Abstract
The complete randomized design method was used to study the morphological variations in Populous nigra L. on 10 characteristics of the leaves of these nonnative trees to Iraq. Each character which contains 240 samples (3 samples for each one direction of the four) taken from 20 trees (each 10 growing along river sides ) at Sarsung & Zakho sites in Iraqi Kurdistan region was analyzed. The result of statistical analysis using SAS show that there is high level of significant variations for most characters among individual trees between both sites and that a high level of significant variations present between both sites. Again the results reflected significant variations between directions but in lesser level. The results also showed that are one of eastern and southern directions of the first tree in Zakho site gives larger values for studied characters than the other directions of other trees. This is often due to the genetical and environmental factors together. The ultimate wide range of variation patterns suggest the use of individual tree selection method in breeding and improvement programs of this species, so that, we thing it is right to suppose depending those directions from that tree in Zakho site to use their seeds in breeding and improvement of the populous nigra L. trees programs in Iraq.
