Genetic parameters of growth and survival in Acacia saligna shrubs
Acacia species have valuable agronomic characteristics, such as the tolerance to unfavorable environmental conditions. In this study, genetic parameters and selection response in Acacia saligna shrubs were investigated in two arid environments of northern Chile: Cuz-Cuz and El Tangue. The quantitative traits were assessed in 5 year-old shrubs. A Bayesian approach, implemented using Gibbs sampling algorithm, was used in the data analysis. The tree survival was 87.3% and 81.8% in Cuz-Cuz and El Tangue, respectively, confirming the potential of A. saligna in northern Chile. The estimates of posterior mode of the heritability ranged from h2=0.13 (survival) to h2=0.25 (shrub crown diameter). Estimated genetic gain (individual tree selection) ranged from 6 to 14% (selection intensity of 20%). Bayesian credible intervals (p=95%) for genotype-environment correlations included zero, indicating a significant interaction for survival, crown diameter and height. Shrub selection in multipurpose planting will depend on optimizing economical traits by selecting genotypes that perform well on a particular environment.