Lyons Tom M, Barnes Jeremy D, Davison Alan W
The Air Pollution Laboratory, Department of Agricultural and Environmental Science, Ridley Building, The University, Newcastle Upon Tyne, NE1 7RU, UK.
New Phytol. 1997 Jul;136(3):503-510. doi: 10.1046/j.1469-8137.1997.00773.x.
The relative ozone resistance of 20 European and two American populations of Plant ago major was examined, and relationships with climatic factors at the source of the plant material were explored using data provided by participants in the ICP-Crops initiative (International Co-operative Programme to Investigate the Effects of Air Pollutants and Other Stresses on Agricultural and Semi-Natural Vegetation). Plants grown from seed were exposed to either charcoal/Purafil® filtered air (CF < 5 nmol mol O ) or CF + ozone (70 nmol mol O 7 h d ) over a 2-wk period in controlled environment chambers, and effects on mean plant relative growth rate (R) and allometric root/shoot growth (K) determined. Ozone resistance (R%) was calculated from (R /R ) × 100. Populations exhibited contrasting sensitivities to ozone, without the development of typical visible symptoms of injury. A positive relationship was found between relative ozone resistance and descriptors of the ozone-climate at the site of seed collection for the year of, and the 2 yr before, seed collection. The best predictors of inherent ozone resistance were shown to be cumulative ozone exposure indices calculated according to current United Nations Economic Commission for Europe (UN-ECE) critical level guidelines for the pollutant (i.e. the accumulated hourly average ozone exposure over a threshold level of 40 nmol mol (AOT40) or 30 nmol mol (AOT30) calculated during daylight hours for the consecutive 3-month period of the year experiencing the highest ozone concentrations). No relationships were found between ozone resistance and climatic factors (temperature, precipitation, sunshine hours, humidity) or the concentrations of other air pollutants (SO , NO , NO). These findings support the view that current ambient levels of ozone in many regions of Europe are high enough to promote evolution of resistance to the pollutant in native plant populations. The significance of these findings to the debate over the establishment of separate critical levels for the protection of natural and semi-natural vegetation is discussed.
研究了20个欧洲种群和2个美国种群的大车前（Plantago major）对臭氧的相对抗性，并利用国际作物污染影响合作计划（ICP-Crops，旨在调查空气污染物和其他胁迫对农业和半自然植被影响的国际合作项目）参与者提供的数据，探索了其与植物材料来源地气候因素之间的关系。将种子培育出的植株在可控环境舱中暴露于木炭/ Purafil® 过滤空气（CF < 5 nmol mol⁻¹ O₃）或CF + 臭氧（70 nmol mol⁻¹ O₃，每天7小时）环境下2周，测定其对植株平均相对生长速率（R）和异速根/茎生长（K）的影响。臭氧抗性（R%）通过（R₀ / R）× 100计算得出。各种群对臭氧的敏感性存在差异，且未出现典型的可见伤害症状。研究发现，种子采集当年及采集前两年，相对臭氧抗性与种子采集地的臭氧 - 气候描述指标之间存在正相关关系。结果表明，根据当前联合国欧洲经济委员会（UN-ECE）针对该污染物的临界水平指南计算的累积臭氧暴露指数，是固有臭氧抗性的最佳预测指标（即一年中臭氧浓度最高的连续3个月白天时段，超过40 nmol mol⁻¹（AOT40）或30 nmol mol⁻¹（AOT30）阈值水平的每小时平均臭氧暴露累积量）。未发现臭氧抗性与气候因素（温度、降水量、日照时数、湿度）或其他空气污染物（SO₂、NOₓ、NO）浓度之间存在相关性。这些发现支持了以下观点：欧洲许多地区当前的臭氧环境水平足以促进本地植物种群对该污染物抗性的进化。文中还讨论了这些发现对于围绕设立单独临界水平以保护自然和半自然植被的争论的意义。
