镉胁迫对抽穗期水稻生理生化特性的影响

目的]研究抽穗期镉胁迫对不同水稻生理生化的影响。方法]采用土培法,研究镉胁迫(镉离子浓度为0、50和100μmol/L)下4个水稻品种(盐粳7号、楚粳香1号、嘉育253、南恢511)生理生化指标的变化,包括SOD、POD、CAT保护酶、丙二醛、脯氨酸、可溶性糖、叶绿素、光合速率等。结果]4个品种SOD酶活性在镉胁迫下极不稳定,低浓度镉处理下,嘉育253和盐粳7号的SOD活性分别下降54.62%、29.60%,高浓度镉处理下分别增加47.58%、29.20%,楚粳优1号在表现为低促高浓抑的现象;在低浓度镉处理下楚粳优1号和嘉育253的POD活性下降最明显,不同品种间差异显著;高镉处理下,盐粳7号CAT活性较对照增加101.2%;盐粳7号在高浓度镉处理下脯氨酸含量与对照相比增加了74%,不同浓度之间差异显著;4个品种的MDA变化趋势基本一致,盐粳7号和南恢511在低浓度镉处理下MDA含量分别下降7.4%、2.0%。随着镉浓度增加,2个品种的MDA含量与低浓相比分别增加5.0%、1.9%。镉胁迫下不同品种叶绿素a、叶绿素b、叶绿素总量的反应不同,总体上变化不明显。盐粳7号在高浓度镉处理下脯氨酸含量与对照相比增加了74%,不同浓度之间差异显著。结论]该研究为生产安全无公害稻米提供技术基础和科学依据。

Effects of Cadmium Stress on the Physiological and Biochemical Characters of Rice at Heading Stage

Objective] To research the effects of cadmium stress on the physiological and biochemical characters of rice at heading stage.Meth-od] Soil culture method was adopted.We researched the changes of physiological and biochemical characters of four rice varieties (Yanjing 7, Chujingxiang 1,Jiayu 253,Nanhui 511) under the stess of cadmium(cadmium concentration 0,50 and 100 μmol/L),including SOD,POD,CAT protective enzyme,malonaldehyde,proline,soluble sugar,chlorophyll and photosynthetic rate.Result] The SOD activities of 4 varieties were highly unstable under cadmium stress.At low concentrations of cadmium,SOD activity of Jiayu 253 and Yanjing 7 dropped to 54.62%,29.6%, respectively.At high concentrations of cadmium,they increased to 47.58%,29.2%,respectively.At low concentrations,SOD of Chujingyou 1 was promoted,but it was inhibited at high concentrations.At low concentrations of cadmium,POD activity of Chujingyou 1 and Jiayu 253 decreased most obviously,and there were significant differences among varieties.At high concentrations of cadmium,CAT activity of Yanjing 7 was increased by 101.2% compared with the control group.The proline content of Yanjing 7 was increased by 74% compared with the control group at high concentrations of cadmium,and there were significant differences among varieties.The MDA variation trend of 4 varieties was basically consistent. The MDA content decreased by 7.4% and 2.0%,respectively,in the treatment of low concentration of cadmium.With the increase of cadmium concentration,MDA content of two varieties increased by 5.0% and 1.9%,respectively.The reactions of chlorophyll a,chlorophyll b and chloro-phyll in different varieties under cadmium stress were different,and the overall change was not obvious.Compared with the control group,proline content of Yanjing 7 increased by 74%,and the difference was significant.Conclusion] This research provided technical and scientific basis for the production of safe and harmless rice.