Summary: Estimate of genetic parameters were computed for the trait of average increment in six clonal tests of black poplars, established with different genotype mixtures, different spacings and seedlings age, at the plantation age of 14 years. Estimate of heritability (h2) for the average increment has shown a high degree of genetic control for this trait. Values of genetic heterogeneity were from h2 = 0,47 to h2 = 0,98, depends on experiment and methods of estimations. Realized experimental genetic gain (D G) was much more higher compared with the calculated expected genetic gain. For reason of securing stability of the ecosystem and decreasing the biological risk, priority was given to the five superior clones with diversified genetic constitutions in relation to establishing monocultures, regardless of the possibility of realizing lesser genetic gain through multiclonal plantations with mosaic scheme. Key words: heritability; genetic gain; black poplar clonal tests |