Abstract: Effects of nitrogen fertilizer rates on expression and degradation of Bt-protein in leaves and bolls was studied using transgenic cotton under field condition． The nitrogen fertilizer rates were 450 kg /ha(high nitrogen), 225 kg /ha(medium nitrogen) and 0 kg /ha(CK), respectively． The results showed that nitrogen fertilizer rates had a significant regulation role on expression and degradation of Bt-protein and its yield in transgenic cotton． The content of Bt-protein in leaves of expanding stage， functioning stage and senescing stage indicated that medium nitrogen treatments >high nitrogen treatments >CK，and the residue of Bt-protein in leaves of shedding stage showed the same trend． Among which the content of Bt-protein in leaves of expanding stage， functioning stage， senescing stage and shedding stage，CK was 71． 22%， 79． 26%， 72． 49%， 59． 08% lower than medium nitrogen． The content of Btprotein in shell， fiber and seed of bolls showed high nitrogen treatments >medium nitrogen treatments >CK when the boll was expanding stage and filling stage，and the residue of Bt-protein in boll opening stage revealed the same trend as before． The content of free amino acids， soluble protein and total nitrogen in leaves increased with the nitrogen fertilizer rates． The lint yield applied medium nitrogen and high nitrogen were increased by 20． 50% and 19. 82% than CK， respectively． It was concluded that applying nitrogen 225 kg /ha was benefit to transgenic cotton when cotton yields and the expression and degradation of Bt-protein was concerned．

Key words: Nitrogen fertilizer rates, Transgenic cotton, Bt-protein, Nitrogen metabolism, Yield

CLC Number: 

• S143． 1