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以抗旱性弱的青稞品种‘大麻青稞’为材料,研究不同质量分数(5%~30%)聚乙二醇(PEG)预处理对其种子萌发、幼苗生长和抗旱性的影响。结果表明,1)随着PEG预处理质量分数的增加,‘大麻青稞’种子的发芽率和生根率,幼苗的根长、苗高和鲜重均呈先增加后降低的趋势;种子的发芽率、生根率、幼苗的根长和苗高均在10%的PEG处理下值最高,分别为对照的1.14、1.05、1.24和1.33倍,且除生根率外,其他指标均与对照差异极显著(P<0.01);叶片可溶性蛋白和叶绿素先增加后降低,而丙二醛含量和相对电导率则先降低后增加,并在15%PEG处理下最佳,分别为对照的1.38、1.84、0.65和0.71倍,且与对照差异极显著(P<0.01);2)当幼苗经30%PEG重度胁迫时,其叶片蛋白质和叶绿素含量分别比胁迫前下降42.11%和38.98%,而经15%PEG预处理的两者含量比胁迫对照组提高了42.80%和1.01倍;经30%PEG重度胁迫后相对电导率和丙二醛含量分别比胁迫前上升了28.24%和6.04%,而经15%PEG预处理的两者含量比胁迫对照组降低了28.64%和33.41%。表明低质量分数的PEG对青稞种子的萌发和幼苗的生长生理特性具有促进作用,高质量分数的PEG处理对植物的生长产生了抑制作用。
The effect of PEG pretreatment on the seed germination, seedling growth and drought resistance of different species (5% -30%) of barley cultivars with low drought resistance was studied. The results showed that: 1) With the increase of PEG pretreatment, the seed germination rate and rooting rate, seedling root length, seedling height and fresh weight increased firstly and then decreased; the seed germination rate , Rooting rate, root length and seedling height of seedling were the highest under 10% PEG treatment, which were 1.14, 1.05, 1.24 and 1.33 times of the control, respectively, except for the rate of rooting, the other indexes were significantly different from the control P <0.01). Soluble protein and chlorophyll increased firstly and then decreased, but MDA content and relative conductivity decreased firstly and then increased, and the best ones were 15% PEG, which were 1.38, 1.84 and 0.65 0.71-fold higher than that of the control (P <0.01). 2) When the seedlings were heavily stressed with 30% PEG, their leaf protein and chlorophyll content decreased by 42.11% and 38.98% Compared with the stress control group, the relative electrical conductivity and the content of malondialdehyde increased by 28.24% and 6.04%, respectively, compared with those of the control group. However, after 15% PEG pretreatment The content of both treatments decreased by 28.64% and 33.41% compared with the control group. The results showed that PEG with low mass fraction promoted the seed germination and the physiological characteristics of seedling growth. The high concentration of PEG treatment inhibited the plant growth.