Yan Xing-fu, Wang Jian-li, Zhou Li-biao
College of Biological Science and Engineering, Beifang University for Nationalities, Yinchuan 750021, China.
Ying Yong Sheng Tai Xue Bao. 2011 Jul;22(7):1682-8.
This paper studied the effects of different shading (55.4%, 18.9%, 5.5%, 2.2%, 0.5% , and 0.3% natural sunlight) on the seed germination and seedling growth of Quercus liaotungensis. The seed germination rate and germination index were the highest (72.5% and 0.22, respectively) at 55.4% natural sunlight, declined with decreasing light intensity, and were the lowest (42.5% and 0.11, respectively) at 0.3% natural sunlight. Strong light had definite delaying effect on the germination. The index of germination vigor increased with decreasing light intensity, being the maximum at 0.5% natural sunlight. The delay of seed germination under strong light could be the selective tradeoff on varied seed fates. Strong light benefited the basal stem diameter and root system growth and dry mass accumulation of Q. liaotunensis seedling, but resulted in the minimum seedlings height (6.06 cm). Greater morphological plasticity was observed for the seedlings under different shading, which lent support to the higher adaptability of the seedlings to light environment. For example, the specific leaf area, specific shoot length, specific root length, and chlorophyll b and total chlorophyll contents were the maximum at 0.5% natural sunlight, being 142.57 cm2 x g(-1), 156.86 cm x g(-1), 271.87 cm x g(-1), 0.07 g x cm(-2), and 0.24 g x cm(-2), respectively, and the minimum at 55.4% natural sunlight, being 44.89 cm2 x g(-1), 52.84 cm x g(-1), 101.98 cm x g(-1), 0.04 g x cm(-2), and 0.15 g x cm(-2), respectively. The variation of the root/shoot ratio of Q. liaotungensis seedlings under different shading could be the effects of the combination of light intensity and water availability.
本文研究了不同遮荫处理（55.4%、18.9%、5.5%、2.2%、0.5%和0.3%自然光照）对辽东栎种子萌发和幼苗生长的影响。在55.4%自然光照下，种子发芽率和发芽指数最高（分别为72.5%和0.22），随光照强度降低而下降，在0.3%自然光照下最低（分别为42.5%和0.11）。强光对种子萌发有一定的延迟作用。发芽活力指数随光照强度降低而增加，在0.5%自然光照下最大。强光下种子萌发延迟可能是对不同种子命运的选择性权衡。强光有利于辽东栎幼苗的基茎直径、根系生长和干物质积累，但导致幼苗高度最小（6.06厘米）。不同遮荫处理下的幼苗表现出更大的形态可塑性，这支持了幼苗对光照环境具有较高的适应性。例如，比叶面积、比茎长、比根长、叶绿素b和总叶绿素含量在0.5%自然光照下最大，分别为142.57平方厘米·克⁻¹、156.86厘米·克⁻¹、271.87厘米·克⁻¹、0.07克·厘米⁻²和0.24克·厘米⁻²，在55.4%自然光照下最小，分别为44.89平方厘米·克⁻¹、52.84厘米·克⁻¹、101.98厘米·克⁻¹、0.04克·厘米⁻²和0.15克·厘米⁻²。不同遮荫处理下辽东栎幼苗根冠比的变化可能是光照强度和水分有效性共同作用的结果。
