Adaptação e seleção de matrizes em um teste de espécies e procedências de eucalipto

Abstract

The introduction of species and provenancestests carried out between the 1970s and 1980s helped in the development of Brazilian eucalyptus forestry. This study aimed to identify the potential of different species and origins of Corymbia and Eucalyptus for the region of LavrasMG, to investigate the existence of genetic variability to start a breeding program and the selection of superior individuals to collect seeds and propagules for the formation of an orchard to produce improved seeds and future tests of species and progenies. The species collection is located in Lavras-MG and comes from a test of species and provenances of eucalyptus implanted in the year 1974, coming from the program of introduction and reintroduction of species of eucalyptus and its genera organized by the Brazilian Institute of Forest Development (IBDF) originally containing 27 species from various sources in Oceania. For the identification of the species adaptation potential, a census was carried out in the year 2018, counting survival, diameter at breast height (DBH) and basal area (g). The community characterization was performed through descriptive statistics, showing the diametric and basal area structures of the community and by species. The selection of matrices was restricted to the species that better adapted on the region of Lavras. The criterion of 10 matrices per species was established, therefore, the intensity of selection was calculated separately for each species. The selection was performed according to the DBH through the mass method and aided by computational model in a line and column design. The comparison of the methods was performed according to the Spearman correlation and through the parameters: selection differential, selection gain and prediction of new mean for the character. The species Corymbia intermedia, Eucalyptus phaeotricha, Eucalyptus pilularis, Eucalyptus grandis and Eucalyptus acmenoides stand out as potencies for the region of Lavras at 44 years of age. Among the provenances are Corymbia citriodora (102608) from Heberton, C. intermedia (7146) from Brisbane, Corymbia maculata (6169) from Brisbane, Corymbia torelliana (4) from Atherton, E. grandis from Bellthorpe (10696), Coff's Harbor (9753) and Kygole (9535), E. phaeotricha (9782) from Atherton, and the provenances of E. pilularis from Cassino (9463), Beerburrum (34) and Brisbane (37) as which had surgeries above 60%. There is a large genetic variation coefficient for DBH ranging from 10% to 18% between the selected species desirable for the initiation of a breeding program, though a low heritability of the observed characteristic between ranging from 0.08 to 0.15. The Spearman correlation between the ordering of the methods was close to zero for most species, which demonstrates the distinction between the methods. For the E. phaeotricha species, however, the correlation was 0.981 which shows a similarity between the orders. By estimating the environmental variation and the failure rate method assisted by statistical model in design row and column is the most recommended for the selection of superior individuals.