土壤加砷对大豆叶绿素、脯氨酸和过氧化氢酶活性的影响

为了认识土壤砷污染对大豆生理指标的影响,设置土壤加砷0、5、10、30、50和100mg kg-1共6个水平的盆栽大豆试验,测定大豆生长期间叶片的叶绿素、脯氨酸含量和过氧化氢酶活性等生理指标.结果表明,土壤砷污染影响大豆的叶绿素、脯氨酸、过氧化氢酶等生理指标.土壤加砷对大豆叶绿素的影响随生长期而不同,在结荚期,土壤加砷对叶绿素含量的影响不显著,但是高砷水平降低了叶绿素a与b的比值;在鼓粒期,高砷水平增加了大豆的叶绿素含量,叶绿素a、叶绿素b、类胡萝卜素和叶绿素总量的最大增加率分别达119.8%、111.0%、105.6%和117.2%.在大豆结荚期,土壤加砷30～100mg kg-1使大豆脯氨酸的含量降低了23.4%～31.4%,而所有加砷处理的过氧化氢酶活性都显著低于对照,土壤加砷使大豆过氧化氢酶活性降低了10.7%～46.6%.总之,土壤砷污染会通过影响叶绿素的构成和含量改变大豆光合作用、降低大豆抗逆性和破坏大豆抗氧化系统来妨碍大豆的生长.

Effects of soil arsenic additions on chlorophyll, proline and the catalase activity in soybean (Glycine max .L .)

In order to understand the effects of soil arsenic pollution on soybean（Glycine max.L.） physiological indexes,a soil pot experiment cultivating soybean by soil arsenic additions of 0,5,10,30,50 and 100 mg kg-1 was conducted and the content of chlorophyll and proline and the activity of catalase was determined during the soybean growing.The results showed that soil arsenic additions had significant effects on chlorophyll,proline and catalase in soybean leaves.The effects of arsenic on chlorophyll in soybean leaves varied with the growing stages.At the pod stage,the content of chlorophyll in soybean leaves was not significantly influenced by soil arsenic additions,but the ratios of chlorophyll a to b in 50 and 100 mg kg-1 arsenic additions were significant lower than that in control.While at grain filling stage,soil arsenic additions of 50 and 100 mg kg-1 increased the chlorophyll content in soybean leaves significantly and the highest increasing rate of chlorophyll a,chlorophyll b,carotenoid and the total chlorophyll was 119.8%,111.0%,105.6% and 117.2%,respectively.At pod stage,soil arsenic additions of 30—500 mg kg-1 decreased 23.4%—31.4% of proline content in soybean leaves,but the activity of catalase in soybean leaves at the soil arsenic additions was significant lower than that at control and was reduced 10.7%—46.6% by soil arsenic additions.In conclusion,soil arsenic pollution may hinder the soybean growth by influencing the content and constitute of chlorophyll,altering the photosynthesis,reducing the resistance and destroying the ant-oxidative system of soybean.