PEG-6000模拟干旱胁迫对小叶黑柴胡幼苗生理特性的影响

Effects of PEG-6000 Simulated Drought Stress on Physiological Characteristics of Bupleurum smithii var.Parvifolium Seedlings

通过探讨小叶黑柴胡对干旱胁迫的响应,为综合评价小叶黑柴胡的耐旱性提供科学依据,进而为大田栽培提供技术指导。以小叶黑柴胡幼苗为试验材料,采用PEG-6000模拟干旱胁迫方法,研究了干旱胁迫对其叶片抗氧化酶活性、细胞膜透性及渗透调节物质等生理指标的影响。结果表明,随着PEG-6000胁迫浓度(0~25%)的升高,小叶黑柴胡叶片中超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、过氧化氢酶(CAT)活性、丙二醛(MDA)含量、游离脯氨酸(Pro)含量及可溶性糖含量变化表现较为一致,均呈现先升高后下降的趋势,但峰值略有不同,MDA含量呈现持续上升趋势至PEG-6000胁迫最高浓度(25%)。综合分析认为,小叶黑柴胡具有一定的抗旱性,在适度的干旱胁迫下可以保持一定的抗渗透胁迫能力和清除活性氧的能力,进而保持膜的稳定。

By exploring the response of Bupleurum smithi var.parvifolium to drought stress,this study provides scientific evidence for comprehensively evaluating its drought tolerance,further offering technical guidance for field cultivation.Using Bupleurum smithi var.parvifolium seedlings as experimental materials,the drought stress was simulated with PEG-6000,and the effects of drought on leaf antioxidant enzyme activity,cell membrane permeability,and osmotic regulatory substances were studied.The results showed that with increasing PEG-6000 concentrations(0 to 25%),the activities of superoxide dismutase(SOD),peroxidase(POD),catalase(CAT),as well as contents of malondialdehyde(MDA),free proline(Pro),and soluble sugar in the leaves all exhibited similar trends,first increasing and then decreasing,although the peak values varied slightly.The MDA content continued to increase as the PEG-6000 stress reached its highest concentration(25%).Overall,the study concluded that Bupleurum smithi var.parvifolium possesses certain drought tolerance and can maintain osmotic stress resistance and reactive oxygen species scavenging abilities under moderate drought stress,thereby maintaining membrane stability.