Provenance hybridisation in Pinus caribaea var hondurensis in Queensland

A total of three control-pollinated provenance hybrids made amongst Mountain Pine Ridge (MPR), Coastal and Guanaja provenances of Pinus caribaea var. hondurensis were studied against a control (open-pollinated MPR provenance) in two Queensland sites at 6-7 years of age for growth, and stem and crown quality. The provenance hybrids were tested with the main objective to incorporate some desirable complementary attributes of Coastal and Guanaja germplasm into the advanced MPR population. Provenance hybrids performed consistently across the two sites. An inter-provenance hybrid, MPR × Coastal was better than MPR for almost all the traits examined and showed positive heterosis, ie. superior to midparent value. The other two hybrids, Coastal × Coastal and Coastal × Guanaja grew at least as well as MPR but had strikingly fewer crown defects. In addition, the wind-firmness of Coastal × Guanaja was promising at four years of age. Implications pertinent to breeding P. caribaea var. hondurensis in Queensland were discussed.