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为探索聚乙二醇(Polyethylene glycol,PEG)引发种子对高粱芽苗耐水分亏缺的生理调节效应,通过盆栽土培试验,将高粱种子(辽粘6号)采用20%的PEG 8000溶液,在18℃条件下浸泡48h,设置土壤100%(CK)、85%、70%、55%和40%供水量模拟水分亏缺,研究种子萌发、相对含水量、叶绿素、根系活力、抗氧化系统、渗透调节系统和根系解剖结构等的适应特点与调节方式。结果表明:1)PEG引发种子可促进水分亏缺下种子的萌发、增强种子的活力和促进出苗;2)PEG引发种子对幼苗地下部的作用效果大于地上部,在土壤水分亏缺不超过70%供水(Soil water content,SWC-70)时叶绿素降解和根系活力降低幅度较小;3)PEG引发种子后抗氧化系统和渗透调节系统均发生较大变化,POD和O2-是维持水分亏缺的抗氧化系统关键因子,可溶性糖和质膜透性的调节是提高幼苗机体抗性的重要因素;4)种子引发对根系后生木质部和后生韧皮部数量和体积的调节是其适应水分亏缺的重要方式。土壤水分亏缺条件下合理应用聚乙二醇(PEG)引发种子可以有效提高高粱芽苗期的抗旱能力。
In order to explore the physiological regulation effect of polyethylene glycol (PEG) on the water deficit tolerance of sorghum sprouts, sorghum seed (Liaoyu No.6) was treated with 20% PEG 8000 by pot culture. The soil water deficit was simulated by 100% (CK), 85%, 70%, 55% and 40% water supply at 18 ℃ for 48h. The seed germination, relative water content, chlorophyll, root activity, antioxidant system , Osmotic adjustment system and root anatomy and other adaptation characteristics and methods of regulation. The results showed that: 1) PEG induced seed germination could promote the seed germination under water deficit, enhance seed vigor and promote seedling emergence; 2) The effect of PEG-induced seedling seedling’s underground was greater than that of aerial part, The decrease of chlorophyll and root vigor was less when% soil water content (SWC-70) was applied; 3) Both antioxidant system and osmotic adjustment system changed greatly after PEG-induced seed, POD and O2- The regulation of soluble sugar and plasma membrane permeability is one of the most important factors to improve the resistance of seedlings to seedlings. 4) The regulation of the number and the volume of seedlings induced by seed initiation on the xylem and epigenetic phloem of roots is important to adapt to water deficit the way. Reasonable application of polyethylene glycol (PEG) -introducing seed under soil water deficit condition can effectively increase the drought resistance of sorghum sprouts.