Genetic control of Acacia mearnsii De Wild. clonal propagation

Plantations of Acacia mearnsii De Wild. show low levels of productivity due to thesignificant differences between plant growth. Therefore, evaluating of clonal propagationstrategies as an alternative to seminal propagation is necessary for the species. The objectiveof this study was to estimate genetic control related to clonal propagation of A. mearnsii anduse a selection index to measure gains for traits related to vegetative propagation and fieldperformance of clonal genotypes. Data were collected during 2021 and 2022 from nurseriesand included mini-cutting productivity per mini-stump (PD), percentage of adventitiousrooting (ENR), and propagule productivity index (PI). In the field, the parameters height (Ht)and diameter at breast height (DBH) were measured at 12 months of age in clonal tests. Basedon the genetic parameter estimates, the existence of variability among A. mearnsii genotypeswas identified for all evaluated traits. The traits PD (h 2 =0.36), PI (h 2 =0.24), Ht (h2=0.20), andDBH (h 2 = 0.13) showed moderate heritability, while only ENR (h 2 =0.06) showed lowheritability. The selection of genotypes for vegetative propagation supported by PI cangenerate selection gains of more than 50%, suggesting the efficacy of using this criterion inearly evaluation and selection of genotypes for propagation in nurseries. The early selectionbased on height can achieve gains of up to 4.7%, depending on the applied selection intensity.The use of the additive selection index considering the traits PI and Ht can be used for earlyselection of superior A. mearnsii genotypes, promoting estimated gains of up to 2.5%.