Effect of site and provenance on the thickness of transfusion parenchyma of Douglas-fir needles

Variability of introduced tree species can be assessed through provenance tests. Their genetic and ecological adaptability can be confirmed by investigating the variability of anatomical traits, analyzed in this research study. The aim of the paper was to determine whether there are differences in the width of transfusion parenchyma of Douglas-fir needles in different provenance in different habitats in Serbia. In Serbia, 2 provenance tests of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), whose seed originated from North America, were established with the aim of testing the species. A 2-factor analysis of variance of the thickness of needle transfusion parenchyma was carried out in order to study the effects of the interactions between site-specific conditions of the locations where the provenance tests were set. The role of this parenchyma is to support conductivity of water and mineral matters from xylem bundles and organic matters from chlorenchyma to phloem bundles. The analysis of variance shows that there are statistically significant differences in the values obtained for the studied anatomical traits between the provenances. LSD test shows that the provenances are homogeneous, i.e. there are no statistically significant differences in the mean values between them. The smaller range of variation in the properties of these provenances in comparison to other provenances can be partially explained with their genetic similarity which led to similar phenotypic expressions in the interaction with the external factors of the experimental sites.