Estimates of genetic parameters and gains expected from selection of juvenile characters in rubber tree progenies

Abstract

The objective of this paper was to estimate quantitative genetic parameters for growth and yielding characters in juvenile half-sib progenies of rubber trees [Hevea brasiliensis (Willd ex. Adr. de Juss.) Müll. Arg.]. Seventeen genotypes were randomly selected from a 35-years-old asiatic base population established in the Experimental Center of Campinas, SP, Brazil. Open pollinated seeds were collected and planted at the Experimental Station of Pindorama under randomized complete blocks design. The characters studied were: yield folowing Hamaker-Moris-Mann (HMM) test (PPB), girth at 50 cm from the ground (CCC), bark thickness (ECC), total number of latex vessels rings, density of latex vessels per 5 mm per ring averaged over all rings (DEN), diameter of the latex vessel rings (DIA), average distance between consecutive latex vessel rings (DMA), crown evaluation (ACP), leaf area (AFO) and leaf petiole lenght (CPE). Results indicated significant differences for yield, bark thickness and girth. Also the different types of heritabilities were greater for yield, bark thickness and girth. The genetic gain estimates for selection among and within the progenies showed considerable genetic advances for the studied characters, revealing the possibility of successful selection.