QUANTITATIVE GENETIC-PARAMETERS FOR 7 CHARACTERS IN A CLONAL TEST OF SALIX-ERIOCEPHALA .2. GENETIC AND ENVIRONMENTAL CORRELATIONS AND EFFICIENCY OF INDIRECT SELECTION

The relationship between seven characters that are important in biomass production was examined using 20 clones of Salix eriocephala. Biomass was positively correlated with number of stems, number of branches and wood moisture content, with significant genetic correlation coefficients of 0.794, 0.740 and 0.521, respectively. Wood specific gravity was negatively correlated with stem height, stem basal diameter and wood moisture content, with significant genetic correlation coefficients of -0.872, -0.750 and -0.868, respectively. The efficiency of indirect selection via correlated responses were assessed for number of stems, wood moisture content, wood specific gravity, and biomass. Number of stems, number of branches, and wood moisture content were identified as the potential secondary characters to which selection can be applied for more rapid improvement in biomass. No indirect selection, however, was found to be more efficient than direct selection for number of stems, wood moisture content, and wood specific gravity.