Genetic parameters for height and stem straightness in Pinus taeda Linnaeus in Zimbabwe
1997
Gwaze, D.P. | Woolliams, J.A. (Roslin Inst., Edinburgh, (United Kingdom)) | Kanowski, P.J.
Genetic and phenotypic parameters for height and stem straightness were estimated for Pinus taeda L. in Zimbabwe using the individual tree model DFREML. The data were from 4 progeny tests comprising 140 full-sib families assessed at 1.5, 9.5, 13.5 and 22.5 years. Dominance variance tended to be lower than additive variance for both traits, except for straightness at 1.5 years. Heritability estimates for height were moderate to high (0.14 to 0.73) and peaked at 9.5 years; those for straightness were low at 1.5 years and increased to moderate levels with age (0.01 to 0.33). Individual site heritability estimates were higher than those using data pooled across sites, indicating presence of genotype environment interactions and/or heterogeneity of variances. It is suggested that combining data as in the pooled analyses was not appropriate for this study. Genetic correlations were higher than their phenotypic counterparts in both traits. Age-age genetic correlations for height were high, indicating opportunity for early selection (0.76 to 0.97). Age-age genetic correlations for straightness ranged from -0.05 to 0.94. Genetic correlations between height and straightness were low
显示更多 [+] 显示较少 [-]