The Accumulation Regulation Of Selenium And Primary Separation Of Selenium-content In Brassica Napus

Selenium is one of important elements to life, above 60 kinds of diseases and cancers are related to the lack of selenium. Selenium is distributed widely but extremely unevenly on the earth, 2/3 of area in the world lacks selenium and so does China, of which 1/3 is considered to be in terrible lack of selenium. This situation seriously threatens the health of human beings and the development of animal husbandry. The nutritive level of selenium in human and pultry is determinated by the selenium content in the food taken. Plant is the key link in the ecological selenium and the inorganic selenium cycle and it is also the most important direct selenium resource for the human and the poultry.Using multi- physiological and biochemical methods, the author studied systematically the selenium application on Brassica Napus from all aspects. Combining soil culture and liquid culture and using atom absorption spectrometry to detect selenium, the author studied systematically the following items on Brassica Napus: the trends of the absorption, accumulation, distribution of selenium in seedling stage, the endurance ability with the selenium in the environment,the effect of different provided selenium level in the growth and development, dry matter, accumulation of selenium,the producing and the content of selenium in Brassica Napus. According to the analysis on the protein, the amino acid content and the measurement of the activity of NR, peroxidese, SOD, Amylase etc and MDA which is the product of Lipid per oxidation and using unprovided selenium and different provided selenium, the author studied the physiological function and interior mechanism of selenium in organic body and its resistance. In addition, the author managed to extract and separate the protein containing selenium by the fractional precipitation, and probed the occurrence form of selenium in Brassica Napus.The Brassica Napus could accumulate and absorb selenium in the environment positively even with high selenium concentration and thus made the selenium concentration higher than that of the environment. The accumulation become stronger and stronger with the development. The selenium absorbed by the root system was transferred to different organ and accumulated there.The selenium content in different organs increased with the maturing of the organ, and in harvest time of seeding stage, selenium content of each organ is: root >leaf >stem. Most part of the selenium absorbed by the plant was converted intoorganic selenium by anabolism, and the content in soluble biological macromolecules is: protein >polysaccharide >nucleic acid. The selenium content in different types of protein is: salt-soluble protein >water-soluble protein >gliadin >alkali-soluble protein. In the leaf blade, the protein-selenium is little, but it is also the main mode of binding. Brassica Napus endurance ability with the selenium in the environment was related to the method which selenium was provided and increase with the mature and the ability of soil to keep the selenium within proper selenium concentration. The biological effect of selenium on the Brassica Napus conforms to the general dose rule of microelement. Within the low concentration (21.0mgSe.kg-1 soil in soil culture, 15.0 mgSe.kg-1 soil in liquid culture),with the selenium concentration increaseing;there will be the following changes: the deoxidation ability of root system increases and so does the content of chloroplast and protein; per oxidation product MDA decreases. Under the same situation, selenium has many functions as obviously promoting the growth and development, keeping high vigor, slowing ghee senescence, improving the quality. However, high concentration selenium can change the indexes above mentioned conversely and even take the toxic effect on the Brassica Napus growth. Fractionally precipitation was chosen from many separation methods developed to extract the protein containing selenium in Brassica Napus. This method provided the basis to the further purification of the protein containing selenium.Accordi...