Stable marker-trait associations for growth across different ages in Eucalyptus cladocalyx through the use of microsatellites

Abstract

Stability of quantitative trait loci (QTL) across different ages is of particular interest in tree breeding programs. This study aimed to identify stable marker-trait associations for growth in 47 half-sib families of Eucalyptus cladocalyx across different ages using microsatellite markers. Total tree height (H) was measured at ages 3, 9, 10 and 13 years (H03, H09, H10 and H13, respectively), while diameter at breast height (DBH) was measured at ages 9, 10 and 13 years (DBH09, DBH10 and DBH13, respectively). Based on a mixed modeling approach (REML/BLUP), growth traits were found to be moderately heritable ranging from h(2) = 0.15 to h(2) = 0.29 for H, and from h(2) = 0.16 to h(2) = 0.22 for DBH. The marker EMBRA208 was statistically consistent at all ages studied for tree height, and the markers EMBRA191, EMBRA208 and EMBRA32 for DBH, indicating high stability across different ages of E. cladocalyx. These results have important practical implications for marker-assisted selection.