光照对辽东栎种子萌发和幼苗生长的影响

研究了不同光照梯度[55.4%自然全光照(natural sunlight,NS)、18.9%NS、5.5%NS、2.2%NS、0.5%NS和0.3%NS]对辽东栎种子萌发和幼苗生长的影响.结果表明:辽东栎种子的萌发率和萌发指数在55.4%NS处理达到最大,分别为72.5%和0.22,然后随着光照减弱而逐渐减小,在0.3%NS处理下最小,分别为42.5%和0.11;强光照对种子萌发进程有一定的延迟作用,萌发活力指数随着光照的减弱而增大(0.5%NS处理最大);强光下种子萌发的延迟可能是其对多种命运的权衡性选择.强光照有利于辽东栎幼苗基径和根系生长,以及幼苗干物质的积累,但株高最小(6.06 cm);不同光强处理的辽东栎幼苗具有较大的形态学可塑性,其幼苗阶段对光环境的适应性较强,0.5%NS处理的幼苗比叶面积、比枝长、比根长、叶片叶绿素b含量及叶绿素总量均最大,分别为142.57 cm2.g-1、156.86 cm.g-1、271.87 cm.g-1、0.07 g.cm-2和0.24 g.cm-2,55.4%NS处理下最小,分别为44.89 cm2.g-1、52.84 cm.g-1、101.98 cm.g-1、...

Effects of light intensity on Quercus liaotungensis seed germination and seedling growth

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 ...