Environmental effects on leaf morphology traits in the populus euphratica Oliv. provenances of Iran

Abstract

We studied the variation in leaf morphological traits for 7 habitats of Populus euphratica Oliv. in natural form as well as transplanted to an experimental station in Karadj- Iran. In this study, 28 even-aged, mature P. euphratica trees and 24 leaf samples were randomly collected from each habitat (6 leaves for each tree). Then a set of macro- and micro-morphological characteristics were measured on the samples. There was a plastic morphological response to the environment for each provenance. All morphological characters except maximum leaf width (MLW), ratio of petiole length to leaf length (PL: LL) and the distance between the middle of maximum leaf width and leaf blade (DLL) varied significantly among provenances in both natural and field conditions. Stomata density and stomata size were plastic characters, since the stomata density increased in warm habitats while stomata size decreased. In addition, we observed significant differences in size and density of stomata for natural and field-transplanted provenances. Correlation analysis between environmental factors and leaf morphological traits indicated a significant relationship. Furthermore, Principal component analysis (PCA) on all morphological traits on provenances showed that morphological range of the provenances decreases when growing in the experimental field compared to their natural habitat. Eventually, we found a weak significant correlation between geographical and morphological distances.

Keywords

• Populus euphratica
• provenance
• leaf morphology
• environmental factor
• geographic distance