Mid-rotation performance of pinus caribaea var. hondurensis hybrids with both p. oocarpa and p. tecunumanii: hybrid superiority, stability of parental performance and potential for multi-species synthetic breed

Abstract

F hybrid progeny between Pinus caribaea var. hondurensis (PCH) and both P. oocarpa (POOC) and P. tecunumanii (PTEC) established in field tests at two locations in Queensland were used to evaluate growth relative to PCH controls, and to estimate genetic parameters for the hybrid populations. These two PCH hybrids showed significantly greater growth (diameter and height) than the PCH controls in three of the four field tests, growing at the two locations. The PCH x PTEC hybrids showed greater productivity than the PCH x POOC hybrids when compared to the PCH controls. Heritability estimates for growth were low to moderate for both hybrid combinations with the amount of additive variance increasing with time, as did the proportion of additive to non-additive variance. The performance of PCH parents was maintained across-sites for growth, wind-firmness and straightness regardless of the species (PCH, PTEC or POOC) to which they were mated. PCH parents performed similarly across-sites with high additive and dominance genetic correlations between sites for growth traits, and the genetic correlations were high between diameter at 5 years and both diameter and height at 10 years of age. Additionally, strong correlations were found for the common PCH parents when crossed with PCH, POCC or PTEC. Evaluation of growth and the associated genetic parameter estimates support the inclusion of these taxa in a multi-species synthetic breed for site-specific deployment in central and southeast Queensland