摘要：采用水培的方法本文研究了不同浓度梯度下Mg2+、K+对小麦幼苗（Triticum aestivum）生长的影响，测定小麦的根冠比、鲜重干重比、叶绿素含量、可溶性糖含量、丙二醛含量、POD酶活性。观察发现，在缺镁条件下(Mg2+浓度为0g/L)小麦生长受到严重影响，供镁不足（Mg2+浓度小于0.06g/L）条件下根冠比高于对照组（浓度等于0.06g/L）表明供镁不足虽促进根系生长但抑制地上部分的生长，鲜重干重比、叶绿素含量、可溶性糖含量均低于对照组，丙二醛含量、POD酶活性均高于对照组。在缺钾（K+浓度为0g/L）和供钾不足（K+浓度小于0.24g/L）时根冠比高于对照组（K+浓度等于0.24g/L），随着钾离子浓度的增大根冠比有下降的趋势，鲜重干重比、叶绿素含量、可溶性糖含量均低于对照组，丙二醛含量、POD酶活性均高于对照组。结果表明缺钾和供钾不足时小麦幼苗的新陈代谢水平相对较低。

关键词：小麦幼苗、Mg2+、K+

Abstract: With the water culture method ,it researched the influence of different consistency of Mg2+、K+ on the growth of wheat seedlings. Test the ratio of root to crown of the wheat, ratio of fresh weight to dry weight, content of chlorophyll, soluble sugar, MDA and activity of POD. Observed that: as the Mg2+ consistency were 0g/L severely affected the growth of wheat, the inhibition is obvious. When magnesium was deficient (Mg2+concentration <0.06g/L), the ratio of root to crown increased. It showed that Promoting root growth and restraining the other parts growth happened when magnesium was deficient. The ratio of fresh weight to dry weight, content of chlorophyll, soluble sugar, was lower than the control group. Content of MDA and activity of POD were higher than normal. When K+ consistency were 0g/L and deficient (K+ concentration <0.06g/L) the ratio of root to crown higher than the control group. With the increase of potassium ion concentration the ratio of root to crown has declined, the ratio of fresh weight to dry weight, content of chlorophyll, soluble sugar were lower than the control group, MDA content, POD activity were higher. The results showed that when K+ concentration were 0g/L and deficient (K+ concentration <0.06g/L) the metabolism of wheat seedlings are relatively lower.

Key words: wheat seedlings, Mg2+, K+