冷蒿非结构性碳水化合物代谢对机械损伤的响应

为了探讨放牧过程牲畜采食和践踏损伤对冷蒿Artemisia frigida体内非结构性碳水化合物代谢的影响,对盆栽冷蒿枝叶采用不同程度(轻度、中度、重度)机械损伤的方式模拟放牧,测定了冷蒿叶片和根部蔗糖、葡萄糖、果糖和淀粉质量分数的变化。结果表明:在损伤初期,轻度和中度处理后冷蒿叶片中蔗糖、葡萄糖和淀粉质量分数显著增加(P<0.05);到损伤24 h,3种处理中蔗糖质量分数基本恢复到对照水平,而葡萄糖和淀粉质量分数显著下降,与对照相比,葡萄糖质量分数降了60.0%,74.6%和80.1%,淀粉质量分数下降了43.4%,45.2%和77.2%。葡萄糖和果糖结合成蔗糖,使其质量分数较高,在冷蒿体内积累。冷蒿根部非结构性碳水化合物质量分数变化与叶片相比是有所不同的。损伤初期,冷蒿根部葡萄糖质量分数上升,3种处理与对照相比分别增加了62.9%,94.3%和34.3%,果糖在轻度机械损伤处理后明显上升;到损伤后期,葡萄糖和果糖恢复到对照水平,蔗糖和淀粉随着损伤加强而下降。根部积累的主要是蔗糖和淀粉。冷蒿受损伤后,体内淀粉、蔗糖、葡萄糖质量分数发生变化,参加应急反应,同时轻度损伤可以增加冷蒿体内非结构性碳水化合物。

Responses of non-structural carbohydrate metabolism to mechanical damage in Artemisia frigida

To determine the effect of grazing and trampling damage of livestock on the metabolism of non-structural carbohydrates in Artemisia frigida, mechanical damage at different degrees (light, moderate, and severe) was applied to simulate grazing. The content of starch, fructose, glucose, and sucrose in leaves and roots were determined. Results showed that in the early stage with light and moderate mechanical damage, sucrose, glucose, and starch content of A. frigida leaves increased significantly (P<0.05). Sucrose content under all the three treatments restored to the level of the control in 24 h; whereas glucose decreased by 60.0%, 74.6%, and 80.1%(P<0.05), respectively, under light, moderate, and high treatments, whereas starch content decreased by 43.4%, 45.2%, and 77.2% (P<0.05), respectively, under light, moderate, and heavy treatments. The variation pattern of non-structural carbohydrates in roots differed that in leaves. At early stage glucose content increased, by 62.9%, 94.3%, and 34.3% (P<0.05), respectively, under light, moderate, and heavy treatments. Fructose content increased significantly at early stage of light treatment. At late stages of three treatments, glucose and fructose contents were restored to the control level; however, sucrose and starch contents decreased with increasing damage. Sucrose and starch were accumulated mainly in roots. Thus, after treatments, the content of starch, sucrose, and glucose in A. frigida changed in response to emergency while mild damage increased the content of non-structural carbohydrates.