水分胁迫下小麦品种间几类渗透调节物质积累的比较研究

 试验采用10%和15%两种PEG溶液浓度,比较了三个抗旱性不同品种的小麦幼苗在水分胁迫期间可溶性糖、蔗糖、有机酸和氨基酸等渗透调节物质的动态变化和积累差异.结果表明,水分胁迫初期可溶性糖及蔗糖含量下降、然后上升、积累,并且同一品种10%PEG胁迫可溶性糖总量积累高于15%PEG胁迫,蔗糖积累情况相反.糖分积累的程度存在着品种间差异.PEG引起的水分胁迫使科拜和祥云爬地麦的有机酸总量有不同程度降低,云麦29则有不同程度增加.氨基酸总量分析揭示,抗性品种比敏感品种积累更多的氨基酸.试验还观察到,15%PEG胁迫能迅速导致三个品种的Leu+Phe的积累,而10%PEG胁迫的积累情况随品种而异.此外,还比较分析了脯氨酸、天冬氨酸、天冬酰胺,谷氨酸,异亮氨酸等个别氨基酸在不同品种,不同胁迫以及不同时间进程中的消长变化.水分胁迫引起的溶质积累,在种类,数量和速率方面存在着明显的品种间差异.与干旱敏感品种相比,抗性品种具有更强的渗透调节能力.

A Comparative Study on Some Osmotic Adjustment Substances Accumalation Between Wheat(T.aestivum)Varieties Under Water Stress

In this study,the trends,the accumulative differences of some osmotic adjustment sub- stances,soluble sugar,sucrose,organic acids and amino acids,in three varieties' seedlings of wheat with different drought resistance,were compared during osmotic stress in which two concentration,10% and 15%,of PEG(6000)solution were adopted.The results indicated that the contents of soluble sugars and sucrose decreased in early stage of water stress,then increased and accumulated,and the total soluble sugars accumulated by the same variety under 10% PEG stress was more than under 15% PEG s-tress,and the situation was reverse to sucorse.Sugar accumulation varied with varieties.Under water stress caused by PEG,the total content of organic acids reduced in Ke-bai and Xiangyun Pa-di-mai,whereas in- creased in Yun-Mai 29 at different degrees.The analysis of total content of amino acids showed that the drought-resistance wheat accumulated more amino acids than the drought-sensitive one. It was observed in the experiment that 15% PEG stress could quickly result in Leu+Phe accumulating in three varieties,but 10% PEG stress caused accumulation differed with the varieties.In addtion,the changes of proline,aspartate,asparagine,glutamate,isoleucine were analysed and compared between different varieties under different stress and time courses. It was obvious that the kinds,quantities,and accumulation rate of solutes under water stress were quite different between varieties.Compared with the drought-sensitive one, drought-resistant wheat possessed more potential ability of osmotic adjustment.