Patterns of genetic variation in bud flushing of Abies alba populations

Abstract

Abstract: In the spring of 2007, 51 full-sib and six half-sib families of European silver fir were obtained through controlled and open pollinations from the same clones in a seed orchard. Genetic variation and parameters for bud flushing were determined in two progeny tests established in a nursery. The results indicate a high genetic control of bud flushing of European silver fir. Both the additive and the dominance genetic variances were major sources of genetic variation. The additive genetic variance was greater for open-pollinated than for full-sib progeny, representing 50-95% of phenotypic variance. Narrow-sense individual heritability estimates for control-pollinated progenies ranged from 0.14 to 0.64, while the full-sib family heritability ranged from 0.09 to 0.40. In the open-pollinated progenies, the values of individual and family heritability were higher than those in control-pollinated progeny and ranged from 0.50 to 0.95 for both. In both experiments, genetic parameters were higher for bud flushing at the beginning of the growing period than at later stages. The genetic correlations between bud phenology and growth traits were positive and significant in control-pollinated progeny but not significant in open-pollinated progeny. Positive significant correlations between control-pollinated and open-pollinated progeny showed a maternal effect. Bud flushing was negatively correlated with geographic and climatic parameters of the site of parents’ origin, accounting for 83-97% of the total variation of this adaptive trait.