干旱胁迫下外源硅对蒙古黄芪幼苗生理生化特性的影响

王惠珍，陆国弟，胡茹英，孙强，陈红刚，王引权

甘肃中医药大学，甘肃 兰州 730000

摘要：目的 研究不同处理条件下蒙古黄芪幼苗的生理特性变化，探讨干旱胁迫下外源硅对蒙古黄芪幼苗影响的生理机制。方法 采用沙培试验，设置3个聚乙二醇模拟浓度和3个硅浓度，测定不同条件下蒙古黄芪幼苗叶绿素、丙二醛、渗透调节物质、抗氧化酶指标，研究干旱胁迫下外源硅对蒙古黄芪幼苗生理生化特性的影响。结果 随干旱胁迫增加，叶绿素总量和叶绿素a呈先增加后降低趋势，叶绿素b呈降低趋势；加入外源硅使叶绿素含量呈显著增加趋势。随干旱胁迫增加，丙二醛含量呈增加趋势，重度、中度胁迫分别较对照增加

53.7%、40.6%；加入外源硅可减少丙二醛含量。随干旱胁迫增加，游离脯氨酸（Pro）呈增加趋势，中度胁迫为对照的 1.7倍，重度胁迫分别为对照、中度胁迫的3.5、2.1 倍；加入外源硅可使重度胁迫下Pro 含量显著升高。随干旱胁迫增加，超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）活性整体呈增加趋势；加入外源硅使SOD活性降低但不显著，POD在中度胁迫下显著降低，CAT在重度胁迫下显著降低。且以硅浓度为6 mmol/L 时作用最明显。结论 在干旱胁迫下，外源硅可使Pro处于更高水平，降低丙二醛含量，提高抗氧化酶活性，促进叶绿素合成，有利于蒙古黄芪幼苗生长。关键词：蒙古黄芪；干旱胁迫；硅；渗透调节物质；丙二醛；抗氧化酶

中图分类号：R282.2 文献标识码：A 文章编号：1005-5304(2020)03-0067-04

DOI：10.3969/j.issn.1005-5304.201903322 开放科学（资源服务）标识码（OSID）：

Effects of Silicon on Physiological and Biochemical Characteristics of Astragalus membranaceus Seedlings under Drought Stress

WANG Huizhen, LU Guodi, HU Ruying, SUN Qiang, CHEN Honggang, WANG Yinquan

Gansu University of Chinese Medicine, Lanzhou 730000, China

Abstract: Objective To study changes of physiological characteristics of Astragalus membranaceus seedlings under drought stress; To explore the physiological mechanism of silicon on seedlings of Astragalus membranaceus under drought stress. Methods Sand culture test was adopted. The effects of silicon on physiological and biochemical characteristics of Astragalus membranaceus seedlings under drought stress were studied by measuring chlorophyll, MDA, osmotic regulators and antioxidant enzymes in three PEG-6000 simulated concentrations and three silicon concentrations. Results With the increase of drought stress, the total contents of chlorophyll and chlorophyll a of seedlings increased at first and then decreased, and chlorophyll b decreased, and the chlorophyll content increased significantly with the addition of silicon. MDA increased by 53.7% and 40.6% under severe and moderate stress compared with CK, respectively; Silicon could reduce MDA production. Proline showed an increasing trend with the increase of drought stress. Moderate stress was 1.7 times as much as CK, and severe stress was 3.5 times and 2.1 times as much as CK and moderate stress; Silicon addition could significantly increase Proline content under severe stress. The activities of three antioxidant enzymes (SOD, POD and CAT) in seedlings increased as a whole with the increase of drought stress. With the addition of silicon, the activities of SOD decreased. POD decreased significantly under moderate stress, and CAT decreased significantly under severe stress. The most significant effect appeared when the concentration of silicon was 6 mmol/L. Conclusion Under drought stress, the application of silicon can make Proline at a higher level, reduce the content of MDA, increase the activity of antioxidant enzymes, and promote chlorophyll synthesis, which is beneficial to the growth of Astragalus membranaceus seedlings under drought stress.

基金项目：西北中藏药协同中心项目（XBXT2015-4）；甘肃省青年科技基金计划（17JR5RA166）；现代农业技术体系专项资金

（CARS-21）

Keywords: Astragalus membranaceus; drought stress; silicon; osmotic regulators; malondialdehyde; antioxidant enzymes

蒙古黄芪 Astragalus membranaceus（Fish）Bge. var. Mongholicus（Bunge）Hsiao 为十大陇药之一，具

有补气升阳、固表止汗、利水消肿、敛疫生肌等功效[1]，

目前主要分布在中国西北部干旱和半干旱地区，90%来源于人工栽培。干旱为西北地区影响植物体生长发育的主要因素，对植物造成的损失在所有非生物因素中居首位。甘肃省是蒙古黄芪的重要产区，干旱缺水严重影响蒙古黄芪产量和质量，是制约其产业发展的主要因素之一。硅是植物生长的有益元素，研究表明，硅可在一定程度上缓解干旱胁迫对植物生长发育造成的影响，施用硅肥有望成为提高干旱或半干旱地区

作物产量的重要手段[2]。已有在甘草[3]、番茄[4]、水

稻[5]、早熟禾[6]、紫花苜蓿[7]、草莓[8]、野生大豆[9]及

小麦[10]等植物上进行硅对植物抗旱性影响的研究报道，而硅参与蒙古黄芪抗旱性的研究鲜见。因此，本试验以2年生蒙古黄芪种子为材料，探讨干旱胁迫下介外源硅的加入对蒙古黄芪幼苗生理特性的影响，为干旱及半干旱区蒙古黄芪的规范化种植及硅肥的施用提供参考。

仪器与试药型紫外可见分光光度计，青岛智汇谷信息

智能型人工气候箱，宁波

养皿中，每个培养皿精选大小均匀一致种子 80 粒，摆放间距为种子大小的2 倍，置于 25 ℃恒温、12 h光暗交替、相对湿度 70%的 RXZ 智能型人工气候箱内培养。釆用称重法每日定时补充蒸散的水分以维持溶液渗透势恒定，将培养皿每日按一定的空间顺序上下交换位置，第10日取样测定幼苗生理特性指标。

2.2 指标测定采用丙酮提取法测定叶绿素含量，硫代巴比妥酸

法测定丙二醛含量[11-12]，蒽酮比色法测定可溶性糖

（SS）含量[12-13]，酸性茚三酮比色法测定游离脯氨酸

（Pro）含量[12，14]，愈创木酚法测定过氧化物酶（POD）

活性[12，15]，氮蓝四唑（NBT）法测定超氧化物歧化酶

（SOD）活性[12，16]，过氧化氢分解法测定过氧化氢酶

（CAT）活性[17]。

2.3 统计学方法

采用 SPSS22.0 统计软件进行分析。计量资料用x±s 表示，组间比较采用新复极差法（SSR 法）做显

—

著性测验。P＜0.05表示差异有统计学意义。