不同光环境下胡桃楸幼苗的形态可塑性及其响应研究

为了探求不同光环境对胡桃楸幼苗生长的影响，对全光照（100%光照）、中光照（60%光照）、低光照（30%光照）3种光环境下胡桃楸幼苗的生长、形态特征、生物量分配和水分特征开展研究。结果表明：胡桃楸幼苗的形态在不同光环境下存在明显的可塑性变化，生物量分配和水分特征均表现出不同程度的差异。低光照条件下，胡桃楸幼苗生长快，株高、地径分别为全光照的1.14、1.18倍；冠幅大，是全光照的1.40倍；叶片宽大，叶长和叶宽分别是全光照的1.25和1.36倍；分枝数明显少于全光照。3种光环境下胡桃楸幼苗地上部分生物量存在显著差异，地下部分差异不显著。叶片相对含水量随着光照的降低呈现逐渐增加的趋势；全光照条件下叶片饱和持水量与叶片干鲜比明显大于遮阴条件；3种光照条件下叶绿素含量差异显著。胡桃楸幼苗为适应不同光环境，在形态和生理方面都做出适应性调整，适当的遮阴处理有利于胡桃楸幼苗生长。

Phenotypic Plasticity and Respond of Juglans mandshurica Seedling under Different Light Environments

We studied the growth of the seedling, morphological characteristics, biomass allocation and water feature of Juglans mandshurica seedling under different light environments(100%, 60%, 30% light). The architectural model was modified plastically in response to different light conditions, the biomass allocation and water feature has some differences. Under low light conditions, J.mandshurica seedling growth fast, plant height, ground diameter were 1.14 times and 1.18 times. The canopy was big, which were 1.4 times. Leaf is broad, leaf length and leaf width were 1.25 and 1.36 times and branch number less than total light. The biomass of above ground uner three kinds of light environment was with significant differences, but underground part of the difference is not significant. Leaf relative water content was increased with the decrease of light gradually trend, which were under the condition of blade was bigger than the saturated water capacity and leaf dry fresh under shade conditions. There was significant difference in chlorophyll content under three light conditions. J.mandshurica adapted to different light environment in morphology and physiology, and the appropriate shade treatment was beneficial to the growth of J.mandshurica seedling.