PEG胁迫对2个青稞新品系种子萌发和幼苗生理生化特性的影响

Effects of PEG Stress on Seed Germination and Seedling Physiological and Biochemical Characteristics of Two New Highland Barley Lines

【目的】研究干旱对青稞种子萌发和幼苗生长的影响,提高青稞幼苗在干旱环境中的成活率。【方法】以滇青1号和滇青2号为材料,设置不同PEG质量分数梯度(0%、5%、10%、15%、20%和25%),测定其种子萌发和幼苗的生理生化特性,分析2个青稞新品系对干旱的响应规律。【结果】适宜质量分数(5%)的PEG有利于促进青稞种子萌发和幼苗生长。随着干旱程度增加,丙二醛、可溶性蛋白和游离脯氨酸含量以及SOD活性等明显增加,干旱处理下青稞根系的生理生化变化相对于地上部分明显;滇青2号的种子发芽指标低于滇青1号,幼苗生理生化变化多高于滇青1号,即滇青2号受干旱影响更大,滇青1号幼苗的抗旱能力较强。【结论】5%PEG有利于滇青1号和滇青2号种子萌发和幼苗生长,且滇青1号抗旱能力较滇青2号强。

[Purpose]To study the effects of drought on the seed germination and seedling growth of highland barley,and to improve the survival rate of highland barley seedlings in arid environment.[Method]Using Dianqing No.1 and Dianqing No.2 as materials,different PEG mass fraction gradients(0%,5%,10%,15%,20%and 25%)were used to determine the physiology of seed germin-ation and seedlings.Biochemical characteristics were used to analyze the response law of two new highland barley lines to drought.[Results]The suitable mass fraction(5%)of PEG was beneficial to promote highland barley seed germination and seedling growth.With the increase of the degree of drought,the content of malondialdehyde,soluble protein and free proline,and SOD activity also in-creased obviously.The physiological and biochemical changes of highland barley roots under drought treatment were more obvious than those of the aboveground parts;the seeds of Dianqing No.2 ger-minated indexes were lower than that of Dianqing No.1,and the physiological and biochemical changes of seedlings were higher than those of Dianqing No.1,that was,Dianqing No.2 was more af-fected by drought,and Dianqing No.1 seedlings had stronger drought resistance.[Conclusion]5%PEG treatment is beneficial to seed germination and seedling growth of Dianqing No.1 and Dianqing No.2,and Dianqing No.1 has better drought resistance than Dianqing No.2.