紫外辐射对菹草成株表型可塑性及石芽的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 紫外辐射对菹草成株表型可塑性及石芽的影响 DOI: 10.5846/stxb201401160120 作者: 作者单位: 南京信息工程大学应用气象学院,南京信息工程大学环境科学与工程学院,南京信息工程大学大气物理学院,江苏省大气环境监测与污染控制高技术重点实验室;南京信息工程大学环境科学与工程学院,南京信息工程大学应用气象学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金(41105113,51109109);江苏省环境演变与生态建设重点实验室开放基金资助项目;南京信息工程大学本科生优秀毕业论文(设计)支持计划项目 Effect of ultraviolet radiation on phenotypic plasticity and turion of Potamogeton crispus Author: Affiliation: School of Applied Meteorology, Nanjing University of Information Science & Technology,School of Environmental Science and Engineering,Nanjing University of Information Science Technology,School of Atmospheric Physics, Nanjing University of Information Science & Technology,Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control;School of Environmental Science and Engineering,Nanjing University of Information Science Technology,Nanjing University of Information Science Technology Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:菹草衰亡的原因一直是水体生态修复的研究热点,已有的研究认为强光照是促进菹草衰亡的关键因素,强光照中对动植物有害波段主要为UV-B波段,为此分别将菹草成株置于50、100、150、200 μW/cm2剂量的UV-B辐射下,每日持续辐射6h(9:00-15:00),对照组接受的UV-B剂量为0,仅接受UV-A和光合有效辐射,监测菹草生长、形态状况、石芽形成及萌发等指标。结果表明,高剂量UV-B辐射能促进菹草成株的衰亡进程,即使暴露在低剂量UV-B辐射条件下,植株仍然衰亡;植株株高、节间距、叶面积、单株鲜重都受到UV-B辐射的抑制,且随UV-B辐射剂量增加,各项指标明显下降;UV-B辐射对菹草成株形成的石芽数量无显著影响,但形成的石芽随辐射剂量增加变态率增高,长度增加,宽度减少,石芽重量减轻,下一个生长季萌发率降低,萌发出二苗的比率降低,萌发苗各项生长指标随辐射剂量增加逐渐降低。因此,春末夏初UV-B辐射增强可能是导致菹草大批衰亡的重要原因。 Abstract:Potamogeton crispus is important in purifying water and maintaining a healthy aquatic ecosystems such as shallow lakes. However, mass mortality occurs in P. crispus populations in the late spring and early summer, which possibly results in secondary pollution. Therefore, the causes of P. crispus mass mortality have been a very important research topic in the field of water ecological restoration. The UV-B band in the strong light is generally recognized to damage plants and animals and even to penetrate into the water column and harm aquatic organisms. Some researchers have reported that intense light is the key factor in P. crispus decline. We carried out a series of experiments to find the effect of UV-B radiation in the strong light on P. crispus decline. In this study, adult plants of P. crispus are exposed to UV-B radiation in different doses (50 μW/cm2, 100 μW/cm2, 150 μW/cm2, and 200 μW/cm2) for 6 hours (9:00-15:00) every day, and the control group was exposed only to UV-A radiation and photosynthetically active radiation (PAR). Plant growth, morphological changes (plant height, internodal length, leaf area and fresh weight), turion formation (number, weight, and morphology of turion) and the germination indexes of turion were monitored. The results show that UV-B radiation can accelerate plant decline. When the exposure dose is in excess of 150 μW/cm2, the plants decline and fall within 31 days, while a few plants in the other treatment groups still grow. The tops of the plants are damaged more when they receive higher doses of UV-B radiation, so that plant height declines persistently with UV-B radiation, the internodal length is shortened by UV-B radiation, the leaf area shrinks, and the average fresh weight per plant decreases; whereas the plant height and internodal length of the control group increase till the 24th day, the leaf area also increases till the 16th day, and the average fresh weight per plant decreases gradually with increasing radiation doses. UV-B radiation had no effect on turion quantity in both the treatment and control groups, but the metamorphosis ratio of turion increases with the increasing radiation dose. When the exposure dose of UV-B radiation increases, the turion length increases, whereas the turion width and weight are reduced, the germination rate from the next growing season is reduced. The ratio of two seedlings that germinated from these turions decreases and the seedling growth indexes (germination rate, plant height, leaf number, leaf length, leaf width, leaf area, and so on) decrease and are significantly reduced especially when the exposure dose is in excess of 150 μW/cm2. The results indicate that UV-B radiation may be an important factor leading to mass mortality of P. crispus in late spring and early summer. Accordingly, we deduce that the sharply enhanced ultraviolet radiation on the land surface in the late spring and early summer leads to mass mortality of the natural P. crispus population. However, further research is necessary to study whether UV-B radiation acts synergistically with other environmental factors on the decline of P. crispus. 参考文献 相似文献 引证文献