Correlation Analysis And QTL Mapping For Oil Content In Brassica Napus L.

Rape is a kind of brassica oil crops, The largest planting area of rape in China is b.napus rape, and is also head of China’s four major oil crops. It is the best vegetable oil because of its low content of saturated fatty acids, and is also China’s major source of edible vegetable oil. It can also be used for processing industrial oil and relieve the problem of energy shortage. The main affecting factor of rapeseed oil production is rapeseed yield and oil content. At present, the development of Chinese rapeseed yield has encountered the bottleneck, thus improving the seed oil content is particularly important. This study combines genetic mapping with correlation analysis for analysing the associated sites and QTL location of oil content. The main results were as follows:1 The analysis results of the phenotype data of oil content about 146 b.napus L. were as follows: the variation range of the percentage oil content was 19.3% ~ 45.20%, the average was 35.60%, coefficient of variation was 20.15%, this results shows that the trait differences between the varieties were large. The results of the normal distribution for the oil content data of 146 natural population were as follows: the trait was in normal distribution and variation continuity, it showed the characteristics of quantitative trait. So,it suitable for correlation analysis.2 The results of the amplification for 44 pairs of SRAP primers were as follows: first, 316 loci was detected with 316 polymorphic loci, and the percentage of polymorphism was 52.5 %. Second, the range of polymorphic loci per primer was 2~8, and the average number of polymorphic loci was 3.8. Third, the range of PIC was 0.374-0.856, and the average was 0.699. Thus, the genetic difference between the materials and genetic diversity is large. It was beneficial to find out the association of quantitative traits in the association analysis.3 The natural population of 146 material is analyzed by the software of STRUCTURE, which was divided into three subsets, Q1 and Q2 and Q3. Among them, Q1 subgroup mainly come from China, Q2 subgroup mainly come from Canada and Europe, Q3 subgroup mainly from mainly come from Australia.The community population structure is relatively simple and clear, so it fit for association analysis.4 Correlation analysis for Oil content in 146 natural population: in the model of Q, six significant correlation were detected(P<0.05) by 44 pairs of primers, the variation value of the interpretation phenotypic was between 0.112~0.355. Two loci of EM3ME5 and EM17ME24 were extremely significant(P<0.01).5 The analysis results of the phenotype data of oil content about parents and F2 population were as follows: the average oil content of F2 population was 38.12%, between 23.81%~48.47%, coefficient of variation was 22.35%, These showed that the separation of the offspring population was larger. At the same time, the trait was in normal distribution and variation continuity, it showed the characteristics of quantitative trait, so the group was suitable for drawing.6 Springfield-B(emasculation) as female parent and ymnm-8 as male parent to build 132 F2 population, and use the F2 population to draw genetic linkage map. Using SRAP molecular markers to build a genetic linkage map of brassica napus L..It concluded 15 linkage groups and 44 marker loci, the map length is 1039.6 cm, the average distance between markers is 23.63 cm. Analysis of QTL loci associated with oil content, and find out 2 QTL loci associated with oil content. Including qOC1 in group ofLG1 EM9ME6-EM17ME24 tag interval, mark of phenotypic can explain the variation value was 11.23%,additive effect is 0.48, q OC15 in group of LG1 EM3ME5-EM4ME22 a tag interval, mark of phenotypic can explain the variation value was 4.12%, the additive effect was 0.63.