温度和水分对中华羊茅幼苗生长的影响

摘要

本试验采用室内盆栽法对不同温度和水分互作条件下中华羊茅幼苗生长的形态特性进行了研究，通过设定4个土壤水分梯度（80％，65％，50％和35％FWC，FWC 为田间最大持水量）和3 个生长温度（15，20和25℃）来模拟自然生长条件来探究适宜中华羊茅幼苗生长的温度和土壤水分条件。结果表明，中华羊茅在25℃、65％水分条件下的出苗率最高，且显著高于其他温度和水分处理（P ＜0．05），而对照和其他水分处理的幼苗株高在20℃条件下均显著高于15和25℃处理（P ＜0．05）；3种温度下中华羊茅幼苗的茎粗在65％水分条件下均达到最大，在35％水分条件下最小，且与其他水分处理差异显著（P ＜0．05）；在15和20℃条件下，中华羊茅幼苗的叶宽、组织含水量、株高胁迫指数和干物质胁迫指数均在65％水分条件下最大，在35％水分条件下最小，而在25℃条件下，其随着土壤水分含量的降低而逐渐减小，且在80％水分条件下达到最大；3种温度下中华羊茅幼苗的根冠比随着土壤水分含量的降低而逐渐增大，其在35％水分条件下最大，且显著大于对照和其他水分处理（P ＜0．05）；20℃条件下，中华羊茅幼苗的根长在35％水分条件下最大，而在15和25℃条件下，其根长在50％水分条件下最大，且均与对照和其他水分处理差异显著（P ＜0．05）。因此，由结果得出20℃温度和65％水分条件最适于中华羊茅幼苗的生长。%Morphological characteristics of Festuca sinensis seedling growth were studied using the inner potted method under different temperature and moisture conditions.In order to explore the appropriate conditions for seedling growth,natural growth conditions were simulated by setting four soil moisture contents (80%,65%, 50% and 35% field maximum water capacity,FWC)and three temperature levels (15,20 and 25 ℃).The re-sults showed that the emergence rate of F .sinensis was highest under the condition of 25 ℃ and 65% moisture content (P <0.05).The plant height of the control and other moisture treatments were significantly higher at 20 ℃ than the 15 and 25 ℃ treatments (P <0.05).Seedling stem diameter under the three temperature treat-ments all reached their highest scores under the 65% moisture content condition,while the lowest scores were recorded at 35% moisture content (P <0.05).At 15 and 20 ℃,blade width,plant tissue water content,plant height stress index and dry matter stress index were the largest at the 65% moisture condition and lowest at the 35% moisture condition.However,at 25 ℃ these factors decreased with the loss of soil moisture content,with the highest scores recorded at the 80% moisture condition.The root-shoot ratios of F .sinensis under the three temperature treatments increased with the loss of the soil moisture content,reaching maximum levels at 35%, significantly greater than the control and other moisture treatments (P <0.5 ).Under the 20 ℃ treatment, seedling root length was the largest at 35% moisture content,while under the 15 and 25 ℃ treatments it was largest at 50% moisture content and significantly greater than the control and other moisture treatments (P <0.05).Therefore,it is concluded that 20 ℃ temperature and 65% soil moisture content is the most suitable condition for the growth of F .sinensis seedlings.