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该文主要探讨水培条件下,不同浓度锶胁迫(~(88)Sr~(2+),0、1、3、5、8 mmol/L)对垂柳(Salix babylonica)光合作用能力的影响,进而为利用木本植物生态治理锶污染奠定研究基础。试验结果表明:随着~(88)Sr~(2+)浓度的升高,荧光参数PSII的实际光能转换效率(Y(Ⅱ))、最大光能转换效率(F_v/F_m)、光化学淬灭系数(qP)、均随着浓度的升高而呈现出先升高后而下降,在1 mmol/L时达到最大;非光化学猝灭系数(NPQ)在8 mmol/L处理时显著升高,表明高浓度~(88)Sr~(2+)处理,叶片PSII光能转换效率虽然显著下降,但通过增加热耗散对光合器官进行一定程度保护;气体交换参数蒸腾速率(E)、气孔导度(Gs)和光合速率(A)均随着~(88)Sr~(2+)的升高也呈现出先升后降的趋势,均在1 mmol/L达到最大;而胞间CO_2(Ci)浓度则逐渐升高,说明影响光合速率的主要因素是非气孔因素占主导;此外,叶片叶绿素a、b和a/b也呈现出先升后降的趋势,且在1 mmol/L时叶片叶绿素含量最高。研究结果揭示低浓度~(88)Sr~(2+)胁迫处理能够通过增强垂柳叶片光能利用、气体交换能力和叶绿素合成来促进其光合作用能力,但高浓度的胁迫会对植物的光合能力带来明显的损伤进而影响其正常的生长发育。
In this paper, the effects of strontium stress (~ (88) Sr 2+, 0, 1, 3, 5 and 8 mmol / L) on the photosynthetic capacity of Salix babylonica under hydroponics were investigated. Which laid the foundation for making use of the ecological control of strontium pollution in woody plants. The results showed that the actual conversion efficiency (Y (Ⅱ)), the maximum conversion efficiency (F_v / F_m), the photochemical quenching The extinction coefficient (qP) increased firstly and then decreased with increasing concentration, reaching the maximum at 1 mmol / L. The NPQ increased significantly at 8 mmol / L, The results showed that the photosynthetic organs were protected to some extent by increasing the heat dissipation while the treatment with high concentration of 88 Sr 2 + had a significant reduction in the photosynthetic rate of PSII. The gas exchange parameters of transpiration rate (E), stomatal conductance (Gs) and photosynthetic rate (A) both increased firstly and then decreased with the increasing of (88) Sr 2+, and both reached the maximum at 1 mmol / L. The intercellular CO_2 ) Concentration gradually increased, indicating that the main factors affecting the photosynthetic rate are dominated by non-stomatal factors; In addition, leaf chlorophyll a, b and a / b also showed a trend of first rising and then falling, and 1 mmol / L leaf chlorophyll content highest. The results showed that low concentrations of ~ (88) Sr ~ (2+) stress could promote the photosynthesis ability of weeping willow leaves by increasing the light energy utilization, gas exchange ability and chlorophyll synthesis. However, the high photosynthetic stress Bring obvious damage and then affect their normal growth and development.