Genetic parameters of greenhouse growth and performance of 2-year pinus contorts subsp. latifolia

Stand differentiation, heritabilities and genetic correlations in 16 growth, bud and branch traits in Pinus contorta subsp. latifolia were studied for two growth periods in the greenhouse. Data for analyses were based on 116 open-pollinated families from 33 stands in one breeding region in central Alberta, Canada. Family effect was significant at the 1% level of probability for all traits. The narrow-sense heritabilities (h(i)(2)) from 0.43 +/- 0.09 to 0.71 +/- 0.12 for traits of absolute height and diameter were the highest reported for growth traits in this conifer. In contrast, h(i)(2) varied between 0.15 +/- 0.06 and 0.33 +/- 0.08 for bud, branch and growth increment traits. Except for relative branch length, all traits showed convariation with the other traits. Levels of heritability and genetic correlation suggest that selection procedures that exploit additive genetic variance and covariance might be practised, provided there would be high juvenile-mature correlation for this sample of P. contorta subsp. latifolia.