Genotype-environment Interaction and Stability in Growth of Hybrid Aspen Clones
Forest Ecology and Management
Clonal repeatabilities, stability parameters and clone–site interactions for height and basal diameter were investigated in 3- and 4-year-old trees in four hybrid aspen clonal trials in southern Finland. The four field trials consisted of 24 aspen hybrid clones (Populus tremula×Populus tremuloides) and one P. tremula clone. There were differences in height and diameter growth among the trials on agricultural and forest land. The height increment during the third year was 66% higher, and the diameter increment 50% higher on forest land than agricultural land. The ranking of clones changed across sites, indicating significant site×clone interactions in height and basal diameter. Clone×site interaction were highly significant (P<0.001) in the overall analysis of variance. The variance component for the clone×site interaction was twice as high as that of clones for height and basal diameter in the second and third years, or for their increments during the third year. Clonal repeatability at age 4 was 0.64 for height, and 0.53 for basal diameter. Expected genetic gains of 17% for height growth increment during third year can be expected from selecting fast growing clones.
Yu, Q. and Pulkkinen, P. 2003. Genotype-environment interaction and stability in growth of hybrid aspen clones. For. Ecol. Manage. 173, 25- 35.