Evaluation of interspecific hybrids of palm oil reveals great genetic variability and potential selection gain

The aim of the experiment was to evaluate genetic variability between and within interspecific hybrids, and identify the best hybrids in order to select the best parents. The experiment consisted of three trials in a randomized block design with 16 treatments, 3 common witnesses and 4 replications, totaling 42 treatments of interspecific hybrids (full-sib progenies) of caiaué and oil palm (Elaeis guineensis × Elaeis oleifera). The experimental plot consisted of 12 plants. It was evaluated weight of bunches per plant (WBP), the number of bunches per plant (NBP) and the mean weight of bunches per plant (MWB) for two crop years (2010 and 2011). Variance components, heritability and coefficients of variation were calculated to ascertain the genetic variability. In order to verify the genetic diversity, it was used the Tocher and UPGMA clustering methods. The selection gain was calculated using four methods: combined selection, selection between and within, mass selection and stratified mass selection. Analysis of variance showed that there was genetic variability between and within half-sib families. The heritability was 0.9, 0.9, and 0.93 for NBP, WBP and MWP, respectively. Combined selection promoted greater gain, followed by mass selection, stratified mass selection and selection between and within all variables. The partial correlation between NBP and WBP, and WBP and MWB was 0.95 and 0.96, respectively, and between NBP and MWB was −0.94. Through UPGMA and Tocher cluster analysis, 15 groups were formed. The interspecific hybrids of oil palm were RUB 1211, RUB 1215, RUB 1212 and RUB 1209 for NBP; RUB 1210, RUB 1274, RUB 1199 and RUB 1232 for WBP; and RUB 1271, RUB 1232, RUB 1210 and RUB 1237 for MWB