八宝叶片对干旱胁迫的生理响应

Physiological response of Hylotelephium erythrostictum leaves to drought stress

【目的】研究八宝叶片对干旱胁迫的生理响应,为揭示八宝的抗旱机理及其应用提供依据。【方法】以八宝水培幼苗为材料,经10%、20%、30%和40%的PEG6000处理0、3、6、9、15、20、25、30 d后,测定叶片相对含水量、相对电导率、丙二醛、可溶性糖和脯氨酸五个生理指标的变化。【结果】在20%、30%和40%PEG胁迫下,相对含水量随着胁迫时间的延长和处理浓度的增加而呈现下降趋势,但是在胁迫的3 d至30 d期间,10%PEG胁迫下的相对含水量始终高于比对照;相对电导率随着胁迫时间的延长和处理浓度的增加而呈现升高趋势,在40%PEG胁迫30 d时相对电导率达到最高,约为对照的1.56倍;丙二醛含量同样随着处理浓度的增加和胁迫时间的延长而增加,在40%PEG胁迫30 d时的含量最高,为对照的4.88倍;可溶性糖含量和脯氨酸含量均随着胁迫程度的增加和时间的延长而增加,在40%PEG胁迫30 d时脯氨酸含量为对照的13.99倍,而可溶性糖含量仅为对照的1.99倍。【结论】八宝在干旱胁迫下叶片相对含水量降低,细胞膜受损明显,渗透调节物质增加,并且主要通过提高脯氨酸的含量提高耐旱性。

【Objective】The physiological response of Hylotelephium erythrostictum(Miq.)H.Ohba eaves to drought stress was studied to provide the basis for revealing the drought resistance mechanism of H.erythrostictum and its application.【Methods】H.erythrostictum hydroponic seedlings were used as materials.After 0,3,6,9,15,20,25,and 30 days of treatment with 10%,20%,30%,and 40% PEG6000 the leaves were collected.The relative water content,relative electrical conductivity,MDA content,soluble sugar content,and proline content were examined.【Results】It was found that under 20%,30%,and 40% PEG,the relative water contents of leaves decreased with the increase of stress time and PEG concentration.However,after treatment for 3 d to 30 d under 10% PEG,the relative water contents were higher than the control.The relative electrical conductivities increased with the enhancement of stress time and PEG concentration.The highest relative electrical conductivity occurred under 40% PEG after 30 d treatment,which was about 1.56-fold of the control.MDA contents also increased with stress concentration and time.MDA contents exhibited the highest value after 30 d treatment with 40% PEG,which was 4.88-fold of the control.The soluble sugar contents and proline contents increased with stress concentration and time.After treatment with 40% PEG for 30 d,the proline content was 13.99-fold of the control,while the soluble sugar content was only 1.99-fold of the control.【Conclusion】Exposure to the drought stress,the relative water contents of the leaves in H.erythrostictum reduced,and the cell membrane was damaged seriously.Moreover,the contents of osmotic adjustment substances increased,and the drought tolerance was primarily improved by increasing proline contents.