Genetic Variance Among Selected Cottonwood Clones: Seven-Year-Results

Fifty-one previously tested cottonwood clones from throughout the lower Mississippi River Valley were tested on Island No. 3 in Carlisle County, Kentucky. The clonal component of variation was highly significant for all traits and on the average accounted for 31 percent of the total variation. Inter-tree competition and the age-three thinning seem to have played a major role in stand development and estimates of genetic parameters. The genetic and phenotypic correlations and correlated responses indicate that clonal selection based on height at ages one and three would be very ineffective for volume at age seven. Selections at age five for either diameter or volume will yield nearly as much gain as direct selection for volume at age seven. Additional Keywords: Populus deltoides, broad-sense heritabilities, genetic correlations, correlated response, genetic gain.

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Author(s): Randall J. Rousseau

Publication: Tree Improvement and Genetics - North Central Tree Improvement Conference - 1987