Evaluación del potencial de mejoramiento genético en el crecimiento en altura de Acacia mangium Willd.

In 2009-10, in Ayapel, Planeta Rica and Tierralta, Cordoba department (Colombia) the growth performance in overall height of 90 open-pollinated farnilies of Acacia mangium was evaluated. In these municipalities the climate is classified, according to Holdridge, like tropical dry forest (TDF), except Tierralta that it is tropical moist forest (TMF). During the first year of growth, plants in each farnily were evaluated in progeny tests using a randomized experimental complete block design, with six blocks in each of the three locations. The experimental unit consisted of six open-pollinated plants per farnily, randomly distributed in three spatially separated pairs within each block. The prediction of genetic pararneters individual and of farnilies was conducted by the method BLUP (best linear unbiased prediction) and the variance components by REML (restricted maximum likelihood) procedure using the software SELEGEN. Heritability estimates ranged from <1 to 13%, and between 6 to 68%, for strictly individual heritability (hza) and farnily-mean heritability (hzmp), respectively. Genetic ranking in height of the top 15 farnilies indicates that those of greatest growth were also more stable and had greater adaptability to environments. Results suggest a high potential for improvement at the farnily level in growth and productivity of plantations of A. mangium in the department of Cordoba, Colombia. New measurements in next years are needed to achieve a better genetic selection.