玉米种子萌发成苗不同阶段需水阈值的研究

用渗透势不同的聚乙二醇（ＰＥＧ）６０００模拟外界环境水分条件，对玉米不同品种的种子在萌动、萌发及成苗三个阶段需水的量化研究表明，种苗的抗旱性随吸水进程的推进而减弱；种子在萌动、萌发及胚芽伸长至一定长度的时间（ｔ）与外界环境水势（ｗ）之间存在着１／ｔ＝ａ＋ｂｗ的关系，据此推算出不同品种在不同成苗阶段的需水阈值，发现不同品种在同一成苗过程中对环境水分条件的反应不同，它们的抗旱性也不同。

STUDY OF WATER REQUIREMENT DURING SEED GERMINATION AND SEEDLING ESTABLISHMENT OF MAIZE SEEDS

Water requirements during stages of maize seeds radicle emergence, plumule emergence and seedling establishment have been studied with PEG imitating external water potentials. The experiments demonstrate that drought - resistance abilities of each cultivar drow with water tiptake proceeding; the relationships between radicle emergence time, plumule emergence time or seedling establishment time and external water potential seperately can be regressed with the formula 1/t=a+bw,and the critical water potentials derived from the formula exist difference within each cultivar.