추파유채 ( Brassica napus L. ) 생육시기에 따른 비구조성 탄수화물 함량의 변화 ( Changes in the Non-Structural Carbohybrate Content during Growth Period in Forage Raps ( Brassica napus L. ) )

The objective of this study is to obtain the basic data for investigating the potentiality of continuous utilization (first cutting in the late fall and regrowth yield in next spring) of forage rape seeded in fall. Non-structural carbohydrates(NSC) in leaves and roots of forage rape seeded on Oct. 3 were analyzed during a growth period. The greatest change in NSC content was observed between the wintering and the early spring period. The total content of soluble sugar in leaves and roots highly increased from the late fall(Nov. 7) to the wintering period (Feb. 4), and then rapidly decreased on the early regrow^ period(Mar. 31). The contents of fructose and glucose were relatively lower, and their quantitative change also was smaller than those of other sugars through entire growth period. The highest accumulation of sucrose occured hum the late fall to wintering period, and then greatly decreased in the early regrowth period. Sucrose content in roots was 2.3 times higher than that of leaves in wintering period. Starch was the largest pool of NSC and its content in leaves and roots showed a similar pattern with that of sucrose through entire growth period. Starch contents in leaves and roots were 38mg and 189mgl gDM in the late fall(Nov. 7), 187 and 497mg/gDM(Feb. 4) in the wintering period and 69 and 79mglgDM(Mar. 28) in the early regrowth period, respectively. The results clearly showed that the main reserve forms of NSC are starch and sucrose, and that they are hlghly stored in roots in overwintering forage rape.