Heritability of growth traits in a natural population of the facultative apomictic tree aspidosperma polyneuron

Abstract

Understanding the heritability of growth traits is important in natural populations because it indicates the capacity of natural and artificial selection to alter the average traits in a population. Here, we use microsatellite loci to estimate heritability for total height (H) and root collar diameter (RCD), in juveniles of Aspidosperma polyneuron in two plots (P1, P2) established in a natural population. Heritability was calculated by regression for pairwise differences in traits for the total sample, and only for non-apomictic juveniles. The analysis indicates that heritability based on the entire sample (RCD: P1= 0.266, P2= 0.086; H: P1= 0.168, P2= 0.042) was similar to the sample excluding apomicts (RCD: P1= 0.264, P2= 0.087; H: P1= 0.170, P2= 0.050). However, apomicts generally show better performance, reaching greater RCD and H than non-apomicts. Thus, the natural and artificial selection of apomict individuals are options for population regeneration since they are well adapted to the study environment.