A novel individual-tree mixed model to account for competition and environmental heterogeneity: A Bayesian approach

Cappa Eduardo Pablo, Munoz Facundo, Sanchez Leopoldo, Cantet Rodolfo J.C.. 2015. A novel individual-tree mixed model to account for competition and environmental heterogeneity: A Bayesian approach. Tree Genetics and Genomes, 11:120, 15 p.

Url - éditeur : https://rdcu.be/b9HFl

Quartile : Q1, Sujet : HORTICULTURE / Quartile : Q1, Sujet : FORESTRY / Quartile : Q3, Sujet : GENETICS & HEREDITY

Résumé : Negative correlation caused by competition among individuals and positive spatial correlation due to environmental heterogeneity may lead to biases in estimating genetic parameters and predicting breeding values (BVs) from forest genetic trials. Former models dealing with competition and environmental heterogeneity did not account for the additive relationships among trees or for the full spatial covariance. This paper extends an individual-tree mixed model with direct additive genetic, genetic, and environmental competition effects, by incorporating a two-dimensional smoothing surface to account for complex patterns of environmental heterogeneity (competition + spatial model (CSM)). We illustrate the proposed model using simulated and real data from a loblolly pine progeny trial. The CSM was compared with three reduced individual-tree mixed models using a real dataset, while simulations comprised only CSM versus true-parameters comparisons. Dispersion parameters were estimated using Bayesian techniques via Gibbs sampling. Simulation results showed that the CSM yielded posterior mean estimates of variance components with slight or negligible biases in the studied scenarios, except for the permanent environment variance. The worst performance of the simulated CSM was under a scenario with weak competition effects and small-scale environmental heterogeneity. When analyzing real data, the CSM yielded a lower value of the deviance information criterion than the reduced models. Moreover, although correlations between predicted BVs calculated from CSM and from a standard model with block effects and direct genetic effects only were high, the ranking among the top 5 % ranked individuals showed differences which indicated that the two models will have quite different genotype selections for the next cycle of breeding.

Mots-clés Agrovoc : théorie Bayésienne, compétition végétale, phytogénétique, amélioration des plantes, amélioration génétique, Pinus taeda

Mots-clés complémentaires : Modélisation Bayésienne, Analyse spatiale

Mots-clés libres : Mixed model, Bayesian analysis, Genetic breeding, Competition, Spatial heterogeneity

Classification Agris : U10 - Informatique, mathématiques et statistiques
K01 - Foresterie - Considérations générales

Champ stratégique Cirad : Hors axes (2014-2018)

Auteurs et affiliations

• Cappa Eduardo Pablo, INTA (ARG) - auteur correspondant
• Munoz Facundo, INRA (FRA) ORCID: 0000-0002-5061-4241
• Sanchez Leopoldo, INRA (FRA)
• Cantet Rodolfo J.C., CONICET (ARG)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/596857/)

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