不同生长期旱后复水对侧柏幼苗生物量的影响

Effect of Re-watering after Drought on Biomass of Platycladus orientalis Seedlings in Different Growth Stages

为探讨不同生长期旱后复水对侧柏(Platycladus orientalis)幼苗生长的补偿效应,采用盆栽控水方法研究了生长前期、生长中期和生长末期旱后复水对侧柏幼苗单株生物量、地下部分生物量和根冠比的影响。结果表明,在不同水分胁迫程度下,生长前期单株生物量、地下部分生物量和根冠比的变化在复水之后无明显规律。生长中期侧柏的单株生物量随胁迫程度增大呈下降趋势;地下部分生物量和根冠比随胁迫程度的增大呈上升趋势。在不同胁迫历时下,单株生物量在前期和中期出现了补偿效应,且在胁迫30d和胁迫45d之后,补偿效应最明显;地下部分生物量在生长前期复水之后出现了明显的补偿效应;根冠比在生长前期和中期复水之后随胁迫历时的增加呈下降趋势。生长末期未出现补偿效应。

In order to discuss the compensatory effect of re-watering after drought on biomass of Platycladus orientalis in different growth stages,apot experiment was conducted respectively in early growth stage,middle growth stage and last growth stage to study the effects of re-watering on individual biomass,underground biomass and root-shoot ratio in seedlings of P.orientalis.The results showed that at different levels of water stress,the changes of individual biomass,underground biomass and root-shoot ratio in early growth stage were irregular after re-watering.In middle growth stage the individual biomass decreased with the increase of water stress levels;the underground biomass and root-shoot ratio showed an upward trend with the increase of water stress levels.Under different stress durations,individual biomass had compensatory effects in the early and middle growth stages,and an obvious compensatory effect occurred after 30d and 45d;underground biomass in early growth stage had an obvious compensatory effect after re-watering;root-shoot ratio at early and middle growth stages presented a downward trend after rewatering with the increase of stress duration.The last growth stage did not have compensatory effect.