Genotype x environment interaction in European black alder (Alnus glutinosa (L.) Gaertn)

A subset of 17 provenances from an on-going range-wide provenance study of European black alder (Alnus glutinosa) was evaluated in three locations (Iowa, Illinois and Wisconsin) for growth (total height, height growth rates, diameter and volume) and raw biomass properties (field moisture content, maximum moisture content, specific gravity and stem biomass) as well as leaf tissue nitrogen and flower production;Significant differences were found among provenances for all the traits except bark and field moisture contents. The Iowa location had significantly higher mean performances than either southern Illinois or northern Wisconsin locations. Combined analysis over years and locations showed no significant provenance x environment interaction for the raw biomass properties except for maximum moisture content. Growth properties such as height and diameter were positively correlated with each other. Very low correlations were obtained between growth and biomass properties. Leaf tissue nitrogen, bark content and field moisture content had negative correlations with many of the other variables;Estimates of broad sense heritabilities ranged from 0.03 to 0.93 for the different traits within locations and across locations and years. The moderate levels of heritability estimates yield fairly high predicted genetic gains, indicating that genetic improvements are possible for Alnus glutinosa when grown in North Central United States;Stability analysis revealed that the southern European provenances had above average stability while the northern seed sources had below average stability for total height measurements. The German and Danish sources, and two Yugoslavian sources showed average stability over all locations. Cluster analysis grouped Iowa and Illinois into one breeding zone and northern Wisconsin into another, while location: location genotypic correlations indicated that Wisconsin and Illinois could not be in the same breeding zone. However, two concurrent breeding programs are possible for Iowa location, whereby selections could be made for production in Wisconsin and southern Illinois