Selecting for stable and productive families of Eucalyptus urophylla across a country-wide range of climates in Brazil

Abstract

To identify stable and productive Eucalyptus urophylla S.T. Blake families across diverse climate zones in Brazil, we evaluated growth and survival of 322 open-pollinated families derived from 13 genetically improved seed sources in 10 trials across the country. Survival and growth data were analyzed using linear mixed models and REML/BLUP. Survival ranged from 51% to 92%, and the mean annual increment varied from 19 to 46 m3·ha−1·year−1. Although planted in suitable climatic zones, some trials had low survival and (or) productivity. Conversely, the highest productivity was recorded in a zone considered to be of low suitability. These results show the importance of assessing the climatic requirements of eucalypts beyond those determined from analyses of their natural distribution, especially when testing already improved seed sources. A number of productive and stable families were identified based on analysis of the interaction between genotype and environment, and from these, 144 individuals were selected and had their genetic diversity estimated using 19 microsatellite DNA markers. The genetic diversity of these selected trees was equivalent to that observed in previous studies of natural populations of E. urophylla, indicating that breeding programs of E. urophylla in Brazil still retain high levels of diversity for sustainable genetic gains.

Selection of Eucalyptus grandis families across contrasting environmental conditions

“…DBH heritability within each site range from 0.19 to 0.39 is considered intermediate for this growth character. This range is similar to improved E. urophylla families evaluated across ten sites in Brazil (Silva et al 2019), with a range from 0.09 to 0.29, considering mixed mating. The highest DBH heritability was obtained in Itamarandiba-MG, indicating lower environmental effects on phenotypic variation.…”

“…This corroborates results of Rodas et al (2005) that when E. grandis is grown as a pure species, it is not well adapted to the Am climatic condition in Monte Dourado, where high temperatures and humidity favor Cylindrocladium leaf disease. In this site, the disease attacks the trees since the first summer (wet and hot) and probably is the main mortality cause of susceptible material in the climatic conditions of the site, as discussed by Silva et al (2019).…”

Early silvicultural performance of eucalypt species grown in environmental conditions of the tropical dry forest of Colombia

“…Our results agree with those reported by Silva, et al (2019a;2019b) when evaluating survival and growth in 3-year progeny trials of E. urophylla and E. grandis in different climatic zones of Brazil. These authors reported a survival rate of 51 % to 92 % and an MAI of 19 to 46 m 3 •ha -1 •year -1 for E. urophylla and of 28 to 89 % and 20.5 and 48.4 m 3 • ha -1 •year -1 for E. grandis.…”

Elevated CO2 Did Not Stimulate Stem Growth in 11 Provenances of a Globally Important Hardwood Plantation Species

“…Nine Eucalyptus species dominate hardwood plantations around the world due to their fast growth under a wide range of environmental conditions (Harwood, 2011;Müller da Silva et al, 2019), providing considerable capacity as sinks for atmospheric C (e.g., Binkley et al, 2017;Viera and Rodríguez-Saolliero, 2019). One of the most important eucalypt species used in plantations is E. grandis Hill ex Maid (comm.…”