Genotype-by-environment interactions and the dynamic relationship between tree vitality and height in northern Pinus sylvestris

Abstract

Tree health and growth rate must both be considered in Scots pine breeding for harsh areas such as northern Sweden. Univariate (UV) and multivariate (MV) multi-environment trial (MET) analyses of tree vitality (a measure of tree health) and height (a measure of growth rate) were conducted for four series of open-pollinated Scots pine progeny trials (20 trials total), to evaluate age trends, patterns, and drivers of genotype-by-environment interaction (G × E). The lowest standard errors were obtained for the MV MET analyses, indicating that MVanalyses are preferable to UVanalyses. By incorporating factor-analytic structures, the most complex data sets could be handled, suggesting that factor-analytic analyses are preferred for evaluation of forest progeny trials. We detected strong patterns of G × E for both tree vitality and height, and the driver of G × E was found mainly to be differences in degree day temperature sum, such that G × E was higher between trials with more contrasting temperature sums. The genetic correlations, between vitality and height within sites, were generally positive and were driven by the harshness of the trial; mild trials had lower genetic correlations than did harsh trials. The sign of the across-site genetic correlations between vitality and height changed from positive to negative in some cases, as the differences between the temperature sum of the trials increased. These findings support the hypothesis that tree height assessed in harsh environments with low survival is likely to reflect health and survival ability to a greater extent than growth capacity.

Understanding the role of ecotypic factors in the early growth of Pinus sylvestris L.

“…Correlations were estimated to be 0.51, and breeding values of families were predicted (Alan et al 2009). The genetic correlations between vitality and height within sites were generally positive and were driven by the variably harsh environments of the trials under investigation (Calleja-Rodriguez et al 2019). This finding supports our results of the stable balance between ecotypes' height at both test sites, as various local climates and soils most likely shaped these local adaptations.…”

“…Besides the importance of age-to-age correlation for breeding and early testing, interactions among various traits and their further interaction with the environment are key for understanding adaptation. In Sweden, the dynamic relationship between tree (Pinus sylvestris) vitality and height was recently examined (Calleja-Rodriguez et al 2019). The authors evaluated the genotype by environment interaction (G × E) and detected positive correlations between vitality and height.…”

Progeny testing of Pinus sylvestris L. of seed orchard in different environmental conditions

“…This indicates a more important role of adaptation of local genotypes to harsh environmental conditions, compared to their growth rate. Similar results were obtained when testing Scots pine in harsh areas such as northern Sweden (Calleja-Rodriguez et al, 2019). Data research support the hypothesis that tree height, assessed in harsh conditions with low survival, is likely to reflect health and ability to survive to a greater extent than growth rate.…”

Evaluation of the efficiency of genomic versus pedigree predictions for growth and wood quality traits in Scots pine

“…Wood properties were assessed for a subset of 694 progeny trees and the micro-environmental effects were scaled for the raw data by removing the variation of the experimental design features and post-block effects. The environmentally adjusted phenotypic data (predicted values of each tree) were used for the genetic analysis [104][105][106][107].…”