Breeding For Recessive Genic Male Sterile Lines With High Oleic Acid Through Marker-assisted Selection In Brassica Napus

Rapeseed is the third major source of plant oil in the world, as well as the main source of domestic plant oil in our country. Improving the content of different fatty acid in the rapeseed oil can increase its edible value and competitiveness as a kind of new energy source or industrial resource. Increasing the proportion of the oleic acid in the fatty acid is one of the most important goal for improvement of the fatty acid in rapeseed. The purposes of this research are to breed the recessive genic male sterile lines with high oleic acid through marker-assisted selection, which can provide breeding materials for the production of hybrid seed with high oleic acid, and develop efficient methods for marker-assisted selection. The main results are as follows:1. Sterile(AAms1ms1), maintainer(AAMs1ms1) and restorer(AAMs1Ms1) plants with high oleic acid have been selected from the BC2F2 population of three backcrossing combinations(Jia ZL593A×Jia9800, Jia ZL353A×11pin6, Jia ZL100A× Jia9829), and heterozygous individuals(Aa Ms1ms1) have also been selected from the BC3F1 population of the same backcrossing combinations. Meanwhile, the individuals which are heterozygous(Aa Ms1ms1) have been selected from the BC1F1 population of two backcrossing combinations(Jia ZL360A×11pin9, Jia ZL353A×Jia9829).2. Based on previous studies, specific primers for sterile allele ms1 have been designed again, which have subsequently been tested in double PCR. Primer pais of Ms1-2F-1 and Ms1-2R-6 together with the primers for Ms1 in double PCR performed the best, which can distinguish recessive homozygous, dominant homozygous and heterozygous genotype in one reaction. The tested primers were used to identify the fertility genotype of the individuals in the BC2F2 population. The accuracy of these primers in foreground selection has been verified by the consistency of the results between genotype identification and phenotypy survey.3. All the five recurrent parents have been confirmed to have the homozygous genotype ms2ms2 by detecting the five population from backcrossing combinations(Jia ZL593A×Jia9800, Jia ZL353A×11pin6, Jia ZL100A× Jia9829, Jia ZL360A×11pin9,Jia ZL353A×Jia9829) and five recurrent parents(Jia9800, 11pin6, Jia9829, 11pin9,Jia9829) using the markers of Ms2 and ms2. The detection among 96 normal fertile rapeseed materials with markers of Ms2 and Ms1 has showed that there were 35 materials with ms2, of which 21 materials were homozygous and 14 materials were heterozygous;there were 92 materials with normal fertile genotype Ms1Ms1 and 4 materials with heterozygous fertile genotype Ms1ms1.4. The selected individuals by foreground selection in the BC1F1 population from three backcrossing combinations(Jia ZL593A×Jia9800, Jia ZL353A×11pin6, Jia ZL100A×Jia9829) have subsequently been screened by AFLP markers in background selection. Six individuals containing the highest recovering ratio of recurrent parent genome were selected from each backcrossing combinations with the highest recovering ratio as high as90.3%.5. The selected individuals by foreground selection in BC3F1 and BC2F2 population from three backcrossing combinations(Jia ZL593A×Jia9800, Jia ZL353A×11pin6,Jia ZL100A× Jia9829) have subsequently been screened by markers flanking target genes Bn FAD2 and Ms1 to obtain individuals with recombination and exchange. Five individuals with single exchange close to Bn FAD2 were selected from backcrossing combination Jia ZL593A×Jia9800, as well as one individual with double exchange close to Bn FAD2 and three individuals with single exchange close to Ms1. There were two individuals(DL056-1 and DL061-6) with single exchanges close to both Bn FAD2 and Ms1. In the backcrossing combination Jia ZL353A×11pin6, there were13 individuals with single exchange close to Bn FAD2 and 3 individuals with single exchange close to Ms1; In backcrossing combination Jia ZL100A× Jia9829, there were 2 individuals with single exchange close to Bn FAD2, 2 individuals with double exchange close to Bn FAD2, 1individual with single exchange close to Ms1, 1 individual(DL118-8) with double exchange close to Bn FAD2 and single exchange close to Ms1.