摘要：采用不同浓度聚乙二醇溶液（0、2。5%、5%、7。5%、15%、20%）模拟渗透胁迫，研究不同浓度渗透胁迫下四种禾本科种子的酶活性、发芽率、发芽势和发芽指数等指标的变化情况。结果表明：渗透胁迫不断加剧，以及渗透胁迫时间延长，高粱(Sorghum bicolor(L。) Moench)、玉米(Zea mays L。)、谷子(Setaria italica)种子各指标表现出明显的降低趋势，麦子种子(Triticum aestivuml)的各指标表现为先上升后下降。说明渗透势低对麦子的萌发具有抑制作用，渗透势高促进麦子种子萌发；谷子种子对水分的变化不敏感，表现为在各渗透胁迫时，谷子种子的各指标均无显著变化；高粱种子各指标则总体呈显著下降，表现出渗透势低对高粱种子萌发的抑制作用；玉米种子各指标先短暂升高后缓缓下降，表明一定渗透势胁迫可延缓其萌发；其中，谷子和高粱种子在前1-2d呈现爆发式萌发特征，而后萌发速度下降，玉米种子在20%PEG溶液处理下，可短暂改变其萌发特性；各种子酶活性与PEG浓度变化呈基本正相关，酶活性也可大致反应，随着渗透势胁迫，种子萌发的变化情况。77061

本研究将为致力于研究，植物种子（禾本科）发芽时所需的土壤水分的基本情况。

毕业论文关键词：禾本科：玉米；谷子；高粱；小麦；渗透胁迫

Effect of polyethylence glycol osmotic stress on seed germination of four Gramineae

Abstract:This experiment used PEG solutions with different concentrations of osmotic stress  --- 0,2。5%。 5%, 7。5%, 15%, 20% ----- to study its influence on the enzymatic activity of four gramineous seed, germination rate, germination potential and germination index。 The results showed that as the osmotic stress and the osmotic stress time increase, all indexes of sorghum, corn(Sorghum bicolor (L。) Moench),Maize seeds(Zea mays L。) and Millet seeds (osmotic stress)showed obvious decreasing trend, and the index of wheat seed(Triticum aestivuml) first increased and then decreased。 The results indicate that low osmotic pressure inhibited wheat germination, while high osmotic pressure promote germination of wheat seed。 Water doesn't seem to have significant influence over millet seeds, in that the indexes of millet seed had no significant change under different osmotic pressure。 Increased osmotic pressure seems to inhibit the germination of sorghum seeds in that the indexes of sorghum seeds in general significantly decreased。 Indexes of maize seed first showed transient increase and then slowly decreased, indicating that certain osmotic pressure can delay the germination。 Among all the seeds, sorghum and millet seeds presented explosive germination in the first 1-2 days and decreasing germination rate from then on。 Under the treatment of 20% PEG solution the germination characteristics of maize seeds can be temporarily changed。 In general, enzymatic activities of all seeds positively correlate with PEG concentration。 Osmotic potential threat can also activate enzymatic activity and change the rate of seed germination。This study will be dedicated to investigating plant seeds germinate (poaceae) under the basic situation of soil moisture。

Keywords：Gramineae：Setaria italica；Sorghum bicolor (L。) Moench；Zea mays L。；osmotic stress

目录

前言 1

1 材料与方法 1

1。1 试验材料 1

1。2 试验试剂 2

1。3　试验方法 2

1。3。1试验处理与方法 2

1。3。2淀粉酶活性测定 3

1。4 试验分组