Inheritance Pattern of Growth and Wood Traits in Teak (Tectona grandis L.f.)

Inheritance pattern of wood traits, especially heartwood/sapwood percentage and specific gravity and interactions of wood traits with other growth traits were investigated in a 27-year-old half-sib progeny trial of teak. Wood traits showed highly significant variation for specific gravity, heartwood and sapwood percentage at family level. There was non-significant family vs. replication variation for these traits. Among the growth traits, there was significant variation for height and girth. Families and individual trees showed varying levels of heritability. Among the growth traits, height showed high heritability (individual tree heritability, h((i))(2) = 34.3%; family heritability, h((f))(2) = 34.1%) followed by girth (h((i))(2) = 19.4%; h((f))(2) = 31.4%). Among the wood traits, maximum heritability values were obtained for sapwood percentage (h((i))(2) = 76.6%; h((f))(2) = 70.7%) and heartwood percentage (h((i))(2) = 76.9%; h((f))(2) = 69.7%). Specific gravity exhibited heritability values of 29.1 and 41.8%, at individual tree and family level, respectively. Family heritability was higher than single-tree heritability for specific gravity; single-tree heritability exceeded family heritability for heartwood percentage. Specific gravity exhibited significant positive genotypic correlation with heartwood percentage suggesting that improvement in heartwood percentage would lead to a correlated improvement in specific gravity. Heartwood percentage showed significant positive correlation with growth traits viz., height and girth. Some of the families showed good GCA for growth and wood traits investigated. The good general combiners identified in the present study can be used for establishment of advanced generation seed orchards and breeding arboreta for improvement of teak for specific or combination of above traits.