水分处理对榆树幼苗不同器官非结构性碳水化合物的影响

设置正常供水、轻度、中度和重度干旱处理,分析两年生榆树幼苗不同器官的可溶性糖、淀粉及非结构性碳水化合物(NSC)随处理时间延长(15、30、45 d和60 d)的变化特征。结果表明:水分处理15 d时,随着干旱程度增加,叶片和细根可溶性糖含量呈下降趋势,叶片淀粉含量在中度和重度干旱处理最低,为(18.35±0.06)mg·g^-1,茎和粗根可溶性糖含量在重度干旱处理显著低于其他处理。处理30 d时,叶片淀粉和NSC含量随干旱程度增加呈上升趋势,且叶片淀粉含量在重度干旱处理最高,为(47.83±0.27)mg·g^-1,茎和粗根淀粉及NSC含量在轻度干旱处理下显著低于适宜水分处理。处理45 d时,随干旱程度增加,细根可溶性糖/淀粉呈下降趋势,叶片可溶性糖含量、可溶性糖/淀粉和茎淀粉含量在重度干旱处理显著高于其他处理。处理60 d时,随着干旱程度增加,叶片和细根可溶性糖/淀粉逐渐增加,粗根可溶性糖、淀粉和NSC含量在重度干旱处理显著高于其他处理,并且NSC含量达到最大值(68.88±1.01)mg·g^-1。以上结果表明,榆树幼苗各器官可溶性糖、淀粉及NSC含量随着处理时间延长做出不同的响应,各器官NSC下降,并在粗根中积累。这为科尔沁沙地榆树防护林的水分管理提供依据。

Effects of Different Water Treatments on Non-Structural Carbohydrates in Different Organs of Ulmus pumila Seedlings in the Horqin Sandy Land

Two-year-old Ulmus pumila seedlings were grown under suitable water,mild,moderate and severe drought treatments.The soluble sugar,starch and non-structural carbohydrate(NSC)contents in different organs of the seedlings were measured after the drought treatment for 15,30,45 and 60 days.The results showed that,on the 15 th day of treatment,the soluble sugar contents in leaves and fine roots decreased with the increase of drought level,and the starch content in leaves under moderate and severe drought treatments reduced to the minimum value(18.35±0.06)mg·g^-1.The soluble sugar contents in stems and coarse roots under severe drought treatment were significantly lower than those under other treatments.On the 30 th day of treatment,the starch and NSC contents in leaves increased with the increase of drought degree,and the starch content in leaves under severe drought treatment increased to the maximum value(47.83±0.27)mg·g^-1.The starch and NSC contents in stems and coarse roots under mild drought treatment were lower than those under suitable water treatment.On the 45 th day of treatment,the ratio of soluble sugar and starch in fine roots decreased with the increase of drought level.The soluble sugar content,ratio of soluble sugar and starch in leaves and the starch in stems under severe drought treatment were significantly higher than those under other treatments.On the 60 th day of treatment,the ratio of soluble sugar and starch in leaves and fine roots gradually increased with the increase of drought degree.The soluble sugar,starch and NSC contents in coarse roots under severe drought treatment were significantly higher than those under other treatments,and the content of NSC increased to the maximum value(68.88±1.01)mg·g^-1.The above results indicated that soluble sugar,starch and NSC in all organs of U.pumila seedlings differently responded with the increase of treatment time.The NSC in each organ decreased and accumulated in coarse roots.This provides an evidence for water management of U.pumila protection forest in Horqin sandy land.