The environmental effect on crown shape of common cypress clones in the Mediterranean countries

Crown shape of four different clones planted out in six experimental fields located in five European countries are described and compared using discriminant analysis. The correlations among the considered traits were computed for each clone in each location. The results of the discriminant analysis showed that the locations in which trees have grown have a greater discriminating effect than the clones themselves. It means that the ecological factors that characterize a particular location effectively mould the shape of the tree's crown. The phenotypic correlations between characters were altered when trees grow in different conditions. For one of the clones taken into account these changes are due to the differential phenotypic plasticity of the considered traits. This characteristic may have considerable implications on the breeding programs. A question is whether it is worth the effort to select clones from a particular environment and then use them under very different conditions of habitat.