Selection strategies for growth characters and rubber yield in two populations of rubber trees in Brazil

Abstract

The objective of this work was to evaluate the genetic parameters and estimate genetic gains in two populations of Hevea brasiliensis. The first population of the study is originated from the primary forest of Rio Branco – Acre (wild population – PS), and the other population is originated from clonal matrices (improved population – PM). Thirty-seven progenies were evaluated at 23 years for PS. For PM, 31 progenies at eight years of age were evaluated for growth traits and dry rubber yield. Estimates of the genetic parameters were made using the univariate linear mixed-model additive model REML/BLUP and gains in selection by the Multi-Effects Index (MEI) method. The selection strategies of 50%, 40% and 22% of individuals for the character of dry rubber yield (PBS) and stem perimeter (PAP) using the multi-effects index revealed high and low selection gains in both populations. For MP, the strategy of selection between and within progenies was more appropriate and for PS, the individual selection. The gains obtained in the selection were 54% for the PBS character in the improved population of 0.46% for the PAP character for the wild population.