用75Se对土壤-小麦系统中硒转移规律研究

STUDY ON Se TRANSLOCATION IN SOIL-WHEAT SYSTEM USING 75Se

Dark Brown Forest Soil was collected from Hengren in Liaoning. Aquesous solution of 75SeO2 is mixed with the soil. Se adsorption, distribution and accumulation in wheat v as studied with pot-experiments. Amount of 75Se uptaked by wheat depends on the stages of growth. It is more in seeding stage, lesser during jointing to heading,and has a rapid increase during heading to maturity.Se contents in wheat grain croped on the soil containing 0.131 ppm and 1.631 Ppm of Se are 0.023 ppm and 0.493 ppm, respectively. The order of 75Se distribution in different pans of wheat in terms of magnitude of Se is. Grain>Leaf>Root>Chaff>Leaf Sheath> Stem. For 75Se in leaf, the younger the leaf of wheat is, the more 75Se distributed. After wheat absorbed 75Se from soil, it is difficult to translocate 75Se to the aerial parts of wheat. Therefor, 75Se is accumulated mainly in root. After the seeds were planted, 75Se uptaken by root wore translocated upwards rapidly and were accumulated in stem and leaf. 75Se accumulation in loot appeared evidently along with growth of wheat, but after 15 days an equilibrium was established between the incoming and outgoing Se ions. Such a 75Se content in root was kept almost constant until maturity of wheat. Mathematical model for describing transportation of soil-Se to wheat has beee developed. These results are useful for increasing the Se intake to human living in disease area and for finding pathoginic factor of keshan disease and kaschin-Bek disease.