘S-1300’ on the C genome; the genetic analysis of the compatibility in ‘230’ and ‘326’ was in line with Mendel rule on the whole; while phenotypes of BnS-7BnS-7 and S-1300BnS-7 plants were segregated in ‘326’, suggesting that factor(s) outside of the S locus were involved in compatibility of ‘326’.4. T-DNA flanking sequence analysisT1 generation of transgenic plants presented the same amplification banding patterns. In fact, T-DNA just inserted in the second exon of GSBRNA2T0017974001, belonging to single stranded insertion, which maybe masked the function of transgene.