Early growth and genetic variation of mahogany (swietenia macrophylla) in progeny tests planted in northern mindanao,Philippines

Mahogany (swietenia macrophylla) progeny trials were established at butuan and cagayan de oro in mindanao (philippines) to examine genetic variation in growth and form traits of progenies from 73 families of six plantation seed sources. at age 50 months,mean diameters were 12.1 and 4.5 cm,while mean heights were 9.4 and 3.8 m for progenies at butuan and cagayan de oro respectively. lianga and bislig seed sources consistently ranked among the best in growth. additive genetic coefficients of variation for diameter were 6.5 and 10.6% and for height,6.5 and 13.8% at butuan and cagayan de oro respectively. narrow-sense heritability (h2) for diameter was 0.29 at butuan and 0.29 at cagayan de oro. for height,h2 was 0.37 at butuan and 0.43 at cagayan de oro. cross-site heritability of growth traits was significantly lower for both diameter (h2 = 0.11) and height (h2 = 0.26) due to genotype-by-environment interactions. type-b genetic correlations for height and diameter were 0.24 and 0.34 respectively. wood basic density at butuan was moderately heritable (h2 = 0.30). infusion and testing of new germplasm from natural range mahogany in the americas are recommended to broaden the base population for tree farms and agroforestry plantations in the country. © forest research institute malaysia.