Abstract: Using the spring wheat variety Ningchun 4,the effects of selenium (Se) fertilizer as seed manure on Se absorption and distribution,and the influence of Se amount and fertilization method on the content of Se in grain were investigated in field experiments in Tumochuan plain.The results showed that the Se content in grain was increased from 0.103 to 0.218 mg/kg with increase in Se fertilizer rate from 75 to 300 kg/hm^2 (34.29-136.89 g Se/hm^2).The Se content in grain did not differ between the two fertilization methods.The Se content of the whole plant ranged from 0.093-0.514 mg/kg with application 150 g/hm^2 of Se fertilizer as seeding-fertilizer.The average seedling Se content was 0.219 mg/kg and could be improved by 2.6 times.The Se content in different organs of seedlings declined in the order leaf > seed > husks > stem.At the ripening stage,the order of Se content in different organs was stem > seed > husks > leaf.The quantity of uptake of Se by spring wheat in the whole plant changed as a s curve.it was fitted by the logistic equation to Se fertilizer treatment.The fastest absorption velocity was 0.017 μg/(d·plant) and was increased by 325% compared with the check treatment.The content of Se in leaves gradually decreased with spring wheat growth,however,the content in grain gradually increased.The Se harvest index when Se was applied as Se seed manure was 42.0% at the mature stage,which was increased by 0.43 % above the control.

Key words: Spring wheat;Selenium;Seed manure;Absorption and distribution