腐殖质对干旱胁迫下多花黄精叶片生理生化特性的影响

Effects of humus on physiological and biochemical characters of Polygonatum cyrtonema leaves under drought stress

【目的】通过研究干旱胁迫下多花黄精生理生化指标的变化,综合评价腐殖质对其抵御干旱胁迫的影响,为多花黄精节水栽培提供理论依据。【方法】采用盆栽实验,分别以腐殖质土和黄土(对照基质)为培养基质,设置正常供水(土壤含水量80%~85%)、轻度干旱(土壤含水量60%~65%)、中度干旱(土壤含水量40%~45%)、重度干旱(土壤含水量20%~25%)4个控水梯度,测定多花黄精叶片相对电导率、丙二醛含量、可溶性糖含量、可溶性蛋白含量、超氧化物歧化酶活性和过氧化物酶活性等生理生化指标的变化。【结果】轻度干旱胁迫不会导致多花黄精叶片生理生化抗旱指标发生明显变化;中度干旱胁迫对多花黄精叶片生理生化产生较明显影响,腐殖质土基质中多花黄精叶片相对含水量、叶绿素含量、SOD活性、POD活性比对照基质分别少下降0.34%、4.99%、18.37%、2.90%,相对电导率、MDA含量分别少增加10.30%、9.12%,可溶性糖含量、可溶性蛋白含量分别多增加3.60%、1.79%;重度干旱胁迫对多花黄精叶片生理生化产生明显影响,腐殖质土基质下多花黄精叶片的相对含水量、叶绿素含量、SOD活性、POD活性比对照基质分别少降低2.16%、5.14%、19.92%、8.56%,相对电导率、MDA含量分别少增加14.16%、16.86%,可溶性糖含量、可溶性蛋白含量分别多增加4.06%、2.35%。隶属函数法综合评判得出腐殖质土基质栽培下多花黄精抗旱隶属函数值比对照基质提高了151%。【结论】腐殖质作为多花黄精促生长的栽培基质,在干旱胁迫下可提高多花黄精生理生化抗旱指标的稳定性,并通过增加渗透调节物质含量的方式在一定程度上抵御干旱胁迫。

【Objective】By studying the changes of physiological and biochemical indicators of Polygonatum cyrtonema under drought stress,and comprehensively evaluating the impact of humus on its resistance to drought stress,a theoretical basis for water-saving cultivation of P.cyrtonema was provided.【Method】Using humus and loess(control)as the culture medium,the pot experiment was conducted to determine the relative water content,chlorophyll content,relative conductivity,malondialdehyde content,soluble sugar content of P.cyrtonema leaves by setting four water supply gradients:normal water supply(soil water content 80%-85%),mild drought(soil water content 60%-65%),moderate drought(soil water content 40%-45%),and severe drought(soil water content 20%-25%).Changes of physiological and biochemical indexes such as relative water content,chlorophyll content,relative conductivity,malondialdehyde content,soluble sugar content,soluble protein content,superoxide dismutase activity and peroxidase activity in P.cyrtonema leaves were measured.【Result】Mild drought stress did not cause significant changes in physiological and biochemical drought resistance indicators of P.cyrtonema leaves.Moderate drought stress had a significant impact on the physiology and biochemistry of P.cyrtonema leaves,among which the relative water content,chlorophyll content,SOD activity and POD activity in humus soil matrix were respectively decreased by 0.34%,4.99%,18.37%,2.90%less than those in the control matrix,but the relative conductivity and MDA content were respectively increased by 10.30%and 9.12%less than those in the control matrix,and the soluble sugar content and soluble protein content were respectively increased by 3.60%and 1.79%more than those in control matrix.Severe drought stress had a significant impact on the physiology and biochemistry of P.cyrtonema leaves,among which the relative water content,chlorophyll content,SOD activity,POD activity in Humus soil matrix were respectively decreased by 2.16%,5.14%,19.92%and 8.56%less than those in the control matrix,but the relative conductivity and MDA content were respectively increased by 14.16%and 16.86%less than those in the control matrix,and the soluble sugar content and soluble protein content were respectively increased 4.06%and 2.35%more than those in the control matrix.The comprehensive evaluation of the subordinate function showed that the drought resistance subordinate function value of P.cyrtonema in the humus soil substrate culture was 151%higher than that of the control substrate.【Conclusion】As a cultivation substrate for promoting the growth of P.cyrtonema,humus can improve the stability of physiological and biochemical drought resistance indicators of P.cyrtonema under drought stress,and can resist drought stress to a certain extent by increasing the content of osmoregulation substances.