硅对镉胁迫下水稻幼苗不同叶位叶片叶绿素含量的影响

Effect of Silicon on Chlorophyll Contents of Rice Seedlings at Different Position under Cadmium Stress

通过溶液培养,研究不同硅浓度（0、30、80、130、180 mg.L-1SiO2）对镉（4.0 mg.L-1Cd2＋）胁迫下水稻幼苗不同叶位叶片叶绿素a、叶绿素b和总叶绿素含量的影响。结果表明：30~130 mg.L-1SiO2可提高对镉胁迫下水稻幼苗倒5、倒4叶位叶片3种色素含量,且130 mg.L-1SiO2均达到最佳效果,其中倒5叶位叶片3种色素含量分别较单独镉胁迫下提高189.47%、38.66%和75.93%,而倒4叶位叶片中叶绿素a、叶绿素b、总叶绿素含量在130 mg.L-1SiO2分别为单独镉胁迫下的161.15%、166.23%和177.61%,但较高浓度（〉130mg.L-1SiO2）时水稻幼苗倒5、倒4叶位叶片叶绿素含量却呈现下降趋势;水稻幼苗倒3叶位叶片3种色素含量均随着SiO2浓度的增加而呈上升趋势,当SiO2浓度为180 mg.L-1时,3种色素含量达到最高（2.5239、0.8120、3.3359 mg.g-1.FW）;而硅对镉胁迫下水稻幼苗倒3、倒2、倒1叶位叶片3种色素含量影响较小,未及倒5、倒4等下位叶的影响显著。

Effect of silicon on chlorophyll a, chlorophyll b and total chlorophyll contents of rice seedlings at different position under cadmium stress were studied by hydroponics culture method. Rice seedlings were treated with the concentration of 4.0 mg·L-1 Cd2＋ and 0, 30, 80, 130, 180 mg·L-1 SiO2. The resuits showed that three chlorophyll content in the 5th and the 4th leaf from the top of rice seedlings under cadmium stress increased when the concentration of silicon was 30-130 mg·L-1 SiO2, and they were the most at 130 mg·L-1 SiO2. The chlorophyll a, chlorophyll b and total chlorophyll contents of the 5th leaf from the top increased 189.47%, 38.66% and 75.93%, and that of the 4th leaf from the top increased 161.15%, 166.23% and 177.61% compared with cadmium stress. When the concentration of silicon was more than 130 mg·L-1 SiO2, the chlorophyll content of the fifth and the 4th leaf from the top decreased. The three chlorophyll content of the 3rd leaf from the top increased with the increase of SiO2 concentration. When the SiO2 concentration was 180 mg·L-1, the three chlorophyll content were the highest （2.5239, 0.8120, 3.3359 mg·L-1FW）.The effect of silicon on three chlorophyll content of the 3rd, the second and the first leaf from the top of rice seedlings under cadmium stress was less significant than on the 5th and the 4th leaf from the top of rice seedling.