Selecting The Molecular Markers Of High Oleic Acid In Brassica Napus

Rapeseed is one of the important oil crops in China, and its development trends is to cultivate and promote the "Triple low"(low sulfur glycosides, low erucic acid and low fibre)、"Triple high"(high oil content, high oleic acid and high protein) varieties. By using of molecular marker technology, breeders can breed the specific fatty acid content of variety rapidly. In this study, we used F2population which were crossed by low oleic acid and high linolenic acid10L421and high oleic acid and low linolenic acid10L422to screen the molecular markers related to the high oleic acid content of Brassica napus. Therefore, our study followed the two aspects of research:1. Using gas chromatograph to measure the seed oleic acid content of Brassica napus10L421,10L422and their hybrid combination F2population. The results were as follows:The oleic acid content of F2population showed continuous distribution and a large variation, a nearly single peak and normal distribution were showed too. The variation of oleic acid content arranged from39.05%to86.42%, and the amplitude was about47percent. The contents were more concentrated between52%and77%with an average content of62.22%. The chi-square test x2=0.183<x20.051=3.84, low oleic and high oleic acid content were in lined with the separation ratio of15:1which meant in Brassica napus the high oleic acid content was determined by two pairs of recessive genes.2. Brassica napus is an allotetraploid (B.napus), it’s formed by natural hybridization and chromosome doubling from Brassica rapa (B.rapa, A genome) and Brassica oleracea (B.oleracea, C genome). The genome constitute of Brassica napus is AACC. Researches have shown that FAD2gene is an important gene to control the content of oleic acid, and located in linkage group A01, A05, C01and C05.The major QTLs of oleic acid content are located in linkage group A05, the micro-effect QTLs are located in linkage group A01. Therefore, this study focused on these four linkage groups, designed SSR primers near by FAD2genes, found the related molecular markers which controlled the oleic acid content. We found that oleic acid content related to the SSR markers in A01, A05, C01and C05linkage group more or less. SSR markers in A05and A01linkage group accounted for18.6%and9.5%of the oleic acid phenotype variation with single marker regression analysis, respectively. Therefore we thought that the FAD2gene recessive mutation in A05and A01accounted for the major part of the oleic acid content variation in our F2population. These markers could be used as molecular markers for selecting high oleic acid content of Brassica napus.