Genetic parameters and provenance variation of Pinus radiata D. Don. 'Eldridge collection' in Australia 1: growth and form traits

Growth and form traits data were obtained from eight provenance trials of radiata pine (Pinus radiata D. Don) planted across the radiata pine plantation estate in southeast Australia. The genetic pool included 466 openpollinated families collected from Año Nuevo, Monterey and Cambria provenances on the Californian mainland coast in the USA and from Guadalupe and Cedros islands off the coast of Baja California in Mexico. Early survival of all provenances was around 90%, except for Cedros (<60%). Monterey and Año Nuevo were the best performers at almost all sites. However, good growth performance of Cambria and good stem straightness of Guadalupe on some sites are important results, because the genetic base of the present Australian plantations evidently originated from only Monterey and Año Nuevo. The average estimated single-site heritability for diameter at breast height was 0.22 and 0.32 at juvenile and mature ages, respectively. Heritability estimates for stem straightness and branching ranged from 0.23 to 0.55. Genetic correlation estimates between diameter at breast height (DBH) at juvenile and rotation ages were all >0.80. Estimates of between-site genetic and provenance correlations for DBH were often low, indicating high genotype by environment interaction across trials, consistent with previous Australian studies. However, there was minimal G×E among trials on highaltitude high-rainfall sites and among trials on low-altitude, low-rainfall sites.