Varsamis Georgios, Adamidis George C, Merou Theodora, Takos Ioannis, Tseniklidou Katerina, Dimitrakopoulos Panayiotis G, Papageorgiou Aristotelis C
Department of Forest and Natural Environment Sciences, International Hellenic University, 66100 Drama, Greece.
Section of Plant Biology, Department of Biology, University of Patras, Rio, 26504 Patras, Greece.
Biology (Basel). 2022 Feb 14;11(2):306. doi: 10.3390/biology11020306.
Seasonality, rather than annual precipitation levels, is expected to affect the adaptive responses of plant populations under future climate change. To estimate adaptive traits' variation, we conducted a common garden experiment with two beech populations from contrasting climatic origins (Evros with longer drought intervals during summer and higher precipitation seasonality, and Drama representing a more temperate ecosystem). We simulated two different watering treatments (frequent vs. non-frequent) on beech seedlings, according to predicted monthly precipitation levels expected to prevail in 2050 by the CSIRO MK3.6 SRESA1B model, considering as reference area a natural beech stand in Mt. Rodopi, Greece. A series of morphological and stem anatomical traits were measured. Seedling survival was greater for the Evros population compared to that of Drama under non-frequent watering, while no difference in survival was detected under frequent watering. Leaf morphological traits were not generally affected by watering frequency except for leaf circularity, which was found to be lower under non-frequent watering for both populations. Stomata density in leaves was found to be higher in the Evros population and lower in the Drama population under non-frequent watering than frequent. Stem anatomical traits were higher under non-frequent watering for Evros but lower for the Drama population. Multivariate analyses clearly discriminated populations under non-frequent rather than frequent watering, indicating genetic adaptation to the population's environment of origin.
在未来气候变化下，预计影响植物种群适应性反应的将是季节性，而非年降水量水平。为了估计适应性性状的变异，我们对来自不同气候起源地的两个山毛榉种群进行了一项共同园圃实验（埃夫罗斯地区夏季干旱间隔较长且降水季节性较强，德拉马地区代表一个更温和的生态系统）。根据CSIRO MK3.6 SRESA1B模型预测的2050年将普遍出现的月降水量水平，我们对山毛榉幼苗模拟了两种不同的浇水处理方式（频繁浇水与不频繁浇水），并将希腊罗多彼山的一片天然山毛榉林作为参考区域。我们测量了一系列形态学和茎解剖学性状。在不频繁浇水的情况下，埃夫罗斯种群的幼苗存活率高于德拉马种群，而在频繁浇水的情况下，未检测到存活率的差异。除了叶圆度外，叶片形态性状一般不受浇水频率的影响，两个种群在不频繁浇水时叶圆度均较低。在不频繁浇水时，埃夫罗斯种群叶片的气孔密度较高，德拉马种群的气孔密度较低。在不频繁浇水时，埃夫罗斯种群的茎解剖学性状较高，而德拉马种群的则较低。多变量分析清楚地区分了不频繁浇水而非频繁浇水情况下的种群，表明存在对种群原生环境的遗传适应。
