Pre-breeding of Imbuya Populations

Abstract

Imbuya (Ocotea porosa Nees et Martius ex. Nees, Lauraceae) is a species under extinction of the Mixed Ombrophylous Forest, whose wood owns high economic value. The objective of this work was to discuss precocious individual genetic selection utilizying Selegen REML/BLUP software in germoplasm of Colombo, PR, Canoinhas and Caçador, SC, populations. Results showed that 1182 selected genotypes (42,9 %) were from Colombo, 1004 (36,4 %) genotypes were from Canoinhas and 572 (20,7 %) from Caçador, totalyzing 2758 selected genotypes. Estimates of variance components showed that additive genetic variance within provenances (Va=6,62) is higher than variance among provenances (Vproc.=1,33), indicating the possibility of predominance of alogamy in the studied populations. Individual heritability in narrow sense in the block (h2a), that is, from additive effects,was 0.29 ± 0.04. Individual genetic variance coefficient (CVgi) was 18,72. Ranking of 50 superior genotypes showed a genetic gain from 5.66 cm to 8.72 cm, with estimates of averages in the next  generation varying from 19.04 cm to 22.45 cm (increment ranging from 41.9 % to 63.46 %). Colombo provenance contributed with 56 % of 50 superior genotypes, Canoinhas with 40 % and Caçador with 4%.