Oksanen E, Amores G, Kokko H, Amores J M, Kärenlampi L
Department of Ecology and Environmental Science, University of Kuopio, POB 1627, 70211 Kuopio, Finland.
Tree Physiol. 2001 Oct;21(16):1171-81. doi: 10.1093/treephys/21.16.1171.
Saplings of six Finnish hybrid aspen (Populus tremuloides Michx. x P. tremula L.) clones were exposed to 0, 50, 100 and 150 ppb ozone (O3) for 32 days in a chamber experiment to determine differences in O3 sensitivity among genotypes. Based on the chamber experiment, three clones with intermediate sensitivity to O3 were selected for a free-air O3 enrichment experiment in which plants were exposed for 2 months to either ambient air (control) or air containing 1.3 x the ambient O3 concentration. We measured stem height and radial growth, number of leaves, dry mass and relative growth rate of leaves, stem and roots, visible leaf injuries, net photosynthesis and stomatal conductance of the clones. There was high clonal variation in susceptibility to O3 in the chamber experiment, indicated by foliar injuries and differential reductions in growth and net photosynthesis. In the free-air O3 enrichment experiment, ozone caused a shift in resource allocation toward stem height growth, thereby altering the shoot to root balance. In both experiments, low O3 concentrations tended to stimulate growth of most clones, whereas 100 and 150 ppb O3 in the chamber experiment impaired growth of most clones. However, growth of the most O3-tolerant clone was not significantly affected by any O3 treatment.
在一项室内实验中，将六个芬兰杂交白杨（颤杨×欧洲山杨）无性系的树苗暴露于0、50、100和150 ppb的臭氧（O₃）环境中32天，以确定不同基因型对O₃敏感性的差异。基于该室内实验，选择了三个对O₃具有中等敏感性的无性系进行开放式空气O₃浓度升高实验，在该实验中，植物被暴露于环境空气（对照）或含有1.3倍环境O₃浓度的空气中2个月。我们测量了这些无性系的茎高和径向生长、叶片数量、干质量以及叶片、茎和根的相对生长速率、可见叶片损伤、净光合作用和气孔导度。在室内实验中，通过叶片损伤以及生长和净光合作用的差异降低表明，对O₃的易感性存在高度的无性系变异。在开放式空气O₃浓度升高实验中，臭氧导致资源分配向茎高生长转移，从而改变了地上部分与地下部分的平衡。在两个实验中，低O₃浓度往往会刺激大多数无性系的生长，而在室内实验中，100和150 ppb的O₃会损害大多数无性系的生长。然而，最耐O₃的无性系的生长并未受到任何O₃处理的显著影响。
