盐旱交叉胁迫对蒙古黄芪幼苗生长发育及总黄酮成分积累的影响

Effects of Salt and Drought Cross Stress on Growth and Development and Accumulation of Total Flavonoids in Astragalus membranaceus var.mongholicus Seedlings

目的:探究盐旱双重因子对蒙古黄芪幼苗生长、生理特性及总黄酮成分积累的影响,以期能够指导黄芪的规范化种植。方法:以一年生蒙古黄芪为试材,设置了16个水平的盐旱胁迫条件,研究了对蒙古黄芪幼苗生长、抗氧化酶类(SOD、POD、CAT)活性、渗透调节物质(脯氨酸、可溶性糖)含量及总黄酮积累的影响。结果:盐旱胁迫后,地上及地下部生物量均降低;抗氧化酶类活性随胁迫程度的加强,出现先升高后降低的趋势;渗透调节物质脯氨酸及可溶性糖含量一直升高,处理组D3S3(重度干旱20%~25%相对含水量、重度盐胁迫600 mmol/L NaCl)根和叶中含量均最高;总黄酮含量呈现先升高后降低的趋势,根和地上部分中处理组D1S2(轻度干旱55%~60%相对含水量、中度盐胁迫400 mmol/L NaCl)总黄酮含量均达到最高,分别较对照提高了18.9%和72.1%。结论:蒙古黄芪可通过调节抗氧化酶类活性和渗透调节物质含量来应对盐旱的损伤,土壤相对含水量55%~60%、400 mmol/L NaCl交叉胁迫处理植株总黄酮积累量最多,且其生物量较高,为最适宜的水盐浓度组合,该处理条件有利于黄芪药材的优质高产栽培。

Objective:To explore the effect of double factors of salt and drought on the growth,physiological characteristics and the accumulation of total flavonoids in Astragalus membranaceus var.mongholicus,in order to guide its standardized planting.Methods:With the annual Astragalus membranaceus var.mongholicus as test materials,the effects of sixteen levels of salt and drought stress on growth,antioxidant enzymes(SOD,POD,CAT)activities,osmotic regulators(proline,soluble sugar)contents and total flavonoids accumulation of seedlings were studied.Results:After salt-drought stress,the above ground and underground biomass decreased.Antioxidant enzymes activities increased first and then decreased with the enhance of the degree of stress.The contents of proline and soluble sugar in osmotic regulatory substance increased all the time.In the treatment group D3S3(severe drought,20%~25%relative water content,severe salt stress,600 mmol/L NaCl),the contents in root and leaf were all the highest.The content of total flavonoids increased first and then decreased.The content of total flavonoids in D1S2(Light drought:55%~60%relative water content;moderate salt stress:400 mmol/L NaCl)in root and aboveground parts all reached the maximum,increasing by 18.9%and 72.1%,respectively,compared with the control group.Conclusion:Astragalus membranaceus var.mongholicus can deal with the damage of salt and drought by regulating the activities of antioxidant enzymes and the contents of osmotic adjustment substances.The total flavonoid accumulation in the plants under cross stress with soil relative water content of 55%~60%and 400 mmol/L NaCl is the most abundant and the biomass is higher,which is the best suitable water and salt concentration.The treatment group is beneficial for the good quality and high yield cultivation of Astragalus membranaceus var.mongholicus.