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采用人工控制土壤水分试验,以80%田间持水量处理为对照,研究了3次干旱-复水处理对2年生杠柳幼苗叶片光合作用,根、茎、叶膜脂过氧化和抗氧化系统的影响.结果表明:在干旱条件下,杠柳叶片相对含水量和光合速率(Pn)显著降低,光合色素含量升高.干旱复水后,叶片相对含水量完全恢复,反映了杠柳较强的旱后修复能力;叶绿素含量和Pn均明显高于对照,表现出补偿效应,适度干旱诱导了杠柳的抗旱适应性.干旱胁迫使Pn下降,以气孔限制为主,但在中午发生了非气孔限制;幼叶、新茎和细根中的超氧阴离子产生速率升高,丙二醛含量则降低,说明这些幼嫩组织未受到氧化伤害.不同器官中SOD、CAT和POD活性及变化趋势不同,以细根的3种保护酶的反应最为灵敏,说明细根是杠柳适应干旱环境的重要器官.器官间的相互合作与协调使杠柳能有效地适应干湿交替的干旱环境.
Artificial soil moisture control was used to control the photosynthesis, the lipid peroxidation of root, stem and leaf and the antioxidant system in two - year - old birch seedlings with three treatments of 80% field water as control. The results showed that the relative water content and photosynthetic rate (Pn) and the photosynthetic pigment content of the leaves of Periploca sepium under drought stress were significantly increased.The relative water content of the leaves recovered completely after the rehydration, Drought tolerance ability, chlorophyll content and Pn were significantly higher than the control, showing a compensatory effect, moderate drought induced barbarium drought adaptability.Drought stress to Pn decreased to stomatal limitation, but at noon occurred in non-stomata The rate of production of superoxide anion in young leaves, new stems and fine roots increased and the content of malondialdehyde decreased, indicating that these young tissues were not damaged by oxidative stress.The activity and the change trend of SOD, CAT and POD in different organs were different , The most sensitive reaction of the three kinds of protective enzymes with fine roots showed that the fine roots were the important organs that the stems adapt to the drought environment.The mutual cooperation and coordination between the organs allowed the stems and leaves to effectively adapt to the dry and wet alternating dry environments.