Identification Of A New High Oleic Acid Locus In Brassica Napus

Rapeseed is one of the most widely distributed crops in the world, and has a long history of cultivation among the major oil crops. The fatty acid composition of oilseed is an important index for evaluating the quality of it. The main target of rapeseed breeding in the worldwide is to improve the oleic acid content on the basis of low erucic acid breeding. At present, high oleic rapeseed resources are limited and the agronomic traits of them are poor which have a direct impact on the progress of high oleic acid rapeseed breeding in China. To identify novel resources controlling high oleic trait, we constructed doubled haploid (DH) lines from the microspore culture of F1whose parents are known high oleic material D126and a new rape resource H100, and linkage maps were constructed for mapping QTLs of fatty acid content traits. The main results are as follows:(1) The mapping population used in this study consists of163of DH lines sampled from550lines. A total length of2243.4cM of genetic linkage map is constructed with462SSR and InDel markers; the average distance of19linkage groups is4.86cM.(2) The content of various fatty acids in of the DH population exhibited a gaussian distribution and the two-way transgressive separation. The variations of oleic acid, linoleic acid and linolenic acid in the DH population are consistent in two years, and their heritability are91%,98%and88%, respectively, suggesting the genetic stability of the three traits is high. Correlation analysis of DH population of in two years showed that oleic acid had significantly negative correlation with linoleic acid, linolenic acid and oil content; correlation between linoleic acid, linolenic acid and oil is uncertain in two years; linolenic acid had significant positive correlation with oil content.(3) With the data of rape quality traits collected from in2011and2012,6of31QTLs are detected in the two years in the DH population. For palmitic acid,4QTLs are detected for only one year;3stearic acid QTLs are found for only one year;2of2oleic QTLs is discovered in the two years, and the one major effect QTLs are located on A5;1of6linoleic QTLs are detected twice;2of5linolenic QTLs are detected in both years, and the two major effect QTLs are located on A4and C4； Five QTLs for oIL content are detected respectively.(4) The main-effect QTL of DH population is located in the region of ZDM22-ZDM23on A5, which explain75.9%of variation, and a detected QTL is located on A9chromosome. A9alleles from H100can increase3%-5%of oleic acid content, representing a newly discovered QTL.