人工模拟增雨对油蒿种子形态性状和比叶面积的影响

【目的】研究油蒿的种子大小和比叶面积对不同增雨处理的响应,探明两者之间的关系,以期揭示油蒿植物功能性状对降水量变化的响应机制和演变趋势。【方法】根据内蒙古磴口县多年平均降水量,在植物生长季5—9月设计4个增雨梯度(25%,50%,75%和100%),对天然油蒿灌丛进行增雨试验,利用Winseedle种子和针叶图象分析软件系统,对比了油蒿种子表型形态特征和比叶面积对降水增多的响应,同时通过相关分析研究了油蒿种子大小与比叶面积的关系。【结果】不同增雨量对油蒿种子长度、宽度、体积、表面积及千粒重均有显著影响,在100%增雨处理下种子各性状指标达到最小值,其中种子宽度、体积、表面积与增雨量呈极显著负相关(P<0.01)。种子长度和千粒重与增雨量呈显著负相关(P<0.05),种子长宽比与增雨量的相关性不显著(P>0.05)。不同增雨量对油蒿比叶面积的影响差异性显著(P<0.05),且随着雨量的增加,比叶面积不断增大。种子大小与比叶面积呈负相关关系,但均未达到显著水平(P>0.05)。【结论】降水增加后油蒿种子会先增加后减小来适应环境变化,通过油蒿种子、比叶面积两大植物功能性状组合对增雨量处理响应的研究体现了荒漠植物应对未来气候变化的生存策略和适应机制。

Effects of artificial simulated precipitation on seed morphology and specific leaf area of Artemisia ordosica

【Objective】The response of the seed size and specific leaf area of Artemisia oleracea to different precipitation treatments was studied to explore their relationship,so as to reveal the response mechanism and evolution trends of plant functional traits of Artemisia oleracea to rainfall changes.【Method】Based on the annual average precipitation of Dengkou county,the artificial simulation of precipitation experiment with four rain enhancement gradient(25%,50%,75%and 100%)was conducted to Artemisia ordosica shrub during the growing season(from May to September).In this study,the response of the phenotypic morphological features of A.ordosica seed and specific leaf area to the precipitation increase was compared by Winseedle seed and needle photo analysis system.Meanwhile,the relationship between seed size and specific leaf area was studied by correlation analysis.【Result】The results show that there are effects of different precipitation on the length,width,volume,surface area and thousand seed mass of A.ordosica.The precipitation enhancement processing under 100%of A.ordosica.seeds traits reach the minimum value.The width,volume and surface area are very significant negatively correlated with rainfall(P<0.01).The length and thousand seed mass are significantly negatively correlated with rainfall(P<0.05).There is no significant difference between length width ratio and rainfall(P>0.05).The influence of precipitation enhancement than specific leaf area difference significant(P<0.05).With the increase of rainfall,the specific leaf area increases continuously.Seed size and specific leaf area are negative correlation,but they have no significant difference(P>0.05).【Conclusion】When rainfall increases,seeds first increase and then decrease to adapt to environmental changes.The study on the response of the functional traits combination of seed and specific leaf area to the precipitation treatment reflects the survival strategy and adaptation mechanism of desert plants to the future climate change.