PEG6000渗透胁迫对藜幼苗叶片渗透调节物质的影响

Effect of Osmotic Stress with PEG6000 on Osmotic Adjustment Solute in Seedling Leaves of Chenopodium album L.

[目的]为了探讨藜的耐旱机理,为藜的人工栽培及推广提供理论依据和实践指导。[方法]藜幼苗长到六叶期时,浓度分别为0、5%、10%、20%的PEG6000进行渗透胁迫处理,分别处理01、、35、、7和9 d后从植株上部第3～5叶片功能叶片进行各项生理指标的测定。[结果]在5%PEG胁迫下,藜幼苗叶片的渗透调节物质含量缓慢增加,相对含水量（RWC）下降较小,在10%、20%PEG胁迫下,可溶性蛋白质、甜菜碱含量先升后降,RWC下降幅度较大。10%PEG胁迫的第5天藜幼苗叶片RWC降到62%,叶片开始萎焉;20%PEG胁迫的第3天RWC降到61.9%,叶片开始出现萎焉现象,第7天RWC降到48.6%,叶片干黄。5%、10%2、0%PEG胁迫到第7天时藜幼苗叶片脯氨酸含量分别是对照的7.64、10.92、9.4倍。[结论]藜对适度的渗透胁迫具有一定的适应性,但高浓度、长时间的PEG渗透胁迫会对藜造成严重损伤。

[Objective] The purpose was to discuss drought resistance mechanism of Chenopodium album L.and supply theoretical basis and practical guidance for artificial cultivation and popularization of C.album.[Method] C.album seedlings grown to 6th leaf stage were treated by PEG6000 osmotic stress with concentrations of 0,5%,10% and 20% and the various physiological indexes of the 3th ～5th function leaves in upper plant were determined after treating for 0,1,3,5,7 and 9 days.[Result] Under osmotic stress with 5% PGE,the osmotic adjustment solute content in seedling leaves of C.album increased slowly and the relative water content（RWC） reduced less.Under osmotic stress with 10% and 20% PGE,the soluble protein and lycine contents first increased and then decreased and the RWC decreased in greater range.Under osmotic stress with 10%,the RWC in seedling leaves of C.album decreased to 62% at the fifth day and the leaves began to wither.Under osmotic stress with 20%,the RWC in seedling leaves of C.album decreased to 61.9% at the third day and the leaves appeared withering,and the RWC decreased to 48.6% at the 7th day and the leaves were dry and yellow.Proline contents in seedling leaves of C.album under osmotic stress with 5%,10% and 20% PEG were 7.64,10.9 and 29.4 times of CK at the 7th day.[Conclusion] C.album had some adaptability to moderate osmotic stress,but the PEG osmotic stress with high concentration and long time might lead to severe damage on C.album.