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Growth potential and genetic parameters of four Mesoamerican pines planted in the Southern Hemisphere


GR Hodge
WS Dvorak

Abstract

Summary results are reported from a total of 319 provenance/progeny tests of Pinus tecunumanii, P. maximinoi, P. patula and P. greggii that were established on sites in Brazil, Colombia and South Africa. Tests were measured for the growth traits height, diameter at breast height (DBH) and volume at ages 3, 5 and 8 years. At a particular age, correlations among height, DBH and volume were very high (from 0.80 to 0.99) at both the provenance and additive genetic levels, and the three growth traits also had similar heritabilities. Volume at age 3 was highly correlated with age 8 volume (around 0.80), and correlations of age 5 volume with age 8 volume were near 0.95. Low-elevation P. tecunumanii had very high between-country correlations both at the provenance and genetic level (around 0.80 to 1.00). Between-country genetic correlations for most other species were around 0.60. Two of the four species, P. tecunumanii and P. maximinoi, grew substantially faster than the commercial controls planted with the progeny tests (i.e. genetically improved P. taeda in Brazil, and improved P. patula in Colombia and South Africa). Pinus greggii var. australis also demonstrated commercial potential on sites in southern Brazil and South Africa. For all species, the best provenance produced 10–20% more volume than the population mean. In all species, additive genetic variation was substantial, and additional genetic gain could be made by family and within-family selection in an intensive tree-breeding effort.

Southern Forests 2012, 74(1): 27–49

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eISSN: 2070-2639
print ISSN: 2070-2620