Abstract: This paper studied effect of different stalk cutting time on upper leaves amino acid content before and after the air-curing of burley tobacco TN 86. The results showed that,the total acids content was in the range of 124. 47- 140. 78 mg / g,the content and ratio of Tyr were higher before the air-curing,the Asp acid content was in the range of 7. 78- 11. 16 mg / g at different stalk cutting time before the air-curing,manifested as topping four weeks six weeks five weeks three weeks two weeks. There was a significant level between Gly,Thr and stalk cutting time before the air-curing. The total acids content was in the range of 73. 78- 97. 77 mg / g,the content and proportion of Asp were higher after the air-curing. The Asp acid content was in the range of 23. 73- 31. 25 mg / g at different stalks cutting time after the air-curing; its content received a higher proportion when stalk cutting after topping two weeks and its ratio received a higher proportion when stalk cutting after topping four weeks. The content and the ratio of Asp were not high before the air-curing,but increased significantly after the air-curing. There was a extremely significant level between Gly,Thr,Pro,Ile,Leu,Lys,Phe,Tyr and stalk cutting time; there was a significant level between Asp,His,Arg,Ala,Val,Met,total amino acids and stalk cutting time. Effect of the amino acid contents after air-curing was greater than before air-curing at different stalk cutting time. It was conducive to the accumulation and formation of Asp acid in upper leaves when stalk cutting after topping two weeks.

Key words: Burley tobacco, Upper leaves, Stalk cutting time, Amino acid, Air-curing

CLC Number: 

• S572