Abstract
The use of resistant genotypes is one of the main methods of disease control in Brazil, the genetic improvement, aiming to obtain new genotypes that are resistant is fundamental to supply this demand. Therefore, the objective of this work was to estimate the genetic parameters of the variables: resistance to canker caused by Chrysoporthe cubensis and leaf spot caused by Cylindrocladium spp. and Kirramyces epicoccoides, and to evaluate their implications for the genetic improvement strategy of Eucalyptus grandis. An open pollination progeny test was installed in two locations in the state of São Paulo, in the regions of Anhembi and Itatinga. The test was carried out in randomized blocks, with 176 progenies and three witnesses, one per plot, with 30 repetitions in Itatinga and 28 repetitions in the Anhembi region. The canker resistance was assessed at 12, 24 and 29 months of age in the Anhembi region and at 15, 27 and 32 months of age in the Itatinga region. The resistance to leaf spot was evaluated. at 12 and 24 months of age in the Anhembi region and at 15 and 27 months of age in the Itatinga region. The genetic parameters were estimated using the SELEGEN REML/BLUP® software. It was found out, with the same selection population for the Itatinga region, estimates of genetic parameters indicate greater potential for the selection of resistant genotypes for canker and leaf spot. However, for the edaphoclimatic conditions of the Anhembi region, this population has a lower selection potential, which is evidenced by the low values of the estimated average progeny and individual heritability. In the region of Itatinga, values of average progeny and individual heritability were obtained for resistance to canker and leaf spot, which varied from moderate to high, indicating that there may be good gains with the selection in this location.
Keywords:
Eucalyptus grandis; Selection; Heritability; Disease
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