GENETIC-PARAMETERS OF GREENHOUSE GROWTH AND PERFORMANCE OF 2-YEAR PINUS-CONTORTA SUBSP LATIFOLIA

Stand differentiation, heritabilities and genetic correlations in 16 g rowth, bud and branch traits in Pinus contorta subsp. latifolia were s tudied for two growth periods in the greenhouse. Data for analyses wer e based on 116 open-pollinated families from 33 stands in one breeding region in central Alberta, Canada. Family effect was significant at t he 1% level of probability for all traits. The narrow-sense heritabili ties (h(i)(2)) from 0.43 +/- 0.09 to 0.71 +/- 0.12 for traits of absol ute 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 r elative branch length, all traits showed convariation with the other t raits. Levels of heritability and genetic correlation suggest that sel ection procedures that exploit additive genetic variance and covarianc e might be practised, provided there would be high juvenile-mature cor relation for this sample of P. contorta subsp. latifolia.