Progeny evaluation and early selection for plant height in Acacia mearnsii improve genetic gains

Abstract

Acacia mearnsii De Wild. is one of the most widely cultivated forest species in Brazil. Despite its importance, studies on breeding strategies for this species are scarce. Therefore, the aim of this study was to evaluate the progeny and develop early selection strategies for A. mearnsii. Individuals of half-sib progenies were classified according to their genotypic value and selected based on their relative performance. The additive effect was only significant for plant height. The best progenies and plants should be selected based on plant height after approximately 60 days of being in nursery and 2 years of field cultivation. This strategy eliminates the worse progenies, discards inferior genotypes in the nursery, eliminates unselected genotypes based on plant height before flowering, and intercrosses only the best plants in field cultivation. This resulted in an annual genetic gain of 3% for plant height and 2% for diameter at breast height.