Genetic variation of wood properties in tamarack (Larix laricina (Du Roi) K. Koch)

Genetic variation of tracheid length, specific gravity, latewood percentage, height growth, and ring width among and within four provenances of tamarack (Larix laricina (Du Roi) K. Koch) was investigated in a ten-year-old provenance test that was planted in Thunder Bay, Ontario. Significant genetic variation of tracheid length, height growth, and ring width was found among provenances and among clones within provenances. A south-north trend of decreasing provenance means with increasing latitude was found for tracheid length, height growth, and ring width. Fast-growing provenances generally had longer tracheids than slow-growing provenances. Variation of specific gravity and latewood percentage was not significant among provenances or among clones within provenances. Variance components and broad-sense heritabilities of wood properties due to clones within provenances were larger than those due to provenances. However, variance components and broad-sense heritabilities of growth characteristics due to clones within provenances were smaller than those due to provenances. Positive genetic correlations (r = 0.03 to 0.88) between wood properties and growth characteristics were detected, and the possibility of improvement of both wood properties and wood volume in tamarack was discussed.