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研究NaCl胁迫对夏枯草幼苗抗氧化能力与光合特性的影响,为夏枯草栽培管理、抗盐育种提供理论依据。以夏枯草幼苗为材料,采用营养液培养的方法研究不同浓度NaCl(0、20、40、60、80mmol/L)胁迫对夏枯草幼苗抗氧化酶、渗透调节物质、叶绿素、光合特性的影响。结果表明,随着盐胁迫浓度的升高,夏枯草叶片的超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、可溶性蛋白含量呈先上升后下降的趋势;过氧化物酶(POD)、可溶性糖含量、丙二醛(MDA)含量与电导率呈不断升高的趋势;叶绿素a和b、叶绿素a/b、类胡萝卜素及总叶绿素均呈逐渐下降的趋势;净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)均表现下降的趋势,胞间二氧化碳浓度(Ci)则表现为先下降后上升的趋势,而气孔限制值(Ls)表现为先升高后降低的趋势。在20~60mmol/L NaCl处理下,夏枯草叶片光合速率的下降主要是由气孔限制引起的,在80mmol/L NaCl处理下叶片光合速率的下降则主要是由非气孔限制引起的。NaCl胁迫下,夏枯草通过提高抗氧化酶的活性、渗透调节物质的含量来保护光合机构,从而提高夏枯草幼苗对盐胁迫的适应性。
The effects of NaCl stress on antioxidant capacity and photosynthetic characteristics of Prunella vulgaris seedlings were studied to provide a theoretical basis for Prunella vulgaris cultivation management and salt-resistant breeding. Prunella vulgaris seedlings were used as materials to study the effects of different concentrations of NaCl (0, 20, 40, 60 and 80 mmol / L) on the activities of antioxidant enzymes, osmotic adjustment substances, chlorophyll and photosynthesis of Prunella vulgaris seedlings. The results showed that the content of superoxide dismutase (SOD), ascorbate peroxidase (APX) and soluble protein in Prunella vulgaris leaves increased first and then decreased with the increase of salt stress concentration. The activity of peroxidase POD, soluble sugar content, malondialdehyde (MDA) content and electrical conductivity showed a rising trend. Chlorophyll a and b, chlorophyll a / b, carotenoids and total chlorophyll showed a gradual decline; net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) all showed a downward trend, and intercellular carbon dioxide concentration (Ci) showed a trend of first decreasing and then increasing while stomatal limitation value (Ls) High and then reduce the trend. Under 20 ~ 60mmol / L NaCl treatment, the decrease of photosynthetic rate of Prunella vulgaris leaves was mainly caused by the stomatal limitation. The decrease of photosynthetic rate under 80mmol / L NaCl treatment was mainly caused by the non-stomatal limitation. Under the stress of NaCl, Prunella vulgaris protected the photosynthetic mechanism by increasing the activity of antioxidant enzymes and osmotic adjusting substances, and thus the adaptation of Prunella vulgaris seedlings to salt stress was improved.