论文部分内容阅读
常绿阔叶树苦槠(Castanopsis sclerophylla)是亚热带地带性顶极群落的建群种之一,在区域森林资源保护和可持续利用方面具有重要的地位。在该区域日益严重的酸雨胁迫下,研究其对于胁迫的生理生态响应具有重要的理论价值和实践意义。该文以苦槠幼苗为研究材料,研究了酸雨胁迫对苦槠幼苗光合生理的影响。结果表明:(1)短时间内,pH2.5处理下的幼苗叶绿素相对含量最低,且与pH5.6处理下的存在显著性差异(p<0.05);经过一段时间处理后,pH4.0处理下的叶绿素相对含量最高,表明低浓度的酸雨会促进叶绿素相对含量的增加。(2)2007年4月,光合速率(Pn)、PSⅡ最大光化学效率(Fv/Fm)和PSⅡ的潜在活性(Fv/F0)在不同酸雨浓度处理下基本无变化。随着酸雨处理时间的延长,pH2.5处理下的Pn、光饱和点、光补偿点和暗呼吸速率有显著降低,且与pH5.6处理下的存在显著性差异(p<0.05)。pH2.5处理组与pH5.6处理组之间的Fv/Fm和Fv/F0差异性逐渐减小。表观量子效率和气孔导度变化规律不明显。综合来说,酸雨处理前期,高浓度的酸雨胁迫对苦槠幼苗叶绿素相对含量、光合生理参数有显著影响,但随着酸雨处理时间的增加,酸雨胁迫对苦槠幼苗的影响逐渐减小,表明其对外界不良环境具有一定的抵御能力和适应能力。
Castanopsis sclerophylla is one of the constructive species in the subtropical zonal climax community and plays an important role in the conservation and sustainable use of forest resources in the region. Under the increasingly severe acid rain stress in the region, studying its physiological and ecological response to stress has important theoretical and practical significance. In this paper, the bitter pomfret seedlings as research materials, the acid rain stress on the photosynthesis of Sophora flavescens physiology. The results showed that: (1) The relative content of chlorophyll in seedlings under pH 2.5 was the lowest in a short time, and there was a significant difference (P <0.05) with pH 5.6. After a period of treatment, Under the highest relative content of chlorophyll, indicating that low concentrations of acid rain will promote the relative content of chlorophyll increased. (2) The photosynthetic rate (Pn), maximum photochemical efficiency of PSⅡ (Fv / Fm) and the potential activity of PSⅡ (Fv / F0) did not change under different acid rain concentrations in April 2007. With the prolongation of acid rain treatment, Pn, light saturation point, light compensation point and dark respiration rate decreased significantly under pH2.5 treatment, and there was a significant difference (p <0.05) with pH5.6 treatment. The differences of Fv / Fm and Fv / F0 between pH2.5 and pH5.6 groups decreased gradually. Apparent quantum efficiency and stomatal conductance change is not obvious. In summary, the acid rain stress had a significant effect on the relative content of chlorophyll and photosynthetic physiological parameters in the early stage of acid rain treatment. However, with the increase of the acid rain treatment time, the influence of acid rain stress on the bitterness seedling decreased It has a certain degree of resilience and adaptability to adverse environmental conditions.