Effect of light intensities on the photosynthetic characteristics of Abies holophylla seedlings from different provenances

Abstract

The photosynthetic characteristics of Abies holophylla seedlings from six provenances under four artificial light intensities in a greenhouse (full light, 75.08%, 55.42%, and 30.38% of full light) were studied to explore the underlying genetic differences in foliar photosynthesis. Varying light intensities significantly affected the foliar photosynthetic parameters of A. holophylla seedlings from six provenances. As the light intensity dropped, the foliar CO2 assimilation capacity of A. holophylla seedlings sharply decreased, and the foliar light utilization capacity significantly increased. Analysis of genetic variation showed highly significant differences in terms of CO2 assimilation capacity, light utilization capacity, and respiration depletion of A. holophylla seedlings among different provenances under different light intensities. The variations were mainly controlled by the genetic factors of the provenance itself. The obtained results revealed that different sensitivities of A. holophylla seedlings from different provenances in response to changed light intensities elicited significant differences in foliar photosynthesis among different provenances. The relationships between sensitivities and annual temperature difference, mean temperature in January, and mean annual evaporation of provenance were found to be the most closely related, which indicated that temperature range and effective precipitation of provenance were the main factors that affected photosynthetic plasticity of A. holophylla seedlings.