摘要
为了解弱光环境对高地省藤幼苗生长与光合作用的影响,在实验室条件下用日光灯照射,遮阳网遮荫,设置5种光强环境(L1:3 200 lx,L2:1 954 lx,L3:1 255 lx,L4:650 lx,L5:350 lx)处理,分析高地省藤幼苗形态生长、光合特性的变化。结果表明:光强处理L2下的株高、叶长、地径、鲜质量显著高于L3、L4、L5,但地径、鲜质量显著低于L1;随着光照强度的下降,幼苗的株高和叶片长度增长量呈先升高后降低的变化趋势,而地径和鲜质量增长量呈持续降低趋势;幼苗叶绿素a、b及叶绿素(a+b)的含量在光强L1、L2时较大,随光强减弱不断减少,叶绿素a/b则呈不断减小的趋势。随光强减弱,幼苗的最大光合速率、表观量子效率、呼吸速率、光补偿点、光饱和点均有不同程度的降低,L1、L2处理下的5个光合生理参数均高于L3、L4、L5。高地省藤幼苗生长期间可适度遮荫,1 954 lx是高地省藤幼苗所能忍耐光胁迫的下限值。
The morphological growth and photosynthetic characters of Calamus nambariensis seedlings in re- sponse to different light intensities were studied in the laboratory by means of applying shading-nets and artificial daylight lamps with five light intensity gradients （L1：3 200 Ix, L2：1 954 Ix, 1.3：1 255 Ix, L4：650 Ix, L5：350 Ix） to understand the effects of low light environment on the growth and photosynthesis of the plant species. The results indicated that the plant height, leaf length, basal diameter and the fresh biomass of the seedlings under L2 light in- tensity treatment were significantly higher than those of L3, L4 and Ls, treatments, but the basal diameter and fresh biomass indexes were lower than those of obtained under L1. With the decline in light intensity, the growth of height and leaf length increased at the initial stage and then decreased, while the of basal diameter and fresh biomass kept declining. The contents of chlorophyll a, b and a ＋ b were high under L1 and Lz treatments, then the Chl afb content dropped as the light intensity decreased. The maximum net photosynthetic rate, apparent quantum efficiency, dark respiration rate, light compensation point and light saturation point indexes dropped to different ex- tent along with the decrease of light intensity, treatments were all higher than those of under nambariensis could tolerate a certain degree of and the above L3, L4 and L5 five photosynthetic indexes under the L1 and L2 light light treatments. Comprehensively speaking, Calamus shading at its seedling stage. The experiment showed that 1 954 lx oflight intensity was the lowest limit of light stress for Calamus nambariensis seedlings.
出处
《西南林业大学学报（自然科学）》
CAS
2013年第1期16-21,共6页
Journal of Southwest Forestry University：Natural Sciences
基金
国家林业局948项目(2011-4-48)资助
关键词
高地省藤
实生苗
弱光
形态生长
光合作用
Calamus nambariensis
seedlings
low light
morphological growth
photosynthesis
