PEG模拟干旱胁迫条件下玉米种子的萌发特性研究

为了探究在土壤干旱胁迫条件下玉米种子的萌发特性，通过室内不同浓度PEG溶液模拟不同程度的干旱胁迫，以4个玉米品种为材料，调查、分析各PEG浓度下玉米种子的发芽特性。结果表明，随着PEG浓度的升高，4个玉米品种种子的萌发及相关指标均有显著的延缓效应：种子发芽率(GR)、发芽势(GP)、平均发芽速(GV)随着PEG浓度的升高而呈明显下降趋势；D第一粒、D峰值所需天数随着干旱程度的加深向后推移1~3天；在各PEG浓度下，L胚根、L胚轴、L全株长度受到明显的抑制。籽粒形态不同的各品种间延缓效应差异显著，说明当土壤处于一定程度的干旱胁迫时，玉米小籽粒种子发芽更快，而大籽粒种子表现出更强的耐旱性。

Effects of Polyethyleneglycol (PEG) Simulated Drought Stress on Seed Germination Characters in Maize

In order to explore the germination character of maize seed under soil drought stress condition, we simulated different drought stress degrees by different polyethyleneglycol （PEG） solution. With four maize varieties as test material, we studied and analyzed seeds germination situation in PEG simulated drought stress. The results showed that corn seeds geminated indexes existed significant delayed effects with increasing PEG concentration. With the concentration enrichment, seeds germination percentage, germination potential and mean germination speed showed a downtrend, days in first seed germinated and days in seed germination peak delayed one day to three day. The length of seedlings radicle, hypocotyl and whole plant was restrained in different PEG concentration. The effect was remarkably different in four maize varieties with different grains. It explained that smaller grain corn seed had faster germinating ability in some degree of soil drought stress, whereas, the bigger grain corn seed showed stronger drought resistance.