Comparisons of genetic parameters and clonal value predictions from clonal trials and seedling base population trials of radiata pine

Abstract

Different methods for predicting clonal values were explored for diameter growth (diameter at breast height (DBH)) in a radiata pine clonal forestry program: (1) clones were analyzed with a full model in which the total genetic variation was partitioned into additive, dominance, and epistasis (Clone Only-Full Model); (2) clones were analyzed together with seedling base population data (Clone Plus Seedling (CPS)), and (3) clones were analyzed with a reduced model in which the only genetic term was the total genetic variance (Clone Only-Reduced Model). DBH was assessed at age 5 for clones and between ages 4 to 13 at the seedling trials. Significant additive, dominance, and epistatic genetic effects were estimated for DBH using the CPS model. Nonadditive genetic effects for DBH were 87% as large as additive genetic effects. Narrow-sense ( b h 2 ) and broad-sense ( b H 2 ) heritability estimates for DBH using the CPS model were 0.14 ± 0.01 and 0.26 ± 0.01, respectively. Accuracy of predicted clonal values increased 4% by combining the clone and seedling data over using clonal data alone, resulting in greater confidence in the predicted genetic performance of clones. Our results indicate that exploiting nonadditive genetic effects in clonal varieties will generate greater gains than that typically obtainable from conventional family-based forestry of radiata pine. The predicted genetic gain for DBH from deployment of the top 5% of clones was 24.0%-an improvement of more than 100% over family forestry at the same selection intensity. We conclude that it is best practice to predict clonal values by incorporating seedling base population data in the clonal analysis.

Modeling additive and non-additive effects in a hybrid population using genome-wide genotyping: prediction accuracy implications

“…In the case of height at 32 months, our results stressed the importance of non-additive effects and confirmed the findings of previous studies of Baltunis et al (2009) with radiata pine and Araujo et al (2012) with E. globulus dealing with growth traits. However, they differed from earlier forest tree studies using full-sib families with clonal replicates and analyzing growth traits, which revealed a very low or limited proportion of non-additive variance, for example, Lepoittevin et al (2011) with maritime pine.…”

Genetic parameters for growth, wood density and pulp yield in Eucalyptus globulus

“…clone) statistical model, described as above for the CP data, has also been applied in the analysis of clonally replicated progeny tests of other forest tree species (e.g. Kumar 2006;Baltunis et al 2008;Callister and Collins 2008;Weng et al 2008). From the UC material, trait estimates of broad-sense heritability b H 2 were obtained by b…”

Unraveling Additive from Nonadditive Effects Using Genomic Relationship Matrices

“…Thus, clonal populations are an alternative to explore the full genetic architecture in these species (Foster and Shaw 1988). Several studies aimed at partitioning genetic variance into its various components detected small dominance and negligible epistatic effects (Foster and Shaw 1988;Mullin et al 1992;Wu 1996;Isik et al 2003Isik et al , 2005Costa E Silva et al 2004, 2009Baltunis et al 2007Baltunis et al , 2008Baltunis et al , 2009Araujo et al 2012). These results do not necessarily imply that such effects are not important.…”