| Carotenoids are a class of pigments which widespread in nature. They are terpenoid compounds with number of conjugated double bonds. Carotenoids are closely related to human health and have much of biological functions, such as antioxidation, preventing cardiovascular disease and cancer, antiaging and etc. Cultivating the high carotenoid rapeseed not only plays an important role in absorption of vitamin A in human, but also in extending shelf-life and enhancing the quality of frying of rapeseed oil. Therefore, it is a new direction of development in the high carotenoid rapeseed of quality breeding in the future. This is a great significance for high quality breeding of carotenoid and molecular breeding that the research of composition and content of carotenoids in rapeseed, establishing a rapid and accurate analysis of carotenoids and defining the inheritance in the key gene of carotenoid synthesis.Ultrasound technology is used in this experiment to extracting the carotenoids from rapeseed. The experiment uses the HPLC method for a comparative analysis of the content and composition of the carotenoids of the three types of rape. Meanwhile, according to the genetic characteristics of a high degree of homology between rape and Arabidopsis thaliana which is the model plant, we speculate that the functional genes if might lead to the mutation of the content and composition of the carotenoids. Furthermore, we try identifying the functional genes which control the composition and content of the carotenoids by some Molecular biology techniques, namely Gene cloning, PCR amplification and Race RACE and so on. This provides a theoretical foundation and technical system for further deepening the study of rapeseed quality breeding. The main results of this experiment as follows:1. In order to extract the carotenoids of rapeseed fully, we use ultrasound technology to optimize the conditions of the extraction by designing the different single factors. The best conditions of the extraction is that 15℃of temperature ,the ratio of the extractants (acetone/petroleum ether) 1:1, material liquid than 1:12.5 (0.2g/2.5ml), ultrasonic frequency (kHZ)/power (W) 45/100, extracting 3 times. Compared with shaker extraction, utrasonic method could extract the carotenoids of rapeseed more rapidly, accurately and stably. And we can choose the varieties of rapeseed which are different content of carotenoids so as to lay a good foundation that screening a large number of outstanding high genetic resources of carotenoid.2. We use high performance liquid chromatography (HPLC) to determinate the contents of 60 copies of three different types of rape. The finding as follows: the carotenoid composition is very similar among the three types of rapeseed. It mainly contains lutein andβ-carotene, and lutein-based. But among the three species, the ratio of two pigments in content is different. This provides a theory for genetic manipulation in carotenoid-quality breeding in the future.At the same time, ultrasonic method extracting the total carotenoids from rapeseed is tested by HPLC method. Through using the statistical software the name is SPSS, we get the following results that at a significant level of 0.01, P value is 0.950**. We see P value is far greater than the significant level ofα, in other words, the correlation between two methods reached a very significant level. This is further evidence that the stability of ultrasonic extraction of carotenoids in rapeseed is higher than before.3. According to the genetic characteristics of a high degree of homology between Braassica rapa L. and Arabidopsis thaliana, we can get cDNA and DNA genetic information of two genes (PSY and PDS3) of Arabidopsis thaliana .And we design primers of those two genes of Braassica rapa L. by the methods of electronic splicing which is mentioned in bioinformatics. The sequences of cDNA and DNA of two genes which are the key enzyme gene have successfully been cloned from Braassica rapa L.. The length of the cDNA of those two genes is 1515bp and 1940bp. The DNA length is 2690bp and 3911bp. This provides a theoretical basis that we can further explore the molecular mechanisms of the mutation of carotenoid composition and content of rapeseed. At the same time, it provides a theoretical basis for molecular breeding of high caroteniod in rape.
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