攀援植物绞股蓝幼苗对光照强度的形态和生长反应

 利用遮阳网产生光照强度梯度，以研究攀援植物绞股蓝(Gynostemma pentaphyllum)幼苗对光梯度的形态和生长反应。结果表明：1)相对生长速率、净同化速率和总生物量随光照强度减弱而降低，总叶面积、比茎长、株高、分枝角度、叶面积率和比叶面积却增加；2)株高生长与相对生长速率成负相关；3)幼苗生物量分配对光梯度的反应不敏感。这些结果意味着绞股蓝幼苗的形态和生长反应对不同光环境具有可塑性，比茎长和株高随光照减弱而增加有利于绞股蓝幼苗“寻找”到外界支持物。

MORPHOLOGICAL AND GROWTH RESPONSES OF THE CLIMBING PLANT, GYNOSTEMMA PENTAPHYLLUM SEEDLINGS TO VARYING LIGHT INTENSITY

Variation in morphology and growth of seedlings of the climbing plant, Gynostemma pentaphyllum was examined in response to a light intensity gradient artificially created using plastic shade web. This revealed that G. pentaphyllum seedlings show a high level of plasticity in both morphology and growth in response to varying light environments: 1) relative growth rate, net assimilation rate, and total biomass decreased with decreasing light resource, while total leaf area, specific stem length, shoot height, branching angle, leaf area ratio, and specific leaf area increased with decreasing light; 2) relative growth rate declined with increasing plant size; 3) variation in light had no significant effects on biomass allocation. The increased specific stem length and shoot height observed across decreasing light intensities may enhance the likelihood that G. pentaphyllum seedlings will encounter external supports.