Effects of Light Intensity on Phenotypic Plasticity and Survival Strategy of Dracaena cambodiana Seedlings

Abstract:

In order to understand the effect of light intensity on seedling growth of Dracaena cambodian, the changes in morphological, physiological and biomass allocation characteristics were studied under four kinds of light intensity, including 100%, 37.3%, 15.5%, and 4.2% nature sunlight. The results showed that there were significant differences in morphological, physiological and biomass allocation indexes among different light intensities. The PI (plasticity indices) of all indexes ranged from 0.08 to 0.86, in which PI of biomass was generally higher (0.67-0.86) than that of the others, indicating that the seedlings had better adaptability to illumination conditions by adjusting the allocation of biomass. With the decrease of light intensity, the specific leaf area (SLA) and leaf area to root mass ratio (LARM) significantly increased, which indicated that the seedling could increase the leaf area and the area of photosynthesis to effectively adjust biomass allocation. In conclusion, the seedling growth of D. cambodiana would be the best under 37.3% NS (L2). Because the existing habitat of D. cambodiana was damaged, and the seedlings lacked shading, it was unfavorable to the growth of seedling root system during the dry season. So, this may be one of important reasons for the failure of the natural regeneration of D. cambodiana.

Key words:Dracaena cambodiana;Light intensity;Seedling growth;Biomass allocation;Phenotypic plasticity