中文摘要：

为了研究不同质量分数（5%、15%、25%）聚乙二醇（PEG）预处理对2种海拔下春小麦种子的萌发、幼苗生长和抗旱性的影响。以2种海拔（1523 m、795 m）的‘新春11号’品种为材料,按照千粒重的不同将种子划分为大、中、小粒。结果表明：随着PEG质量分数的增加,2种海拔下的大、中、小粒种子的活力指数、叶面积和根系长度均显著减小,发芽率也逐渐减小,但不显著;种子根长在5%的处理下高于对照。高海拔下,不同大小种子在5%与15%处理下其根系长度比对照显著增加,低海拔在5%与15%时也比对照长,但在15%时与对照无显著性差异;低海拔下25%的种子根长比对照显著减小。2种海拔下不同PEG处理下的种子,其活力指数与叶面积均表现为大粒〉中粒〉小粒,且各粒级间有显著性差异;根系长度表现为小粒〉中粒〉大粒。同一浓度同一粒级间,高海拔下的各指标都显著高于低海拔下的。说明不同质量分数的PEG胁迫抑制‘新春11号’种子的萌发,低质量分数的胁迫促进根系的生长。大粒种子抵抗干旱胁迫的能力强于其他粒级种子。高海拔种子具有较高的抗旱性。

英文摘要：

The aim was to explore the effects of polyethylene glycol （PEG） pretreatment with different concentrations （5%, 15%, 25%） on the germination, seedling growth and drought resistance of spring wheat seeds at two altitudes. ＇Xinchun 11＇ planted at two kinds of elevation （1523 m, 795 m） were taken as materials, the seeds were divided into large, medium and small seeds in accordance with the 1000 grain weight. The results were as the following： vigor index, leaf area and root length of seeds with different sizes at the two altitudes reduced significantly along with the PEG mass fraction, and the germination rate also decreased, but not significantly. The root length of the seeds under the treatment of 5% was higher than that of the control. At high altitude, the root length of different sized seeds under treatment of 5% and 15% significantly increased compared with that of the control, the roots under treatment of 5% and 15% were also longer than that of the control at low altitude, but there was no significant difference between 15% treatment and control. Root length significantly decreased in the treatment of 25% at low altitude. Vigor index and leaf area showed large grain〉medium grain〉 small grain in different PEG treats at the two altitudes, and there were significant differences among different sized seeds. The root length was small grain 〉medium grain〉large grain. The indexes at high altitude were significantly higher than those at low altitude under the same concentration resistance.