Initial productivity and genetic parameters of three Corymbia species in Brazil: designing a breeding strategy

Abstract

The survival, initial productivity and the genetic parameters of <i>C. citriodora</i> subsp. <i>citriodora</i> (CCC), <i>C. citriodora</i> subsp. <i>variegata</i> (CCV) and <i>C. torelliana</i> (CT) were used to develop a breeding strategy for the <i>Corymbia</i> species. Survival, height and diameter at breast height (DBH) data were assessed 24 and 36 months after planting and the mean annual volume increment estimated in three trials. Longitudinal DBH data analysis was applied to each trial individually, to identify the best and the poorest families at both ages. The mortality ranged from 5% in CT to 27% in CCC and the mean annual increment varied from 17.8 to 20 m<sup>3</sup> ha-<sup>1</sup> year<sup>-1</sup> at 36 months after planting. The 36-month narrow-sense heritability (h<sub>a</sub><sup>2</sup>) was high for CCV (0.69±0.17), moderate for CCC (0.41±0.11) and low for CT (0.21±0.09). The genetic parameters indicated the need for different breeding strategies, for each species. Selecting the best families while roguing the poor families allowed forward selection of CCC and CCV. It was possible to select good CT trees for hybrid breeding, however, improving the species population requires focusing on increasing the effective size and expanding the genetic variability in the CT population.

Initiation of breeding programs for three species of Corymbia: Introduction and provenances study

“…The three species exhibited high survival, above 95% (Table 2), indicating high adaptation, without significant differences for survival regarding seedlots/provenances. Similar studies have reported comparable survival values for CH (93%) in the region (Silva et al 2017), as well as CCV (93%) and CT (95%) in the same location (Araujo et al 2021). However, it is noteworthy that CCV survival rates under different Brazilian climatic conditions vary widely from 50 to 96% three years after planting (Silva et al 2017).…”

“…Species of the genus Corymbia have growth potential under several Brazilian climatic conditions. However, their potential has only been explored recently (Silva et al 2017, Tambarussi et al 2018, Araujo et al 2021. Diversification of species and genera for commercial planting is a way to reduce plantation vulnerability to biotic and abiotic stresses.…”

Genetic structure and diversity in wild and breeding populations of Eucalyptus urophylla

“…Therefore, the origin/provenance has a strong influence on the genotype performance, tolerance to biotic and abiotic stresses, and wood quality. The effect of provenance has been observed and reported for several species in different countries, such as in Corymbia citriodora sub variegata (Araujo et al 2021;Silva et al 2022), Eucalyptus grandis (Ferreira 2015;Silva, Marco, et al 2019), E. pellita (Nieto et al 2016), E. pilularis (Carnegie, Johnson & Henson 2004), including E. urophylla itself (Hodge & Dvorak 2015).…”

GGE biplot-based genetic selection to guide interspecific crossing in Corymbia spp.

“…The narrow-sense heritability between progenies ( ℎ "# $ ) values for DBH in half-sibling progenies of Corymbia was lower than the ones reported by Araujo et al (2020), which varied from 0.41 to 0.69. According to Lima et al (2019), the traditional mixed model methodology commonly overestimate genetic parameters estimates and consequently narrowsense heritability for growth traits in comparison to methodologies that consider the genomic relationship matrix.…”