IMPLICATIONS OF THE GENOTYPE-ENVIRONMENT INTERACTION EFFECTS ON EUCALYPTUS CLONE SELECTION

Abstract

This work aimed at estimating clones x environments effects, their implications on selection and verifying the efficience of Toler’s (1990) metodologie. The mean annual yield increase (m3/ha.year) of two groups of clone experiments were used in the study. The GXA interaction was significant in both experiments, but it was more pronounced in the experiment with greater number of clones. The clones x environment interaction affected in the selection, because the correlated response to selection in one environment observed in another was always lower than the gain of direct selection. However, even in the correlated response cases, the expected percentage gain was expressive, indicating that it is possible to identify clones with wide adaptation. The Toler’s (1990) metodologie was efficient in identifying clones with greater stability. The clones were classified in five groups, according to the estimates of the stability parameters. The majority of the clones, at the two ages, had their performance explained by a single regression line, i.e., a similar pattern of response to environmental improvement in favorable and unfavorable environments.