Effects of water stress on physiological indicators in tree roots of five varieties | 水分胁迫对5个树种苗木根系部分生理指标的影响

Chinese. 明确不同树种苗木对水分胁迫适应的差异性，探讨不同树种的抗旱性机理。以1年生侧柏、刺槐、山杏、沙棘、柠条为试验树种，在盆栽条件下，比较不同水分胁迫处理（分别为田间持水量的75%，50%和35%）对5种苗木根系可溶性蛋白、可溶性糖和游离氨基酸代谢的影响。5个树种根系可溶性蛋白含量的变化规律因树种不同而有很大差异，随水分胁迫的加剧，山杏、侧柏根系中可溶性蛋白含量呈持续增加趋势，且山杏可溶性蛋白含量最多；在重度干旱胁迫下，刺槐、柠条根系中可溶性蛋白含量急剧增加，且增幅为刺槐＞柠条；而沙棘根系可溶性蛋白含量表现为，随着水分胁迫程度的增加呈先升后降的趋势，且在重度干旱处理下降至最低。随着水分胁迫强度的增加，5种苗木根系可溶性糖和游离氨基酸含量的变化趋势基本一致，均随着水分胁迫强度的增加而持续增高，其中在重度干旱胁迫时，山杏根系可溶性糖含量、游离氨基酸含量分别为20.54 mg/g，1.665 μg/g，远高于其他4个树种；随着水分胁迫强度的加剧，其余4个树种侧柏、沙棘、刺槐和柠条的可溶性糖和游离氨基酸含量与对照相比，增幅分别为171.43%，141.13%，131.42%，24.42%和313%，280%，317%，289%。5个树种在水分胁迫条件下，在诱导自身体内某些溶质的合成和累积，以及干旱胁迫诱导一些特定蛋白质的合成能力上都有较大差异。综合考虑各因素认为，5个树种在合成、累积这3类溶质方面的能力由强到弱依次为山杏＞侧柏＞刺槐＞柠条＞沙棘。

English. In order to ascertain the difference of the different seedlings’ adaptation to water stress, studies on drought resistance of different trees were conducted. The annual Platycladus orientalis, Robinia pseudoacacia, Armeniaca sibiria, Hippophae rhamnoides and Caragana korshinkii were used as the test trees, through artificial control of water amount, different water stress（Field water holding capacity of 75%, 50% and 35%）to soluble protein, soluble sugar content and free amino acid changes in these five sapling roots and drought resistance mechanism in different saplings were discussed. The change of soluble protein content of the five tree species showed significant difference to different species. With the increased drought stress, the soluble protein content also increased in P. orientalis and A. sibiria, and the soluble protein content in A. sibiria was the most. In the severe drought stress, the soluble protein content in C. korshinkii and R. pseudoacacia roots increased rapidly, and the increase range of the soluble protein content was R. pseudoacaciaC. korshinkii; By mild water stress in H. rhamnoides, the soluble protein content of its roots had a certain rate of increase, but with the increasing degree of drought, the soluble protein content rapidly dropped to the lowest. With the increase of water stress intensity, the changes in trends of soluble sugar and free amino acids in these five sapling roots sustained increasing with the increase of water stress strength, and the content of A. sibiria was far higher than that of the other four saplings, and with the increase of water stress intensity, the increase range of soluble sugar and free amino acids content of the rest four tree was P. orientalis R. pseudoacaciaC. korshinkiiH. rhamnoides. Under the condition of water stress, big differences exist in the five tree species induction of the synthesis and accumulation of some solute and the capacity of synthesis of some induced soluble protein, leading to different drought resistance. Finally the capacity of synthesizing and accumulating these three solutes in the five tree species is A. sibiriaP. orientalisR. pseudoacaciaC. korshinkiiH. rhamnoides._